Restore chan_dahdi native bridging and PRI tromboned call elimination.

Created a native_dahdi bridging technology for use with the new bridging
API.

The new bridging technology is part of the chan_dahdi channel driver
because it is very specific to that driver.  Rather than include the new
code directly into chan_dahdi.c the new bridge technology is in its own
file and linked into chan_dahdi.so.  A large part of this change is the
mechanical process of moving declarations around so chan_dahdi.c can be
split up into more files later.

* Changed the bridging core to pass NULL frames into the channel
technologies instead of discarding them.  The channel technologies may
need the proding to determine if their configuration is still valid.

(closes issue ASTERISK-21886)
Reported by: Matt Jordan

Review: https://reviewboard.asterisk.org/r/2681/


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@395154 65c4cc65-6c06-0410-ace0-fbb531ad65f3

7 files changed, 1829 insertions, 1132 deletions

diff --git a/bridges/bridge_softmix.c b/bridges/bridge_softmix.c
index cf891c668..b2d321815 100644
--- a/bridges/bridge_softmix.c
+++ b/bridges/bridge_softmix.c
@@ -623,6 +623,9 @@ static int softmix_bridge_write(struct ast_bridge *bridge, struct ast_bridge_cha
 	}
 
 	switch (frame->frametype) {
+	case AST_FRAME_NULL:
+		/* "Accept" the frame and discard it. */
+		break;
 	case AST_FRAME_DTMF_BEGIN:
 	case AST_FRAME_DTMF_END:
 		res = ast_bridge_queue_everyone_else(bridge, bridge_channel, frame);
diff --git a/channels/Makefile b/channels/Makefile
index 10d487cfb..154d52e53 100644
--- a/channels/Makefile
+++ b/channels/Makefile
@@ -1,6 +1,6 @@
 #
 # Asterisk -- An open source telephony toolkit.
-# 
+#
 # Makefile for channel drivers
 #
 # Copyright (C) 1999-2006, Digium, Inc.
@@ -72,10 +72,19 @@ dist-clean::
 
 $(if $(filter chan_iax2,$(EMBEDDED_MODS)),modules.link,chan_iax2.so): $(subst .c,.o,$(wildcard iax2/*.c))
 $(subst .c,.o,$(wildcard iax2/*.c)): _ASTCFLAGS+=$(call MOD_ASTCFLAGS,chan_iax2)
+
 $(if $(filter chan_sip,$(EMBEDDED_MODS)),modules.link,chan_sip.so): $(subst .c,.o,$(wildcard sip/*.c))
 $(subst .c,.o,$(wildcard sip/*.c)): _ASTCFLAGS+=$(call MOD_ASTCFLAGS,chan_sip)
-$(if $(filter chan_dahdi,$(EMBEDDED_MODS)),modules.link,chan_dahdi.so): sig_analog.o sig_pri.o sig_ss7.o
-sig_analog.o sig_pri.o sig_ss7.o: _ASTCFLAGS+=$(call MOD_ASTCFLAGS,chan_dahdi)
+
+# Additional objects to combine with chan_dahdi.so
+CHAN_DAHDI_OBJS= \
+	$(subst .c,.o,$(wildcard dahdi/*.c))	\
+	sig_analog.o	\
+	sig_pri.o	\
+	sig_ss7.o	\
+
+$(if $(filter chan_dahdi,$(EMBEDDED_MODS)),modules.link,chan_dahdi.so): $(CHAN_DAHDI_OBJS)
+$(CHAN_DAHDI_OBJS): _ASTCFLAGS+=$(call MOD_ASTCFLAGS,chan_dahdi)
 
 ifneq ($(filter chan_h323,$(EMBEDDED_MODS)),)
 modules.link: h323/libchanh323.a
diff --git a/channels/chan_dahdi.c b/channels/chan_dahdi.c
index ac8695369..0806ca570 100644
--- a/channels/chan_dahdi.c
+++ b/channels/chan_dahdi.c
@@ -62,13 +62,8 @@ ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
 #else
 #include <sys/signal.h>
 #endif
-#include <sys/ioctl.h>
-#include <sys/stat.h>
 #include <math.h>
-#include <ctype.h>
 
-#include <dahdi/user.h>
-#include <dahdi/tonezone.h>
 #include "sig_analog.h"
 /* Analog signaling is currently still present in chan_dahdi for use with
  * radio. Sig_analog does not currently handle any radio operations. If
@@ -90,11 +85,10 @@ ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
 #endif
 #endif	/* defined(HAVE_SS7) */
 
-#ifdef HAVE_OPENR2
+#if defined(HAVE_OPENR2)
 /* put this here until sig_mfcr2 comes along */
 #define SIG_MFCR2_MAX_CHANNELS	672		/*!< No more than a DS3 per trunk group */
-#include <openr2.h>
-#endif
+#endif	/* defined(HAVE_OPENR2) */
 
 #include "asterisk/lock.h"
 #include "asterisk/channel.h"
@@ -131,6 +125,8 @@ ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
 #include "asterisk/features_config.h"
 #include "asterisk/bridging.h"
 #include "asterisk/stasis_channels.h"
+#include "chan_dahdi.h"
+#include "dahdi/bridge_native_dahdi.h"
 
 /*** DOCUMENTATION
 	<application name="DAHDISendKeypadFacility" language="en_US">
@@ -422,7 +418,7 @@ static struct ast_jb_conf global_jbconf;
 /*! \brief Signaling types that need to use MF detection should be placed in this macro */
 #define NEED_MFDETECT(p) (((p)->sig == SIG_FEATDMF) || ((p)->sig == SIG_FEATDMF_TA) || ((p)->sig == SIG_E911) || ((p)->sig == SIG_FGC_CAMA) || ((p)->sig == SIG_FGC_CAMAMF) || ((p)->sig == SIG_FEATB))
 
-static const char tdesc[] = "DAHDI Telephony Driver"
+static const char tdesc[] = "DAHDI Telephony"
 #if defined(HAVE_PRI) || defined(HAVE_SS7) || defined(HAVE_OPENR2)
 	" w/"
 	#if defined(HAVE_PRI)
@@ -445,33 +441,6 @@ static const char tdesc[] = "DAHDI Telephony Driver"
 
 static const char config[] = "chan_dahdi.conf";
 
-#define SIG_EM		DAHDI_SIG_EM
-#define SIG_EMWINK 	(0x0100000 | DAHDI_SIG_EM)
-#define SIG_FEATD	(0x0200000 | DAHDI_SIG_EM)
-#define	SIG_FEATDMF	(0x0400000 | DAHDI_SIG_EM)
-#define	SIG_FEATB	(0x0800000 | DAHDI_SIG_EM)
-#define	SIG_E911	(0x1000000 | DAHDI_SIG_EM)
-#define	SIG_FEATDMF_TA	(0x2000000 | DAHDI_SIG_EM)
-#define	SIG_FGC_CAMA	(0x4000000 | DAHDI_SIG_EM)
-#define	SIG_FGC_CAMAMF	(0x8000000 | DAHDI_SIG_EM)
-#define SIG_FXSLS	DAHDI_SIG_FXSLS
-#define SIG_FXSGS	DAHDI_SIG_FXSGS
-#define SIG_FXSKS	DAHDI_SIG_FXSKS
-#define SIG_FXOLS	DAHDI_SIG_FXOLS
-#define SIG_FXOGS	DAHDI_SIG_FXOGS
-#define SIG_FXOKS	DAHDI_SIG_FXOKS
-#define SIG_PRI		DAHDI_SIG_CLEAR
-#define SIG_BRI		(0x2000000 | DAHDI_SIG_CLEAR)
-#define SIG_BRI_PTMP	(0X4000000 | DAHDI_SIG_CLEAR)
-#define SIG_SS7		(0x1000000 | DAHDI_SIG_CLEAR)
-#define SIG_MFCR2 	DAHDI_SIG_CAS
-#define	SIG_SF		DAHDI_SIG_SF
-#define SIG_SFWINK 	(0x0100000 | DAHDI_SIG_SF)
-#define SIG_SF_FEATD	(0x0200000 | DAHDI_SIG_SF)
-#define	SIG_SF_FEATDMF	(0x0400000 | DAHDI_SIG_SF)
-#define	SIG_SF_FEATB	(0x0800000 | DAHDI_SIG_SF)
-#define SIG_EM_E1	DAHDI_SIG_EM_E1
-
 #ifdef LOTS_OF_SPANS
 #define NUM_SPANS	DAHDI_MAX_SPANS
 #else
@@ -578,8 +547,6 @@ static int num_restart_pending = 0;
 
 static int restart_monitor(void);
 
-static enum ast_bridge_result dahdi_bridge(struct ast_channel *c0, struct ast_channel *c1, int flags, struct ast_frame **fo, struct ast_channel **rc, int timeoutms);
-
 static int dahdi_sendtext(struct ast_channel *c, const char *text);
 
 static void mwi_event_cb(void *userdata, struct stasis_subscription *sub, struct stasis_topic *topic, struct stasis_message *msg)
@@ -625,8 +592,6 @@ static inline int dahdi_wait_event(int fd)
 #define DEFAULT_RINGT 					((8000 * 8) / READ_SIZE) /*!< 8,000 ms */
 #define DEFAULT_DIALTONE_DETECT_TIMEOUT ((10000 * 8) / READ_SIZE) /*!< 10,000 ms */
 
-struct dahdi_pvt;
-
 /*!
  * \brief Configured ring timeout base.
  * \note Value computed from "ringtimeout" read in from chan_dahdi.conf if it exists.
@@ -722,644 +687,16 @@ static const char dahdi_pri_cc_type[] = "DAHDI/PRI";
 struct dahdi_pri;
 #endif
 
-#define SUB_REAL	0			/*!< Active call */
-#define SUB_CALLWAIT	1			/*!< Call-Waiting call on hold */
-#define SUB_THREEWAY	2			/*!< Three-way call */
-
 /* Polarity states */
 #define POLARITY_IDLE   0
 #define POLARITY_REV    1
 
-
-struct distRingData {
-	int ring[3];
-	int range;
-};
-struct ringContextData {
-	char contextData[AST_MAX_CONTEXT];
-};
-struct dahdi_distRings {
-	struct distRingData ringnum[3];
-	struct ringContextData ringContext[3];
-};
-
-static const char * const subnames[] = {
+const char * const subnames[] = {
 	"Real",
 	"Callwait",
 	"Threeway"
 };
 
-struct dahdi_subchannel {
-	int dfd;
-	struct ast_channel *owner;
-	int chan;
-	short buffer[AST_FRIENDLY_OFFSET/2 + READ_SIZE];
-	struct ast_frame f;		/*!< One frame for each channel.  How did this ever work before? */
-	unsigned int needringing:1;
-	unsigned int needbusy:1;
-	unsigned int needcongestion:1;
-	unsigned int needanswer:1;
-	unsigned int needflash:1;
-	unsigned int needhold:1;
-	unsigned int needunhold:1;
-	unsigned int linear:1;
-	unsigned int inthreeway:1;
-	struct dahdi_confinfo curconf;
-};
-
-#define CONF_USER_REAL		(1 << 0)
-#define CONF_USER_THIRDCALL	(1 << 1)
-
-#define MAX_SLAVES	4
-
-/* States for sending MWI message
- * First three states are required for send Ring Pulse Alert Signal
- */
-typedef enum {
-	MWI_SEND_NULL = 0,
-	MWI_SEND_SA,
-	MWI_SEND_SA_WAIT,
-	MWI_SEND_PAUSE,
-	MWI_SEND_SPILL,
-	MWI_SEND_CLEANUP,
-	MWI_SEND_DONE,
-} mwisend_states;
-
-struct mwisend_info {
-	struct	timeval	pause;
-	mwisend_states 	mwisend_current;
-};
-
-/*! Specify the lists dahdi_pvt can be put in. */
-enum DAHDI_IFLIST {
-	DAHDI_IFLIST_NONE,	/*!< The dahdi_pvt is not in any list. */
-	DAHDI_IFLIST_MAIN,	/*!< The dahdi_pvt is in the main interface list */
-#if defined(HAVE_PRI)
-	DAHDI_IFLIST_NO_B_CHAN,	/*!< The dahdi_pvt is in a no B channel interface list */
-#endif	/* defined(HAVE_PRI) */
-};
-
-struct dahdi_pvt {
-	ast_mutex_t lock;					/*!< Channel private lock. */
-	struct callerid_state *cs;
-	struct ast_channel *owner;			/*!< Our current active owner (if applicable) */
-							/*!< Up to three channels can be associated with this call */
-
-	struct dahdi_subchannel sub_unused;		/*!< Just a safety precaution */
-	struct dahdi_subchannel subs[3];			/*!< Sub-channels */
-	struct dahdi_confinfo saveconf;			/*!< Saved conference info */
-
-	struct dahdi_pvt *slaves[MAX_SLAVES];		/*!< Slave to us (follows our conferencing) */
-	struct dahdi_pvt *master;				/*!< Master to us (we follow their conferencing) */
-	int inconference;				/*!< If our real should be in the conference */
-
-	int bufsize;                /*!< Size of the buffers */
-	int buf_no;					/*!< Number of buffers */
-	int buf_policy;				/*!< Buffer policy */
-	int faxbuf_no;              /*!< Number of Fax buffers */
-	int faxbuf_policy;          /*!< Fax buffer policy */
-	int sig;					/*!< Signalling style */
-	/*!
-	 * \brief Nonzero if the signaling type is sent over a radio.
-	 * \note Set to a couple of nonzero values but it is only tested like a boolean.
-	 */
-	int radio;
-	int outsigmod;					/*!< Outbound Signalling style (modifier) */
-	int oprmode;					/*!< "Operator Services" mode */
-	struct dahdi_pvt *oprpeer;				/*!< "Operator Services" peer tech_pvt ptr */
-	/*! \brief Amount of gain to increase during caller id */
-	float cid_rxgain;
-	/*! \brief Rx gain set by chan_dahdi.conf */
-	float rxgain;
-	/*! \brief Tx gain set by chan_dahdi.conf */
-	float txgain;
-
-	float txdrc; /*!< Dynamic Range Compression factor. a number between 1 and 6ish */
-	float rxdrc;
-	
-	int tonezone;					/*!< tone zone for this chan, or -1 for default */
-	enum DAHDI_IFLIST which_iflist;	/*!< Which interface list is this structure listed? */
-	struct dahdi_pvt *next;				/*!< Next channel in list */
-	struct dahdi_pvt *prev;				/*!< Prev channel in list */
-
-	/* flags */
-
-	/*!
-	 * \brief TRUE if ADSI (Analog Display Services Interface) available
-	 * \note Set from the "adsi" value read in from chan_dahdi.conf
-	 */
-	unsigned int adsi:1;
-	/*!
-	 * \brief TRUE if we can use a polarity reversal to mark when an outgoing
-	 * call is answered by the remote party.
-	 * \note Set from the "answeronpolarityswitch" value read in from chan_dahdi.conf
-	 */
-	unsigned int answeronpolarityswitch:1;
-	/*!
-	 * \brief TRUE if busy detection is enabled.
-	 * (Listens for the beep-beep busy pattern.)
-	 * \note Set from the "busydetect" value read in from chan_dahdi.conf
-	 */
-	unsigned int busydetect:1;
-	/*!
-	 * \brief TRUE if call return is enabled.
-	 * (*69, if your dialplan doesn't catch this first)
-	 * \note Set from the "callreturn" value read in from chan_dahdi.conf
-	 */
-	unsigned int callreturn:1;
-	/*!
-	 * \brief TRUE if busy extensions will hear the call-waiting tone
-	 * and can use hook-flash to switch between callers.
-	 * \note Can be disabled by dialing *70.
-	 * \note Initialized with the "callwaiting" value read in from chan_dahdi.conf
-	 */
-	unsigned int callwaiting:1;
-	/*!
-	 * \brief TRUE if send caller ID for Call Waiting
-	 * \note Set from the "callwaitingcallerid" value read in from chan_dahdi.conf
-	 */
-	unsigned int callwaitingcallerid:1;
-	/*!
-	 * \brief TRUE if support for call forwarding enabled.
-	 * Dial *72 to enable call forwarding.
-	 * Dial *73 to disable call forwarding.
-	 * \note Set from the "cancallforward" value read in from chan_dahdi.conf
-	 */
-	unsigned int cancallforward:1;
-	/*!
-	 * \brief TRUE if support for call parking is enabled.
-	 * \note Set from the "canpark" value read in from chan_dahdi.conf
-	 */
-	unsigned int canpark:1;
-	/*! \brief TRUE if to wait for a DTMF digit to confirm answer */
-	unsigned int confirmanswer:1;
-	/*!
-	 * \brief TRUE if the channel is to be destroyed on hangup.
-	 * (Used by pseudo channels.)
-	 */
-	unsigned int destroy:1;
-	unsigned int didtdd:1;				/*!< flag to say its done it once */
-	/*! \brief TRUE if analog type line dialed no digits in Dial() */
-	unsigned int dialednone:1;
-	/*!
-	 * \brief TRUE if in the process of dialing digits or sending something.
-	 * \note This is used as a receive squelch for ISDN until connected.
-	 */
-	unsigned int dialing:1;
-	/*! \brief TRUE if the transfer capability of the call is digital. */
-	unsigned int digital:1;
-	/*! \brief TRUE if Do-Not-Disturb is enabled, present only for non sig_analog */
-	unsigned int dnd:1;
-	/*! \brief XXX BOOLEAN Purpose??? */
-	unsigned int echobreak:1;
-	/*!
-	 * \brief TRUE if echo cancellation enabled when bridged.
-	 * \note Initialized with the "echocancelwhenbridged" value read in from chan_dahdi.conf
-	 * \note Disabled if the echo canceller is not setup.
-	 */
-	unsigned int echocanbridged:1;
-	/*! \brief TRUE if echo cancellation is turned on. */
-	unsigned int echocanon:1;
-	/*! \brief TRUE if a fax tone has already been handled. */
-	unsigned int faxhandled:1;
-	/*! TRUE if dynamic faxbuffers are configured for use, default is OFF */
-	unsigned int usefaxbuffers:1;
-	/*! TRUE while buffer configuration override is in use */
-	unsigned int bufferoverrideinuse:1;
-	/*! \brief TRUE if over a radio and dahdi_read() has been called. */
-	unsigned int firstradio:1;
-	/*!
-	 * \brief TRUE if the call will be considered "hung up" on a polarity reversal.
-	 * \note Set from the "hanguponpolarityswitch" value read in from chan_dahdi.conf
-	 */
-	unsigned int hanguponpolarityswitch:1;
-	/*! \brief TRUE if DTMF detection needs to be done by hardware. */
-	unsigned int hardwaredtmf:1;
-	/*!
-	 * \brief TRUE if the outgoing caller ID is blocked/hidden.
-	 * \note Caller ID can be disabled by dialing *67.
-	 * \note Caller ID can be enabled by dialing *82.
-	 * \note Initialized with the "hidecallerid" value read in from chan_dahdi.conf
-	 */
-	unsigned int hidecallerid:1;
-	/*!
-	 * \brief TRUE if hide just the name not the number for legacy PBX use.
-	 * \note Only applies to PRI channels.
-	 * \note Set from the "hidecalleridname" value read in from chan_dahdi.conf
-	 */
-	unsigned int hidecalleridname:1;
-	/*! \brief TRUE if DTMF detection is disabled. */
-	unsigned int ignoredtmf:1;
-	/*!
-	 * \brief TRUE if the channel should be answered immediately
-	 * without attempting to gather any digits.
-	 * \note Set from the "immediate" value read in from chan_dahdi.conf
-	 */
-	unsigned int immediate:1;
-	/*! \brief TRUE if in an alarm condition. */
-	unsigned int inalarm:1;
-	/*! \brief TRUE if TDD in MATE mode */
-	unsigned int mate:1;
-	/*! \brief TRUE if we originated the call leg. */
-	unsigned int outgoing:1;
-	/* unsigned int overlapdial:1; 			unused and potentially confusing */
-	/*!
-	 * \brief TRUE if busy extensions will hear the call-waiting tone
-	 * and can use hook-flash to switch between callers.
-	 * \note Set from the "callwaiting" value read in from chan_dahdi.conf
-	 */
-	unsigned int permcallwaiting:1;
-	/*!
-	 * \brief TRUE if the outgoing caller ID is blocked/restricted/hidden.
-	 * \note Set from the "hidecallerid" value read in from chan_dahdi.conf
-	 */
-	unsigned int permhidecallerid:1;
-	/*!
-	 * \brief TRUE if PRI congestion/busy indications are sent out-of-band.
-	 * \note Set from the "priindication" value read in from chan_dahdi.conf
-	 */
-	unsigned int priindication_oob:1;
-	/*!
-	 * \brief TRUE if PRI B channels are always exclusively selected.
-	 * \note Set from the "priexclusive" value read in from chan_dahdi.conf
-	 */
-	unsigned int priexclusive:1;
-	/*!
-	 * \brief TRUE if we will pulse dial.
-	 * \note Set from the "pulsedial" value read in from chan_dahdi.conf
-	 */
-	unsigned int pulse:1;
-	/*! \brief TRUE if a pulsed digit was detected. (Pulse dial phone detected) */
-	unsigned int pulsedial:1;
-	unsigned int restartpending:1;		/*!< flag to ensure counted only once for restart */
-	/*!
-	 * \brief TRUE if caller ID is restricted.
-	 * \note Set but not used.  Should be deleted.  Redundant with permhidecallerid.
-	 * \note Set from the "restrictcid" value read in from chan_dahdi.conf
-	 */
-	unsigned int restrictcid:1;
-	/*!
-	 * \brief TRUE if three way calling is enabled
-	 * \note Set from the "threewaycalling" value read in from chan_dahdi.conf
-	 */
-	unsigned int threewaycalling:1;
-	/*!
-	 * \brief TRUE if call transfer is enabled
-	 * \note For FXS ports (either direct analog or over T1/E1):
-	 *   Support flash-hook call transfer
-	 * \note For digital ports using ISDN PRI protocols:
-	 *   Support switch-side transfer (called 2BCT, RLT or other names)
-	 * \note Set from the "transfer" value read in from chan_dahdi.conf
-	 */
-	unsigned int transfer:1;
-	/*!
-	 * \brief TRUE if caller ID is used on this channel.
-	 * \note PRI and SS7 spans will save caller ID from the networking peer.
-	 * \note FXS ports will generate the caller ID spill.
-	 * \note FXO ports will listen for the caller ID spill.
-	 * \note Set from the "usecallerid" value read in from chan_dahdi.conf
-	 */
-	unsigned int use_callerid:1;
-	/*!
-	 * \brief TRUE if we will use the calling presentation setting
-	 * from the Asterisk channel for outgoing calls.
-	 * \note Only applies to PRI and SS7 channels.
-	 * \note Set from the "usecallingpres" value read in from chan_dahdi.conf
-	 */
-	unsigned int use_callingpres:1;
-	/*!
-	 * \brief TRUE if distinctive rings are to be detected.
-	 * \note For FXO lines
-	 * \note Set indirectly from the "usedistinctiveringdetection" value read in from chan_dahdi.conf
-	 */
-	unsigned int usedistinctiveringdetection:1;
-	/*!
-	 * \brief TRUE if we should use the callerid from incoming call on dahdi transfer.
-	 * \note Set from the "useincomingcalleridondahditransfer" value read in from chan_dahdi.conf
-	 */
-	unsigned int dahditrcallerid:1;
-	/*!
-	 * \brief TRUE if allowed to flash-transfer to busy channels.
-	 * \note Set from the "transfertobusy" value read in from chan_dahdi.conf
-	 */
-	unsigned int transfertobusy:1;
-	/*!
-	 * \brief TRUE if the FXO port monitors for neon type MWI indications from the other end.
-	 * \note Set if the "mwimonitor" value read in contains "neon" from chan_dahdi.conf
-	 */
-	unsigned int mwimonitor_neon:1;
-	/*!
-	 * \brief TRUE if the FXO port monitors for fsk type MWI indications from the other end.
-	 * \note Set if the "mwimonitor" value read in contains "fsk" from chan_dahdi.conf
-	 */
-	unsigned int mwimonitor_fsk:1;
-	/*!
-	 * \brief TRUE if the FXO port monitors for rpas precursor to fsk MWI indications from the other end.
-	 * \note RPAS - Ring Pulse Alert Signal
-	 * \note Set if the "mwimonitor" value read in contains "rpas" from chan_dahdi.conf
-	 */
-	unsigned int mwimonitor_rpas:1;
-	/*! \brief TRUE if an MWI monitor thread is currently active */
-	unsigned int mwimonitoractive:1;
-	/*! \brief TRUE if a MWI message sending thread is active */
-	unsigned int mwisendactive:1;
-	/*!
-	 * \brief TRUE if channel is out of reset and ready
-	 * \note Set but not used.
-	 */
-	unsigned int inservice:1;
-	/*!
-	 * \brief TRUE if the channel is locally blocked.
-	 * \note Applies to SS7 and MFCR2 channels.
-	 */
-	unsigned int locallyblocked:1;
-	/*!
-	 * \brief TRUE if the channel is remotely blocked.
-	 * \note Applies to SS7 and MFCR2 channels.
-	 */
-	unsigned int remotelyblocked:1;
-	/*!
-	 * \brief TRUE if the channel alarms will be managed also as Span ones
-	 * \note Applies to all channels
-	 */
-	unsigned int manages_span_alarms:1;
-
-#if defined(HAVE_PRI)
-	struct sig_pri_span *pri;
-	int logicalspan;
-#endif
-	/*!
-	 * \brief TRUE if SMDI (Simplified Message Desk Interface) is enabled
-	 * \note Set from the "usesmdi" value read in from chan_dahdi.conf
-	 */
-	unsigned int use_smdi:1;
-	struct mwisend_info mwisend_data;
-	/*! \brief The SMDI interface to get SMDI messages from. */
-	struct ast_smdi_interface *smdi_iface;
-
-	/*! \brief Distinctive Ring data */
-	struct dahdi_distRings drings;
-
-	/*!
-	 * \brief The configured context for incoming calls.
-	 * \note The "context" string read in from chan_dahdi.conf
-	 */
-	char context[AST_MAX_CONTEXT];
-	/*! 
-	 * \brief A description for the channel configuration
-	 * \note The "description" string read in from chan_dahdi.conf
-	 */
-	char description[32];
-	/*!
-	 * \brief Saved context string.
-	 */
-	char defcontext[AST_MAX_CONTEXT];
-	/*! \brief Extension to use in the dialplan. */
-	char exten[AST_MAX_EXTENSION];
-	/*!
-	 * \brief Language configured for calls.
-	 * \note The "language" string read in from chan_dahdi.conf
-	 */
-	char language[MAX_LANGUAGE];
-	/*!
-	 * \brief The configured music-on-hold class to use for calls.
-	 * \note The "musicclass" or "mohinterpret" or "musiconhold" string read in from chan_dahdi.conf
-	 */
-	char mohinterpret[MAX_MUSICCLASS];
-	/*!
-	 * \brief Suggested music-on-hold class for peer channel to use for calls.
-	 * \note The "mohsuggest" string read in from chan_dahdi.conf
-	 */
-	char mohsuggest[MAX_MUSICCLASS];
-	char parkinglot[AST_MAX_EXTENSION]; /*!< Parking lot for this channel */
-#if defined(HAVE_PRI) || defined(HAVE_SS7)
-	/*! \brief Automatic Number Identification number (Alternate PRI caller ID number) */
-	char cid_ani[AST_MAX_EXTENSION];
-#endif	/* defined(HAVE_PRI) || defined(HAVE_SS7) */
-	/*! \brief Automatic Number Identification code from PRI */
-	int cid_ani2;
-	/*! \brief Caller ID number from an incoming call. */
-	char cid_num[AST_MAX_EXTENSION];
-	/*!
-	 * \brief Caller ID tag from incoming call
-	 * \note the "cid_tag" string read in from chan_dahdi.conf
-	 */
-	char cid_tag[AST_MAX_EXTENSION];
-	/*! \brief Caller ID Q.931 TON/NPI field values.  Set by PRI. Zero otherwise. */
-	int cid_ton;
-	/*! \brief Caller ID name from an incoming call. */
-	char cid_name[AST_MAX_EXTENSION];
-	/*! \brief Caller ID subaddress from an incoming call. */
-	char cid_subaddr[AST_MAX_EXTENSION];
-	char *origcid_num;				/*!< malloced original callerid */
-	char *origcid_name;				/*!< malloced original callerid */
-	/*! \brief Call waiting number. */
-	char callwait_num[AST_MAX_EXTENSION];
-	/*! \brief Call waiting name. */
-	char callwait_name[AST_MAX_EXTENSION];
-	/*! \brief Redirecting Directory Number Information Service (RDNIS) number */
-	char rdnis[AST_MAX_EXTENSION];
-	/*! \brief Dialed Number Identifier */
-	char dnid[AST_MAX_EXTENSION];
-	/*!
-	 * \brief Bitmapped groups this belongs to.
-	 * \note The "group" bitmapped group string read in from chan_dahdi.conf
-	 */
-	ast_group_t group;
-	/*! \brief Default call PCM encoding format: DAHDI_LAW_ALAW or DAHDI_LAW_MULAW. */
-	int law_default;
-	/*! \brief Active PCM encoding format: DAHDI_LAW_ALAW or DAHDI_LAW_MULAW */
-	int law;
-	int confno;					/*!< Our conference */
-	int confusers;					/*!< Who is using our conference */
-	int propconfno;					/*!< Propagated conference number */
-	/*!
-	 * \brief Bitmapped call groups this belongs to.
-	 * \note The "callgroup" bitmapped group string read in from chan_dahdi.conf
-	 */
-	ast_group_t callgroup;
-	/*!
-	 * \brief Bitmapped pickup groups this belongs to.
-	 * \note The "pickupgroup" bitmapped group string read in from chan_dahdi.conf
-	 */
-	ast_group_t pickupgroup;
-	/*!
-	 * \brief Named call groups this belongs to.
-	 * \note The "namedcallgroup" string read in from chan_dahdi.conf
-	 */
-	struct ast_namedgroups *named_callgroups;
-	/*!
-	 * \brief Named pickup groups this belongs to.
-	 * \note The "namedpickupgroup" string read in from chan_dahdi.conf
-	 */
-	struct ast_namedgroups *named_pickupgroups;
-	/*!
-	 * \brief Channel variable list with associated values to set when a channel is created.
-	 * \note The "setvar" strings read in from chan_dahdi.conf
-	 */
-	struct ast_variable *vars;
-	int channel;					/*!< Channel Number */
-	int span;					/*!< Span number */
-	time_t guardtime;				/*!< Must wait this much time before using for new call */
-	int cid_signalling;				/*!< CID signalling type bell202 or v23 */
-	int cid_start;					/*!< CID start indicator, polarity or ring or DTMF without warning event */
-	int dtmfcid_holdoff_state;		/*!< State indicator that allows for line to settle before checking for dtmf energy */
-	struct timeval	dtmfcid_delay;  /*!< Time value used for allow line to settle */
-	int callingpres;				/*!< The value of calling presentation that we're going to use when placing a PRI call */
-	int callwaitingrepeat;				/*!< How many samples to wait before repeating call waiting */
-	int cidcwexpire;				/*!< When to stop waiting for CID/CW CAS response (In samples) */
-	int cid_suppress_expire;		/*!< How many samples to suppress after a CID spill. */
-	/*! \brief Analog caller ID waveform sample buffer */
-	unsigned char *cidspill;
-	/*! \brief Position in the cidspill buffer to send out next. */
-	int cidpos;
-	/*! \brief Length of the cidspill buffer containing samples. */
-	int cidlen;
-	/*! \brief Ring timeout timer?? */
-	int ringt;
-	/*!
-	 * \brief Ring timeout base.
-	 * \note Value computed indirectly from "ringtimeout" read in from chan_dahdi.conf
-	 */
-	int ringt_base;
-	/*!
-	 * \brief Number of most significant digits/characters to strip from the dialed number.
-	 * \note Feature is deprecated.  Use dialplan logic.
-	 * \note The characters are stripped before the PRI TON/NPI prefix
-	 * characters are processed.
-	 */
-	int stripmsd;
-	/*!
-	 * \brief TRUE if Call Waiting (CW) CPE Alert Signal (CAS) is being sent.
-	 * \note
-	 * After CAS is sent, the call waiting caller id will be sent if the phone
-	 * gives a positive reply.
-	 */
-	int callwaitcas;
-	/*! \brief Number of call waiting rings. */
-	int callwaitrings;
-	/*! \brief Echo cancel parameters. */
-	struct {
-		struct dahdi_echocanparams head;
-		struct dahdi_echocanparam params[DAHDI_MAX_ECHOCANPARAMS];
-	} echocancel;
-	/*!
-	 * \brief Echo training time. 0 = disabled
-	 * \note Set from the "echotraining" value read in from chan_dahdi.conf
-	 */
-	int echotraining;
-	/*! \brief Filled with 'w'.  XXX Purpose?? */
-	char echorest[20];
-	/*!
-	 * \brief Number of times to see "busy" tone before hanging up.
-	 * \note Set from the "busycount" value read in from chan_dahdi.conf
-	 */
-	int busycount;
-	/*!
-	 * \brief Busy cadence pattern description.
-	 * \note Set from the "busypattern" value read from chan_dahdi.conf
-	 */
-	struct ast_dsp_busy_pattern busy_cadence;
-	/*!
-	 * \brief Bitmapped call progress detection flags. CALLPROGRESS_xxx values.
-	 * \note Bits set from the "callprogress" and "faxdetect" values read in from chan_dahdi.conf
-	 */
-	int callprogress;
-	/*!
-	 * \brief Number of milliseconds to wait for dialtone.
-	 * \note Set from the "waitfordialtone" value read in from chan_dahdi.conf
-	 */
-	int waitfordialtone;
-	/*!
-	 * \brief Number of frames to watch for dialtone in incoming calls
-	 * \note Set from the "dialtone_detect" value read in from chan_dahdi.conf
-	 */
-	int dialtone_detect;
-	int dialtone_scanning_time_elapsed;	/*!< Amount of audio scanned for dialtone, in frames */
-	struct timeval waitingfordt;			/*!< Time we started waiting for dialtone */
-	struct timeval flashtime;			/*!< Last flash-hook time */
-	/*! \brief Opaque DSP configuration structure. */
-	struct ast_dsp *dsp;
-	/*! \brief DAHDI dial operation command struct for ioctl() call. */
-	struct dahdi_dialoperation dop;
-	int whichwink;					/*!< SIG_FEATDMF_TA Which wink are we on? */
-	/*! \brief Second part of SIG_FEATDMF_TA wink operation. */
-	char finaldial[64];
-	char accountcode[AST_MAX_ACCOUNT_CODE];		/*!< Account code */
-	int amaflags;					/*!< AMA Flags */
-	struct tdd_state *tdd;				/*!< TDD flag */
-	/*! \brief Accumulated call forwarding number. */
-	char call_forward[AST_MAX_EXTENSION];
-	/*!
-	 * \brief Voice mailbox location.
-	 * \note Set from the "mailbox" string read in from chan_dahdi.conf
-	 */
-	char mailbox[AST_MAX_EXTENSION];
-	/*! \brief Opaque event subscription parameters for message waiting indication support. */
-	struct stasis_subscription *mwi_event_sub;
-	/*! \brief Delayed dialing for E911.  Overlap digits for ISDN. */
-	char dialdest[256];
-#ifdef HAVE_DAHDI_LINEREVERSE_VMWI
-	struct dahdi_vmwi_info mwisend_setting;				/*!< Which VMWI methods to use */
-	unsigned int mwisend_fsk: 1;		/*! Variable for enabling FSK MWI handling in chan_dahdi */
-	unsigned int mwisend_rpas:1;		/*! Variable for enabling Ring Pulse Alert before MWI FSK Spill */
-#endif
-	int distinctivering;				/*!< Which distinctivering to use */
-	int dtmfrelax;					/*!< whether to run in relaxed DTMF mode */
-	/*! \brief Holding place for event injected from outside normal operation. */
-	int fake_event;
-	/*!
-	 * \brief Minimal time period (ms) between the answer polarity
-	 * switch and hangup polarity switch.
-	 */
-	int polarityonanswerdelay;
-	/*! \brief Start delay time if polarityonanswerdelay is nonzero. */
-	struct timeval polaritydelaytv;
-	/*!
-	 * \brief Send caller ID on FXS after this many rings. Set to 1 for US.
-	 * \note Set from the "sendcalleridafter" value read in from chan_dahdi.conf
-	 */
-	int sendcalleridafter;
-	/*! \brief Current line interface polarity. POLARITY_IDLE, POLARITY_REV */
-	int polarity;
-	/*! \brief DSP feature flags: DSP_FEATURE_xxx */
-	int dsp_features;
-#if defined(HAVE_SS7)
-	/*! \brief SS7 control parameters */
-	struct sig_ss7_linkset *ss7;
-#endif	/* defined(HAVE_SS7) */
-#ifdef HAVE_OPENR2
-	struct dahdi_mfcr2 *mfcr2;
-	openr2_chan_t *r2chan;
-	openr2_calling_party_category_t mfcr2_recvd_category;
-	openr2_calling_party_category_t mfcr2_category;
-	int mfcr2_dnis_index;
-	int mfcr2_ani_index;
-	int mfcr2call:1;
-	int mfcr2_answer_pending:1;
-	int mfcr2_charge_calls:1;
-	int mfcr2_allow_collect_calls:1;
-	int mfcr2_forced_release:1;
-	int mfcr2_dnis_matched:1;
-	int mfcr2_call_accepted:1;
-	int mfcr2_accept_on_offer:1;
-	int mfcr2_progress_sent:1;
-#endif
-	/*! \brief DTMF digit in progress.  0 when no digit in progress. */
-	char begindigit;
-	/*! \brief TRUE if confrence is muted. */
-	int muting;
-	void *sig_pvt;
-	struct ast_cc_config_params *cc_params;
-	/* DAHDI channel names may differ greatly from the
-	 * string that was provided to an app such as Dial. We
-	 * need to save the original string passed to dahdi_request
-	 * for call completion purposes. This way, we can replicate
-	 * the original dialed string later.
-	 */
-	char dialstring[AST_CHANNEL_NAME];
-};
-
 #define DATA_EXPORT_DAHDI_PVT(MEMBER)					\
 	MEMBER(dahdi_pvt, cid_rxgain, AST_DATA_DOUBLE)			\
 	MEMBER(dahdi_pvt, rxgain, AST_DATA_DOUBLE)			\
@@ -1634,8 +971,6 @@ static int dahdi_func_write(struct ast_channel *chan, const char *function, char
 static int dahdi_devicestate(const char *data);
 static int dahdi_cc_callback(struct ast_channel *inbound, const char *dest, ast_cc_callback_fn callback);
 
-/* BUGBUG The DAHDI channel driver needs its own native bridge technology. */
-/* BUGBUG The transfer=yes option is broken for ISDN to push tromboned calls to the peer. */
 static struct ast_channel_tech dahdi_tech = {
 	.type = "DAHDI",
 	.description = tdesc,
@@ -1648,7 +983,6 @@ static struct ast_channel_tech dahdi_tech = {
 	.answer = dahdi_answer,
 	.read = dahdi_read,
 	.write = dahdi_write,
-	.bridge = dahdi_bridge,
 	.exception = dahdi_exception,
 	.indicate = dahdi_indicate,
 	.fixup = dahdi_fixup,
@@ -1662,77 +996,6 @@ static struct ast_channel_tech dahdi_tech = {
 
 #define GET_CHANNEL(p) ((p)->channel)
 
-#define SIG_PRI_LIB_HANDLE_CASES	\
-	SIG_PRI:						\
-	case SIG_BRI:					\
-	case SIG_BRI_PTMP
-
-/*!
- * \internal
- * \brief Determine if sig_pri handles the signaling.
- * \since 1.8
- *
- * \param signaling Signaling to determine if is for sig_pri.
- *
- * \return TRUE if the signaling is for sig_pri.
- */
-static inline int dahdi_sig_pri_lib_handles(int signaling)
-{
-	int handles;
-
-	switch (signaling) {
-	case SIG_PRI_LIB_HANDLE_CASES:
-		handles = 1;
-		break;
-	default:
-		handles = 0;
-		break;
-	}
-
-	return handles;
-}
-
-static int analog_lib_handles(int signalling, int radio, int oprmode)
-{
-	switch (signalling) {
-	case SIG_FXOLS:
-	case SIG_FXOGS:
-	case SIG_FXOKS:
-	case SIG_FXSLS:
-	case SIG_FXSGS:
-	case SIG_FXSKS:
-	case SIG_EMWINK:
-	case SIG_EM:
-	case SIG_EM_E1:
-	case SIG_FEATD:
-	case SIG_FEATDMF:
-	case SIG_E911:
-	case SIG_FGC_CAMA:
-	case SIG_FGC_CAMAMF:
-	case SIG_FEATB:
-	case SIG_SFWINK:
-	case SIG_SF:
-	case SIG_SF_FEATD:
-	case SIG_SF_FEATDMF:
-	case SIG_FEATDMF_TA:
-	case SIG_SF_FEATB:
-		break;
-	default:
-		/* The rest of the function should cover the remainder of signalling types */
-		return 0;
-	}
-
-	if (radio) {
-		return 0;
-	}
-
-	if (oprmode) {
-		return 0;
-	}
-
-	return 1;
-}
-
 static enum analog_sigtype dahdisig_to_analogsig(int sig)
 {
 	switch (sig) {
@@ -3161,9 +2424,6 @@ static int my_is_off_hook(void *pvt)
 	return par.rxisoffhook;
 }
 
-static void dahdi_enable_ec(struct dahdi_pvt *p);
-static void dahdi_disable_ec(struct dahdi_pvt *p);
-
 static int my_set_echocanceller(void *pvt, int enable)
 {
 	struct dahdi_pvt *p = pvt;
@@ -3996,8 +3256,7 @@ struct analog_callback analog_callbacks =
 /*! Round robin search locations. */
 static struct dahdi_pvt *round_robin[32];
 
-#define dahdi_get_index(ast, p, nullok)	_dahdi_get_index(ast, p, nullok, __PRETTY_FUNCTION__, __LINE__)
-static int _dahdi_get_index(struct ast_channel *ast, struct dahdi_pvt *p, int nullok, const char *fname, unsigned long line)
+int _dahdi_get_index(struct ast_channel *ast, struct dahdi_pvt *p, int nullok, const char *fname, unsigned long line)
 {
 	int res;
 	if (p->subs[SUB_REAL].owner == ast)
@@ -4312,7 +3571,6 @@ static void dahdi_r2_on_call_end(openr2_chan_t *r2chan)
 	ast_mutex_unlock(&p->lock);
 }
 
-static void dahdi_enable_ec(struct dahdi_pvt *p);
 static void dahdi_r2_on_call_accepted(openr2_chan_t *r2chan, openr2_call_mode_t mode)
 {
 	struct dahdi_pvt *p = NULL;
@@ -5106,7 +4364,7 @@ static int reset_conf(struct dahdi_pvt *p)
 	return 0;
 }
 
-static int update_conf(struct dahdi_pvt *p)
+void update_conf(struct dahdi_pvt *p)
 {
 	int needconf = 0;
 	int x;
@@ -5159,10 +4417,9 @@ static int update_conf(struct dahdi_pvt *p)
 		p->confno = -1;
 	}
 	ast_debug(1, "Updated conferencing on %d, with %d conference users\n", p->channel, needconf);
-	return 0;
 }
 
-static void dahdi_enable_ec(struct dahdi_pvt *p)
+void dahdi_enable_ec(struct dahdi_pvt *p)
 {
 	int res;
 	if (!p)
@@ -5234,7 +4491,7 @@ static void dahdi_train_ec(struct dahdi_pvt *p)
 	}
 }
 
-static void dahdi_disable_ec(struct dahdi_pvt *p)
+void dahdi_disable_ec(struct dahdi_pvt *p)
 {
 	int res;
 
@@ -6954,7 +6211,7 @@ static int dahdi_answer(struct ast_channel *ast)
 	return res;
 }
 
-static void disable_dtmf_detect(struct dahdi_pvt *p)
+void disable_dtmf_detect(struct dahdi_pvt *p)
 {
 	int val = 0;
 
@@ -6968,7 +6225,7 @@ static void disable_dtmf_detect(struct dahdi_pvt *p)
 	}
 }
 
-static void enable_dtmf_detect(struct dahdi_pvt *p)
+void enable_dtmf_detect(struct dahdi_pvt *p)
 {
 	int val = DAHDI_TONEDETECT_ON | DAHDI_TONEDETECT_MUTE;
 
@@ -7458,7 +6715,7 @@ static int dahdi_func_write(struct ast_channel *chan, const char *function, char
 	return res;
 }
 
-static void dahdi_unlink(struct dahdi_pvt *slave, struct dahdi_pvt *master, int needlock)
+void dahdi_unlink(struct dahdi_pvt *slave, struct dahdi_pvt *master, int needlock)
 {
 	/* Unlink a specific slave or all slaves/masters from a given master */
 	int x;
@@ -7514,7 +6771,8 @@ static void dahdi_unlink(struct dahdi_pvt *slave, struct dahdi_pvt *master, int
 	}
 }
 
-static void dahdi_link(struct dahdi_pvt *slave, struct dahdi_pvt *master) {
+void dahdi_link(struct dahdi_pvt *slave, struct dahdi_pvt *master)
+{
 	int x;
 	if (!slave || !master) {
 		ast_log(LOG_WARNING, "Tried to link to/from NULL??\n");
@@ -7537,373 +6795,6 @@ static void dahdi_link(struct dahdi_pvt *slave, struct dahdi_pvt *master) {
 	ast_debug(1, "Making %d slave to master %d at %d\n", slave->channel, master->channel, x);
 }
 
-static enum ast_bridge_result dahdi_bridge(struct ast_channel *c0, struct ast_channel *c1, int flags, struct ast_frame **fo, struct ast_channel **rc, int timeoutms)
-{
-	struct ast_channel *who;
-	struct dahdi_pvt *p0, *p1, *op0, *op1;
-	struct dahdi_pvt *master = NULL, *slave = NULL;
-	struct ast_frame *f;
-	int inconf = 0;
-	int nothingok = 1;
-	int ofd0, ofd1;
-	int oi0, oi1, i0 = -1, i1 = -1, t0, t1;
-	int os0 = -1, os1 = -1;
-	int priority = 0;
-	struct ast_channel *oc0, *oc1;
-	enum ast_bridge_result res;
-	struct timeval start = ast_tvnow();
-#ifdef PRI_2BCT
-	int triedtopribridge = 0;
-	q931_call *q931c0;
-	q931_call *q931c1;
-#endif
-
-	/* For now, don't attempt to native bridge if either channel needs DTMF detection.
-	   There is code below to handle it properly until DTMF is actually seen,
-	   but due to currently unresolved issues it's ignored...
-	*/
-
-	if (flags & (AST_BRIDGE_DTMF_CHANNEL_0 | AST_BRIDGE_DTMF_CHANNEL_1))
-		return AST_BRIDGE_FAILED_NOWARN;
-
-	ast_channel_lock_both(c0, c1);
-
-	p0 = ast_channel_tech_pvt(c0);
-	p1 = ast_channel_tech_pvt(c1);
-	/* cant do pseudo-channels here */
-	if (!p0 || (!p0->sig) || !p1 || (!p1->sig)) {
-		ast_channel_unlock(c0);
-		ast_channel_unlock(c1);
-		return AST_BRIDGE_FAILED_NOWARN;
-	}
-
-	oi0 = dahdi_get_index(c0, p0, 0);
-	oi1 = dahdi_get_index(c1, p1, 0);
-	if ((oi0 < 0) || (oi1 < 0)) {
-		ast_channel_unlock(c0);
-		ast_channel_unlock(c1);
-		return AST_BRIDGE_FAILED;
-	}
-
-	op0 = p0 = ast_channel_tech_pvt(c0);
-	op1 = p1 = ast_channel_tech_pvt(c1);
-	ofd0 = ast_channel_fd(c0, 0);
-	ofd1 = ast_channel_fd(c1, 0);
-	oc0 = p0->owner;
-	oc1 = p1->owner;
-
-	if (ast_mutex_trylock(&p0->lock)) {
-		/* Don't block, due to potential for deadlock */
-		ast_channel_unlock(c0);
-		ast_channel_unlock(c1);
-		ast_log(LOG_NOTICE, "Avoiding deadlock...\n");
-		return AST_BRIDGE_RETRY;
-	}
-	if (ast_mutex_trylock(&p1->lock)) {
-		/* Don't block, due to potential for deadlock */
-		ast_mutex_unlock(&p0->lock);
-		ast_channel_unlock(c0);
-		ast_channel_unlock(c1);
-		ast_log(LOG_NOTICE, "Avoiding deadlock...\n");
-		return AST_BRIDGE_RETRY;
-	}
-
-	if ((p0->callwaiting && p0->callwaitingcallerid)
-		|| (p1->callwaiting && p1->callwaitingcallerid)) {
-		/*
-		 * Call Waiting Caller ID requires DTMF detection to know if it
-		 * can send the CID spill.
-		 *
-		 * For now, don't attempt to native bridge if either channel
-		 * needs DTMF detection.  There is code below to handle it
-		 * properly until DTMF is actually seen, but due to currently
-		 * unresolved issues it's ignored...
-		 */
-		ast_mutex_unlock(&p0->lock);
-		ast_mutex_unlock(&p1->lock);
-		ast_channel_unlock(c0);
-		ast_channel_unlock(c1);
-		return AST_BRIDGE_FAILED_NOWARN;
-	}
-
-#if defined(HAVE_PRI)
-	if ((dahdi_sig_pri_lib_handles(p0->sig)
-			&& ((struct sig_pri_chan *) p0->sig_pvt)->no_b_channel)
-		|| (dahdi_sig_pri_lib_handles(p1->sig)
-			&& ((struct sig_pri_chan *) p1->sig_pvt)->no_b_channel)) {
-		/*
-		 * PRI nobch channels (hold and call waiting) are equivalent to
-		 * pseudo channels and cannot be done here.
-		 */
-		ast_mutex_unlock(&p0->lock);
-		ast_mutex_unlock(&p1->lock);
-		ast_channel_unlock(c0);
-		ast_channel_unlock(c1);
-		return AST_BRIDGE_FAILED_NOWARN;
-	}
-#endif	/* defined(HAVE_PRI) */
-
-	if ((oi0 == SUB_REAL) && (oi1 == SUB_REAL)) {
-		if (p0->owner && p1->owner) {
-			/* If we don't have a call-wait in a 3-way, and we aren't in a 3-way, we can be master */
-			if (!p0->subs[SUB_CALLWAIT].inthreeway && !p1->subs[SUB_REAL].inthreeway) {
-				master = p0;
-				slave = p1;
-				inconf = 1;
-			} else if (!p1->subs[SUB_CALLWAIT].inthreeway && !p0->subs[SUB_REAL].inthreeway) {
-				master = p1;
-				slave = p0;
-				inconf = 1;
-			} else {
-				ast_log(LOG_WARNING, "Huh?  Both calls are callwaits or 3-ways?  That's clever...?\n");
-				ast_log(LOG_WARNING, "p0: chan %d/%d/CW%d/3W%d, p1: chan %d/%d/CW%d/3W%d\n",
-					p0->channel,
-					oi0, (p0->subs[SUB_CALLWAIT].dfd > -1) ? 1 : 0,
-					p0->subs[SUB_REAL].inthreeway, p0->channel,
-					oi0, (p1->subs[SUB_CALLWAIT].dfd > -1) ? 1 : 0,
-					p1->subs[SUB_REAL].inthreeway);
-			}
-			nothingok = 0;
-		}
-	} else if ((oi0 == SUB_REAL) && (oi1 == SUB_THREEWAY)) {
-		if (p1->subs[SUB_THREEWAY].inthreeway) {
-			master = p1;
-			slave = p0;
-			nothingok = 0;
-		}
-	} else if ((oi0 == SUB_THREEWAY) && (oi1 == SUB_REAL)) {
-		if (p0->subs[SUB_THREEWAY].inthreeway) {
-			master = p0;
-			slave = p1;
-			nothingok = 0;
-		}
-	} else if ((oi0 == SUB_REAL) && (oi1 == SUB_CALLWAIT)) {
-		/* We have a real and a call wait.  If we're in a three way call, put us in it, otherwise,
-		   don't put us in anything */
-		if (p1->subs[SUB_CALLWAIT].inthreeway) {
-			master = p1;
-			slave = p0;
-			nothingok = 0;
-		}
-	} else if ((oi0 == SUB_CALLWAIT) && (oi1 == SUB_REAL)) {
-		/* Same as previous */
-		if (p0->subs[SUB_CALLWAIT].inthreeway) {
-			master = p0;
-			slave = p1;
-			nothingok = 0;
-		}
-	}
-	ast_debug(1, "master: %d, slave: %d, nothingok: %d\n",
-		master ? master->channel : 0, slave ? slave->channel : 0, nothingok);
-	if (master && slave) {
-		/* Stop any tones, or play ringtone as appropriate.  If they're bridged
-		   in an active threeway call with a channel that is ringing, we should
-		   indicate ringing. */
-		if ((oi1 == SUB_THREEWAY) &&
-			p1->subs[SUB_THREEWAY].inthreeway &&
-			p1->subs[SUB_REAL].owner &&
-			p1->subs[SUB_REAL].inthreeway &&
-			(ast_channel_state(p1->subs[SUB_REAL].owner) == AST_STATE_RINGING)) {
-			ast_debug(1,
-				"Playing ringback on %d/%d(%s) since %d/%d(%s) is in a ringing three-way\n",
-				p0->channel, oi0, ast_channel_name(c0), p1->channel, oi1, ast_channel_name(c1));
-			tone_zone_play_tone(p0->subs[oi0].dfd, DAHDI_TONE_RINGTONE);
-			os1 = ast_channel_state(p1->subs[SUB_REAL].owner);
-		} else {
-			ast_debug(1, "Stopping tones on %d/%d(%s) talking to %d/%d(%s)\n",
-				p0->channel, oi0, ast_channel_name(c0), p1->channel, oi1, ast_channel_name(c1));
-			tone_zone_play_tone(p0->subs[oi0].dfd, -1);
-		}
-		if ((oi0 == SUB_THREEWAY) &&
-			p0->subs[SUB_THREEWAY].inthreeway &&
-			p0->subs[SUB_REAL].owner &&
-			p0->subs[SUB_REAL].inthreeway &&
-			(ast_channel_state(p0->subs[SUB_REAL].owner) == AST_STATE_RINGING)) {
-			ast_debug(1,
-				"Playing ringback on %d/%d(%s) since %d/%d(%s) is in a ringing three-way\n",
-				p1->channel, oi1, ast_channel_name(c1), p0->channel, oi0, ast_channel_name(c0));
-			tone_zone_play_tone(p1->subs[oi1].dfd, DAHDI_TONE_RINGTONE);
-			os0 = ast_channel_state(p0->subs[SUB_REAL].owner);
-		} else {
-			ast_debug(1, "Stopping tones on %d/%d(%s) talking to %d/%d(%s)\n",
-				p1->channel, oi1, ast_channel_name(c1), p0->channel, oi0, ast_channel_name(c0));
-			tone_zone_play_tone(p1->subs[oi1].dfd, -1);
-		}
-		if ((oi0 == SUB_REAL) && (oi1 == SUB_REAL)) {
-			if (!p0->echocanbridged || !p1->echocanbridged) {
-				/* Disable echo cancellation if appropriate */
-				dahdi_disable_ec(p0);
-				dahdi_disable_ec(p1);
-			}
-		}
-		dahdi_link(slave, master);
-		master->inconference = inconf;
-	} else if (!nothingok)
-		ast_log(LOG_WARNING, "Can't link %d/%s with %d/%s\n", p0->channel, subnames[oi0], p1->channel, subnames[oi1]);
-
-	update_conf(p0);
-	update_conf(p1);
-	t0 = p0->subs[SUB_REAL].inthreeway;
-	t1 = p1->subs[SUB_REAL].inthreeway;
-
-	ast_mutex_unlock(&p0->lock);
-	ast_mutex_unlock(&p1->lock);
-
-	ast_channel_unlock(c0);
-	ast_channel_unlock(c1);
-
-	/* Native bridge failed */
-	if ((!master || !slave) && !nothingok) {
-		dahdi_enable_ec(p0);
-		dahdi_enable_ec(p1);
-		return AST_BRIDGE_FAILED;
-	}
-
-	ast_verb(3, "Native bridging %s and %s\n", ast_channel_name(c0), ast_channel_name(c1));
-
-	if (!(flags & AST_BRIDGE_DTMF_CHANNEL_0) && (oi0 == SUB_REAL))
-		disable_dtmf_detect(op0);
-
-	if (!(flags & AST_BRIDGE_DTMF_CHANNEL_1) && (oi1 == SUB_REAL))
-		disable_dtmf_detect(op1);
-
-	for (;;) {
-		struct ast_channel *c0_priority[2] = {c0, c1};
-		struct ast_channel *c1_priority[2] = {c1, c0};
-		int ms;
-
-		/* Here's our main loop...  Start by locking things, looking for private parts,
-		   and then balking if anything is wrong */
-
-		ast_channel_lock_both(c0, c1);
-
-		p0 = ast_channel_tech_pvt(c0);
-		p1 = ast_channel_tech_pvt(c1);
-
-		if (op0 == p0)
-			i0 = dahdi_get_index(c0, p0, 1);
-		if (op1 == p1)
-			i1 = dahdi_get_index(c1, p1, 1);
-
-		ast_channel_unlock(c0);
-		ast_channel_unlock(c1);
-		ms = ast_remaining_ms(start, timeoutms);
-		if (!ms ||
-			(op0 != p0) ||
-			(op1 != p1) ||
-			(ofd0 != ast_channel_fd(c0, 0)) ||
-			(ofd1 != ast_channel_fd(c1, 0)) ||
-			(p0->subs[SUB_REAL].owner && (os0 > -1) && (os0 != ast_channel_state(p0->subs[SUB_REAL].owner))) ||
-			(p1->subs[SUB_REAL].owner && (os1 > -1) && (os1 != ast_channel_state(p1->subs[SUB_REAL].owner))) ||
-			(oc0 != p0->owner) ||
-			(oc1 != p1->owner) ||
-			(t0 != p0->subs[SUB_REAL].inthreeway) ||
-			(t1 != p1->subs[SUB_REAL].inthreeway) ||
-			(oi0 != i0) ||
-			(oi1 != i1)) {
-			ast_debug(1, "Something changed out on %d/%d to %d/%d, returning -3 to restart\n",
-				op0->channel, oi0, op1->channel, oi1);
-			res = AST_BRIDGE_RETRY;
-			goto return_from_bridge;
-		}
-
-#ifdef PRI_2BCT
-		if (!triedtopribridge) {
-			triedtopribridge = 1;
-			if (p0->pri && p0->pri == p1->pri && p0->pri->transfer) {
-				ast_mutex_lock(&p0->pri->lock);
-				switch (p0->sig) {
-				case SIG_PRI_LIB_HANDLE_CASES:
-					q931c0 = ((struct sig_pri_chan *) (p0->sig_pvt))->call;
-					break;
-				default:
-					q931c0 = NULL;
-					break;
-				}
-				switch (p1->sig) {
-				case SIG_PRI_LIB_HANDLE_CASES:
-					q931c1 = ((struct sig_pri_chan *) (p1->sig_pvt))->call;
-					break;
-				default:
-					q931c1 = NULL;
-					break;
-				}
-				if (q931c0 && q931c1) {
-					pri_channel_bridge(q931c0, q931c1);
-				}
-				ast_mutex_unlock(&p0->pri->lock);
-			}
-		}
-#endif
-
-		who = ast_waitfor_n(priority ? c0_priority : c1_priority, 2, &ms);
-		if (!who) {
-			ast_debug(1, "Ooh, empty read...\n");
-			continue;
-		}
-		f = ast_read(who);
-		switch (f ? f->frametype : AST_FRAME_CONTROL) {
-		case AST_FRAME_CONTROL:
-			if (f && f->subclass.integer == AST_CONTROL_PVT_CAUSE_CODE) {
-				ast_channel_hangupcause_hash_set((who == c0) ? c1 : c0, f->data.ptr, f->datalen);
-				break;
-			}
-			*fo = f;
-			*rc = who;
-			res = AST_BRIDGE_COMPLETE;
-			goto return_from_bridge;
-		case AST_FRAME_DTMF_END:
-			if ((who == c0) && p0->pulsedial) {
-				ast_write(c1, f);
-			} else if ((who == c1) && p1->pulsedial) {
-				ast_write(c0, f);
-			} else {
-				*fo = f;
-				*rc = who;
-				res = AST_BRIDGE_COMPLETE;
-				goto return_from_bridge;
-			}
-			break;
-		case AST_FRAME_TEXT:
-			if (who == c0) {
-				ast_write(c1, f);
-			} else {
-				ast_write(c0, f);
-			}
-			break;
-		case AST_FRAME_VOICE:
-			/* Native bridge handles voice frames in hardware. */
-		case AST_FRAME_NULL:
-			break;
-		default:
-			ast_debug(1, "Chan '%s' is discarding frame of frametype:%d\n",
-				ast_channel_name(who), f->frametype);
-			break;
-		}
-		ast_frfree(f);
-
-		/* Swap who gets priority */
-		priority = !priority;
-	}
-
-return_from_bridge:
-	if (op0 == p0)
-		dahdi_enable_ec(p0);
-
-	if (op1 == p1)
-		dahdi_enable_ec(p1);
-
-	if (!(flags & AST_BRIDGE_DTMF_CHANNEL_0) && (oi0 == SUB_REAL))
-		enable_dtmf_detect(op0);
-
-	if (!(flags & AST_BRIDGE_DTMF_CHANNEL_1) && (oi1 == SUB_REAL))
-		enable_dtmf_detect(op1);
-
-	dahdi_unlink(slave, master, 1);
-
-	return res;
-}
-
 static int dahdi_fixup(struct ast_channel *oldchan, struct ast_channel *newchan)
 {
 	struct dahdi_pvt *p = ast_channel_tech_pvt(newchan);
@@ -17407,6 +16298,8 @@ static int __unload_module(void)
 #endif	/* defined(HAVE_SS7) */
 	ast_cond_destroy(&ss_thread_complete);
 
+	dahdi_native_unload();
+
 	dahdi_tech.capabilities = ast_format_cap_destroy(dahdi_tech.capabilities);
 	STASIS_MESSAGE_TYPE_CLEANUP(dahdichannel_type);
 	return 0;
@@ -19420,6 +18313,10 @@ static int load_module(void)
 	ast_format_cap_add(dahdi_tech.capabilities, ast_format_set(&tmpfmt, AST_FORMAT_ULAW, 0));
 	ast_format_cap_add(dahdi_tech.capabilities, ast_format_set(&tmpfmt, AST_FORMAT_ALAW, 0));
 
+	if (dahdi_native_load(ast_module_info->self, &dahdi_tech)) {
+		return AST_MODULE_LOAD_FAILURE;
+	}
+
 #ifdef HAVE_PRI
 	memset(pris, 0, sizeof(pris));
 	for (y = 0; y < NUM_SPANS; y++) {
@@ -19640,5 +18537,5 @@ AST_MODULE_INFO(ASTERISK_GPL_KEY, AST_MODFLAG_LOAD_ORDER, tdesc,
 	.unload = unload_module,
 	.reload = reload,
 	.load_pri = AST_MODPRI_CHANNEL_DRIVER,
-		.nonoptreq = "res_smdi",
+	.nonoptreq = "res_smdi",
 	);
diff --git a/channels/chan_dahdi.h b/channels/chan_dahdi.h
new file mode 100644
index 000000000..69c20db2c
--- /dev/null
+++ b/channels/chan_dahdi.h
@@ -0,0 +1,808 @@
+/*
+ * Asterisk -- An open source telephony toolkit.
+ *
+ * Copyright (C) 2013 Digium, Inc.
+ *
+ * Richard Mudgett <rmudgett@digium.com>
+ *
+ * See http://www.asterisk.org for more information about
+ * the Asterisk project. Please do not directly contact
+ * any of the maintainers of this project for assistance;
+ * the project provides a web site, mailing lists and IRC
+ * channels for your use.
+ *
+ * This program is free software, distributed under the terms of
+ * the GNU General Public License Version 2. See the LICENSE file
+ * at the top of the source tree.
+ */
+
+/*!
+ * \file
+ * \brief DAHDI internal API definitions.
+ *
+ * \author Richard Mudgett <rmudgett@digium.com>
+ *
+ * See Also:
+ * \arg \ref AstCREDITS
+ */
+
+#ifndef _ASTERISK_CHAN_DAHDI_H
+#define _ASTERISK_CHAN_DAHDI_H
+
+#if defined(HAVE_OPENR2)
+#include <openr2.h>
+#endif	/* defined(HAVE_OPENR2) */
+
+#include <dahdi/user.h>
+#include <dahdi/tonezone.h>
+
+#include "asterisk/channel.h"
+#include "asterisk/dsp.h"
+
+#if defined(__cplusplus) || defined(c_plusplus)
+extern "C" {
+#endif
+
+/* ------------------------------------------------------------------- */
+
+#if defined(HAVE_PRI)
+struct sig_pri_span;
+#endif	/* defined(HAVE_PRI) */
+#if defined(HAVE_SS7)
+struct sig_ss7_linkset;
+#endif	/* defined(HAVE_SS7) */
+
+#define SUB_REAL		0			/*!< Active call */
+#define SUB_CALLWAIT	1			/*!< Call-Waiting call on hold */
+#define SUB_THREEWAY	2			/*!< Three-way call */
+
+
+struct distRingData {
+	int ring[3];
+	int range;
+};
+struct ringContextData {
+	char contextData[AST_MAX_CONTEXT];
+};
+struct dahdi_distRings {
+	struct distRingData ringnum[3];
+	struct ringContextData ringContext[3];
+};
+
+
+extern const char * const subnames[];
+
+struct dahdi_subchannel {
+	int dfd;
+	struct ast_channel *owner;
+	int chan;
+	short buffer[AST_FRIENDLY_OFFSET/2 + READ_SIZE];
+	struct ast_frame f;		/*!< One frame for each channel.  How did this ever work before? */
+	unsigned int needringing:1;
+	unsigned int needbusy:1;
+	unsigned int needcongestion:1;
+	unsigned int needanswer:1;
+	unsigned int needflash:1;
+	unsigned int needhold:1;
+	unsigned int needunhold:1;
+	unsigned int linear:1;
+	unsigned int inthreeway:1;
+	struct dahdi_confinfo curconf;
+};
+
+#define MAX_SLAVES	4
+
+/* States for sending MWI message
+ * First three states are required for send Ring Pulse Alert Signal
+ */
+typedef enum {
+	MWI_SEND_NULL = 0,
+	MWI_SEND_SA,
+	MWI_SEND_SA_WAIT,
+	MWI_SEND_PAUSE,
+	MWI_SEND_SPILL,
+	MWI_SEND_CLEANUP,
+	MWI_SEND_DONE,
+} mwisend_states;
+
+struct mwisend_info {
+	struct timeval pause;
+	mwisend_states mwisend_current;
+};
+
+/*! Specify the lists dahdi_pvt can be put in. */
+enum DAHDI_IFLIST {
+	DAHDI_IFLIST_NONE,	/*!< The dahdi_pvt is not in any list. */
+	DAHDI_IFLIST_MAIN,	/*!< The dahdi_pvt is in the main interface list */
+#if defined(HAVE_PRI)
+	DAHDI_IFLIST_NO_B_CHAN,	/*!< The dahdi_pvt is in a no B channel interface list */
+#endif	/* defined(HAVE_PRI) */
+};
+
+struct dahdi_pvt {
+	ast_mutex_t lock;					/*!< Channel private lock. */
+	struct callerid_state *cs;
+	struct ast_channel *owner;			/*!< Our current active owner (if applicable) */
+							/*!< Up to three channels can be associated with this call */
+
+	struct dahdi_subchannel sub_unused;		/*!< Just a safety precaution */
+	struct dahdi_subchannel subs[3];			/*!< Sub-channels */
+	struct dahdi_confinfo saveconf;			/*!< Saved conference info */
+
+	struct dahdi_pvt *slaves[MAX_SLAVES];		/*!< Slave to us (follows our conferencing) */
+	struct dahdi_pvt *master;				/*!< Master to us (we follow their conferencing) */
+	int inconference;				/*!< If our real should be in the conference */
+
+	int bufsize;                /*!< Size of the buffers */
+	int buf_no;					/*!< Number of buffers */
+	int buf_policy;				/*!< Buffer policy */
+	int faxbuf_no;              /*!< Number of Fax buffers */
+	int faxbuf_policy;          /*!< Fax buffer policy */
+	int sig;					/*!< Signalling style */
+	/*!
+	 * \brief Nonzero if the signaling type is sent over a radio.
+	 * \note Set to a couple of nonzero values but it is only tested like a boolean.
+	 */
+	int radio;
+	int outsigmod;					/*!< Outbound Signalling style (modifier) */
+	int oprmode;					/*!< "Operator Services" mode */
+	struct dahdi_pvt *oprpeer;				/*!< "Operator Services" peer tech_pvt ptr */
+	/*! \brief Amount of gain to increase during caller id */
+	float cid_rxgain;
+	/*! \brief Rx gain set by chan_dahdi.conf */
+	float rxgain;
+	/*! \brief Tx gain set by chan_dahdi.conf */
+	float txgain;
+
+	float txdrc; /*!< Dynamic Range Compression factor. a number between 1 and 6ish */
+	float rxdrc;
+
+	int tonezone;					/*!< tone zone for this chan, or -1 for default */
+	enum DAHDI_IFLIST which_iflist;	/*!< Which interface list is this structure listed? */
+	struct dahdi_pvt *next;				/*!< Next channel in list */
+	struct dahdi_pvt *prev;				/*!< Prev channel in list */
+
+	/* flags */
+
+	/*!
+	 * \brief TRUE if ADSI (Analog Display Services Interface) available
+	 * \note Set from the "adsi" value read in from chan_dahdi.conf
+	 */
+	unsigned int adsi:1;
+	/*!
+	 * \brief TRUE if we can use a polarity reversal to mark when an outgoing
+	 * call is answered by the remote party.
+	 * \note Set from the "answeronpolarityswitch" value read in from chan_dahdi.conf
+	 */
+	unsigned int answeronpolarityswitch:1;
+	/*!
+	 * \brief TRUE if busy detection is enabled.
+	 * (Listens for the beep-beep busy pattern.)
+	 * \note Set from the "busydetect" value read in from chan_dahdi.conf
+	 */
+	unsigned int busydetect:1;
+	/*!
+	 * \brief TRUE if call return is enabled.
+	 * (*69, if your dialplan doesn't catch this first)
+	 * \note Set from the "callreturn" value read in from chan_dahdi.conf
+	 */
+	unsigned int callreturn:1;
+	/*!
+	 * \brief TRUE if busy extensions will hear the call-waiting tone
+	 * and can use hook-flash to switch between callers.
+	 * \note Can be disabled by dialing *70.
+	 * \note Initialized with the "callwaiting" value read in from chan_dahdi.conf
+	 */
+	unsigned int callwaiting:1;
+	/*!
+	 * \brief TRUE if send caller ID for Call Waiting
+	 * \note Set from the "callwaitingcallerid" value read in from chan_dahdi.conf
+	 */
+	unsigned int callwaitingcallerid:1;
+	/*!
+	 * \brief TRUE if support for call forwarding enabled.
+	 * Dial *72 to enable call forwarding.
+	 * Dial *73 to disable call forwarding.
+	 * \note Set from the "cancallforward" value read in from chan_dahdi.conf
+	 */
+	unsigned int cancallforward:1;
+	/*!
+	 * \brief TRUE if support for call parking is enabled.
+	 * \note Set from the "canpark" value read in from chan_dahdi.conf
+	 */
+	unsigned int canpark:1;
+	/*! \brief TRUE if to wait for a DTMF digit to confirm answer */
+	unsigned int confirmanswer:1;
+	/*!
+	 * \brief TRUE if the channel is to be destroyed on hangup.
+	 * (Used by pseudo channels.)
+	 */
+	unsigned int destroy:1;
+	unsigned int didtdd:1;				/*!< flag to say its done it once */
+	/*! \brief TRUE if analog type line dialed no digits in Dial() */
+	unsigned int dialednone:1;
+	/*!
+	 * \brief TRUE if in the process of dialing digits or sending something.
+	 * \note This is used as a receive squelch for ISDN until connected.
+	 */
+	unsigned int dialing:1;
+	/*! \brief TRUE if the transfer capability of the call is digital. */
+	unsigned int digital:1;
+	/*! \brief TRUE if Do-Not-Disturb is enabled, present only for non sig_analog */
+	unsigned int dnd:1;
+	/*! \brief XXX BOOLEAN Purpose??? */
+	unsigned int echobreak:1;
+	/*!
+	 * \brief TRUE if echo cancellation enabled when bridged.
+	 * \note Initialized with the "echocancelwhenbridged" value read in from chan_dahdi.conf
+	 * \note Disabled if the echo canceller is not setup.
+	 */
+	unsigned int echocanbridged:1;
+	/*! \brief TRUE if echo cancellation is turned on. */
+	unsigned int echocanon:1;
+	/*! \brief TRUE if a fax tone has already been handled. */
+	unsigned int faxhandled:1;
+	/*! TRUE if dynamic faxbuffers are configured for use, default is OFF */
+	unsigned int usefaxbuffers:1;
+	/*! TRUE while buffer configuration override is in use */
+	unsigned int bufferoverrideinuse:1;
+	/*! \brief TRUE if over a radio and dahdi_read() has been called. */
+	unsigned int firstradio:1;
+	/*!
+	 * \brief TRUE if the call will be considered "hung up" on a polarity reversal.
+	 * \note Set from the "hanguponpolarityswitch" value read in from chan_dahdi.conf
+	 */
+	unsigned int hanguponpolarityswitch:1;
+	/*! \brief TRUE if DTMF detection needs to be done by hardware. */
+	unsigned int hardwaredtmf:1;
+	/*!
+	 * \brief TRUE if the outgoing caller ID is blocked/hidden.
+	 * \note Caller ID can be disabled by dialing *67.
+	 * \note Caller ID can be enabled by dialing *82.
+	 * \note Initialized with the "hidecallerid" value read in from chan_dahdi.conf
+	 */
+	unsigned int hidecallerid:1;
+	/*!
+	 * \brief TRUE if hide just the name not the number for legacy PBX use.
+	 * \note Only applies to PRI channels.
+	 * \note Set from the "hidecalleridname" value read in from chan_dahdi.conf
+	 */
+	unsigned int hidecalleridname:1;
+	/*! \brief TRUE if DTMF detection is disabled. */
+	unsigned int ignoredtmf:1;
+	/*!
+	 * \brief TRUE if the channel should be answered immediately
+	 * without attempting to gather any digits.
+	 * \note Set from the "immediate" value read in from chan_dahdi.conf
+	 */
+	unsigned int immediate:1;
+	/*! \brief TRUE if in an alarm condition. */
+	unsigned int inalarm:1;
+	/*! \brief TRUE if TDD in MATE mode */
+	unsigned int mate:1;
+	/*! \brief TRUE if we originated the call leg. */
+	unsigned int outgoing:1;
+	/*!
+	 * \brief TRUE if busy extensions will hear the call-waiting tone
+	 * and can use hook-flash to switch between callers.
+	 * \note Set from the "callwaiting" value read in from chan_dahdi.conf
+	 */
+	unsigned int permcallwaiting:1;
+	/*!
+	 * \brief TRUE if the outgoing caller ID is blocked/restricted/hidden.
+	 * \note Set from the "hidecallerid" value read in from chan_dahdi.conf
+	 */
+	unsigned int permhidecallerid:1;
+	/*!
+	 * \brief TRUE if PRI congestion/busy indications are sent out-of-band.
+	 * \note Set from the "priindication" value read in from chan_dahdi.conf
+	 */
+	unsigned int priindication_oob:1;
+	/*!
+	 * \brief TRUE if PRI B channels are always exclusively selected.
+	 * \note Set from the "priexclusive" value read in from chan_dahdi.conf
+	 */
+	unsigned int priexclusive:1;
+	/*!
+	 * \brief TRUE if we will pulse dial.
+	 * \note Set from the "pulsedial" value read in from chan_dahdi.conf
+	 */
+	unsigned int pulse:1;
+	/*! \brief TRUE if a pulsed digit was detected. (Pulse dial phone detected) */
+	unsigned int pulsedial:1;
+	unsigned int restartpending:1;		/*!< flag to ensure counted only once for restart */
+	/*!
+	 * \brief TRUE if caller ID is restricted.
+	 * \note Set but not used.  Should be deleted.  Redundant with permhidecallerid.
+	 * \note Set from the "restrictcid" value read in from chan_dahdi.conf
+	 */
+	unsigned int restrictcid:1;
+	/*!
+	 * \brief TRUE if three way calling is enabled
+	 * \note Set from the "threewaycalling" value read in from chan_dahdi.conf
+	 */
+	unsigned int threewaycalling:1;
+	/*!
+	 * \brief TRUE if call transfer is enabled
+	 * \note For FXS ports (either direct analog or over T1/E1):
+	 *   Support flash-hook call transfer
+	 * \note For digital ports using ISDN PRI protocols:
+	 *   Support switch-side transfer (called 2BCT, RLT or other names)
+	 * \note Set from the "transfer" value read in from chan_dahdi.conf
+	 */
+	unsigned int transfer:1;
+	/*!
+	 * \brief TRUE if caller ID is used on this channel.
+	 * \note PRI and SS7 spans will save caller ID from the networking peer.
+	 * \note FXS ports will generate the caller ID spill.
+	 * \note FXO ports will listen for the caller ID spill.
+	 * \note Set from the "usecallerid" value read in from chan_dahdi.conf
+	 */
+	unsigned int use_callerid:1;
+	/*!
+	 * \brief TRUE if we will use the calling presentation setting
+	 * from the Asterisk channel for outgoing calls.
+	 * \note Only applies to PRI and SS7 channels.
+	 * \note Set from the "usecallingpres" value read in from chan_dahdi.conf
+	 */
+	unsigned int use_callingpres:1;
+	/*!
+	 * \brief TRUE if distinctive rings are to be detected.
+	 * \note For FXO lines
+	 * \note Set indirectly from the "usedistinctiveringdetection" value read in from chan_dahdi.conf
+	 */
+	unsigned int usedistinctiveringdetection:1;
+	/*!
+	 * \brief TRUE if we should use the callerid from incoming call on dahdi transfer.
+	 * \note Set from the "useincomingcalleridondahditransfer" value read in from chan_dahdi.conf
+	 */
+	unsigned int dahditrcallerid:1;
+	/*!
+	 * \brief TRUE if allowed to flash-transfer to busy channels.
+	 * \note Set from the "transfertobusy" value read in from chan_dahdi.conf
+	 */
+	unsigned int transfertobusy:1;
+	/*!
+	 * \brief TRUE if the FXO port monitors for neon type MWI indications from the other end.
+	 * \note Set if the "mwimonitor" value read in contains "neon" from chan_dahdi.conf
+	 */
+	unsigned int mwimonitor_neon:1;
+	/*!
+	 * \brief TRUE if the FXO port monitors for fsk type MWI indications from the other end.
+	 * \note Set if the "mwimonitor" value read in contains "fsk" from chan_dahdi.conf
+	 */
+	unsigned int mwimonitor_fsk:1;
+	/*!
+	 * \brief TRUE if the FXO port monitors for rpas precursor to fsk MWI indications from the other end.
+	 * \note RPAS - Ring Pulse Alert Signal
+	 * \note Set if the "mwimonitor" value read in contains "rpas" from chan_dahdi.conf
+	 */
+	unsigned int mwimonitor_rpas:1;
+	/*! \brief TRUE if an MWI monitor thread is currently active */
+	unsigned int mwimonitoractive:1;
+	/*! \brief TRUE if a MWI message sending thread is active */
+	unsigned int mwisendactive:1;
+	/*!
+	 * \brief TRUE if channel is out of reset and ready
+	 * \note Set but not used.
+	 */
+	unsigned int inservice:1;
+	/*!
+	 * \brief TRUE if the channel is locally blocked.
+	 * \note Applies to SS7 and MFCR2 channels.
+	 */
+	unsigned int locallyblocked:1;
+	/*!
+	 * \brief TRUE if the channel is remotely blocked.
+	 * \note Applies to SS7 and MFCR2 channels.
+	 */
+	unsigned int remotelyblocked:1;
+	/*!
+	 * \brief TRUE if the channel alarms will be managed also as Span ones
+	 * \note Applies to all channels
+	 */
+	unsigned int manages_span_alarms:1;
+
+#if defined(HAVE_PRI)
+	struct sig_pri_span *pri;
+	int logicalspan;
+#endif	/* defined(HAVE_PRI) */
+	/*!
+	 * \brief TRUE if SMDI (Simplified Message Desk Interface) is enabled
+	 * \note Set from the "usesmdi" value read in from chan_dahdi.conf
+	 */
+	unsigned int use_smdi:1;
+	struct mwisend_info mwisend_data;
+	/*! \brief The SMDI interface to get SMDI messages from. */
+	struct ast_smdi_interface *smdi_iface;
+
+	/*! \brief Distinctive Ring data */
+	struct dahdi_distRings drings;
+
+	/*!
+	 * \brief The configured context for incoming calls.
+	 * \note The "context" string read in from chan_dahdi.conf
+	 */
+	char context[AST_MAX_CONTEXT];
+	/*!
+	 * \brief A description for the channel configuration
+	 * \note The "description" string read in from chan_dahdi.conf
+	 */
+	char description[32];
+	/*!
+	 * \brief Saved context string.
+	 */
+	char defcontext[AST_MAX_CONTEXT];
+	/*! \brief Extension to use in the dialplan. */
+	char exten[AST_MAX_EXTENSION];
+	/*!
+	 * \brief Language configured for calls.
+	 * \note The "language" string read in from chan_dahdi.conf
+	 */
+	char language[MAX_LANGUAGE];
+	/*!
+	 * \brief The configured music-on-hold class to use for calls.
+	 * \note The "musicclass" or "mohinterpret" or "musiconhold" string read in from chan_dahdi.conf
+	 */
+	char mohinterpret[MAX_MUSICCLASS];
+	/*!
+	 * \brief Suggested music-on-hold class for peer channel to use for calls.
+	 * \note The "mohsuggest" string read in from chan_dahdi.conf
+	 */
+	char mohsuggest[MAX_MUSICCLASS];
+	char parkinglot[AST_MAX_EXTENSION]; /*!< Parking lot for this channel */
+#if defined(HAVE_PRI) || defined(HAVE_SS7)
+	/*! \brief Automatic Number Identification number (Alternate PRI caller ID number) */
+	char cid_ani[AST_MAX_EXTENSION];
+#endif	/* defined(HAVE_PRI) || defined(HAVE_SS7) */
+	/*! \brief Automatic Number Identification code from PRI */
+	int cid_ani2;
+	/*! \brief Caller ID number from an incoming call. */
+	char cid_num[AST_MAX_EXTENSION];
+	/*!
+	 * \brief Caller ID tag from incoming call
+	 * \note the "cid_tag" string read in from chan_dahdi.conf
+	 */
+	char cid_tag[AST_MAX_EXTENSION];
+	/*! \brief Caller ID Q.931 TON/NPI field values.  Set by PRI. Zero otherwise. */
+	int cid_ton;
+	/*! \brief Caller ID name from an incoming call. */
+	char cid_name[AST_MAX_EXTENSION];
+	/*! \brief Caller ID subaddress from an incoming call. */
+	char cid_subaddr[AST_MAX_EXTENSION];
+	char *origcid_num;				/*!< malloced original callerid */
+	char *origcid_name;				/*!< malloced original callerid */
+	/*! \brief Call waiting number. */
+	char callwait_num[AST_MAX_EXTENSION];
+	/*! \brief Call waiting name. */
+	char callwait_name[AST_MAX_EXTENSION];
+	/*! \brief Redirecting Directory Number Information Service (RDNIS) number */
+	char rdnis[AST_MAX_EXTENSION];
+	/*! \brief Dialed Number Identifier */
+	char dnid[AST_MAX_EXTENSION];
+	/*!
+	 * \brief Bitmapped groups this belongs to.
+	 * \note The "group" bitmapped group string read in from chan_dahdi.conf
+	 */
+	ast_group_t group;
+	/*! \brief Default call PCM encoding format: DAHDI_LAW_ALAW or DAHDI_LAW_MULAW. */
+	int law_default;
+	/*! \brief Active PCM encoding format: DAHDI_LAW_ALAW or DAHDI_LAW_MULAW */
+	int law;
+	int confno;					/*!< Our conference */
+	int confusers;					/*!< Who is using our conference */
+	int propconfno;					/*!< Propagated conference number */
+	/*!
+	 * \brief Bitmapped call groups this belongs to.
+	 * \note The "callgroup" bitmapped group string read in from chan_dahdi.conf
+	 */
+	ast_group_t callgroup;
+	/*!
+	 * \brief Bitmapped pickup groups this belongs to.
+	 * \note The "pickupgroup" bitmapped group string read in from chan_dahdi.conf
+	 */
+	ast_group_t pickupgroup;
+	/*!
+	 * \brief Named call groups this belongs to.
+	 * \note The "namedcallgroup" string read in from chan_dahdi.conf
+	 */
+	struct ast_namedgroups *named_callgroups;
+	/*!
+	 * \brief Named pickup groups this belongs to.
+	 * \note The "namedpickupgroup" string read in from chan_dahdi.conf
+	 */
+	struct ast_namedgroups *named_pickupgroups;
+	/*!
+	 * \brief Channel variable list with associated values to set when a channel is created.
+	 * \note The "setvar" strings read in from chan_dahdi.conf
+	 */
+	struct ast_variable *vars;
+	int channel;					/*!< Channel Number */
+	int span;					/*!< Span number */
+	time_t guardtime;				/*!< Must wait this much time before using for new call */
+	int cid_signalling;				/*!< CID signalling type bell202 or v23 */
+	int cid_start;					/*!< CID start indicator, polarity or ring or DTMF without warning event */
+	int dtmfcid_holdoff_state;		/*!< State indicator that allows for line to settle before checking for dtmf energy */
+	struct timeval	dtmfcid_delay;  /*!< Time value used for allow line to settle */
+	int callingpres;				/*!< The value of calling presentation that we're going to use when placing a PRI call */
+	int callwaitingrepeat;				/*!< How many samples to wait before repeating call waiting */
+	int cidcwexpire;				/*!< When to stop waiting for CID/CW CAS response (In samples) */
+	int cid_suppress_expire;		/*!< How many samples to suppress after a CID spill. */
+	/*! \brief Analog caller ID waveform sample buffer */
+	unsigned char *cidspill;
+	/*! \brief Position in the cidspill buffer to send out next. */
+	int cidpos;
+	/*! \brief Length of the cidspill buffer containing samples. */
+	int cidlen;
+	/*! \brief Ring timeout timer?? */
+	int ringt;
+	/*!
+	 * \brief Ring timeout base.
+	 * \note Value computed indirectly from "ringtimeout" read in from chan_dahdi.conf
+	 */
+	int ringt_base;
+	/*!
+	 * \brief Number of most significant digits/characters to strip from the dialed number.
+	 * \note Feature is deprecated.  Use dialplan logic.
+	 * \note The characters are stripped before the PRI TON/NPI prefix
+	 * characters are processed.
+	 */
+	int stripmsd;
+	/*!
+	 * \brief TRUE if Call Waiting (CW) CPE Alert Signal (CAS) is being sent.
+	 * \note
+	 * After CAS is sent, the call waiting caller id will be sent if the phone
+	 * gives a positive reply.
+	 */
+	int callwaitcas;
+	/*! \brief Number of call waiting rings. */
+	int callwaitrings;
+	/*! \brief Echo cancel parameters. */
+	struct {
+		struct dahdi_echocanparams head;
+		struct dahdi_echocanparam params[DAHDI_MAX_ECHOCANPARAMS];
+	} echocancel;
+	/*!
+	 * \brief Echo training time. 0 = disabled
+	 * \note Set from the "echotraining" value read in from chan_dahdi.conf
+	 */
+	int echotraining;
+	/*! \brief Filled with 'w'.  XXX Purpose?? */
+	char echorest[20];
+	/*!
+	 * \brief Number of times to see "busy" tone before hanging up.
+	 * \note Set from the "busycount" value read in from chan_dahdi.conf
+	 */
+	int busycount;
+	/*!
+	 * \brief Busy cadence pattern description.
+	 * \note Set from the "busypattern" value read from chan_dahdi.conf
+	 */
+	struct ast_dsp_busy_pattern busy_cadence;
+	/*!
+	 * \brief Bitmapped call progress detection flags. CALLPROGRESS_xxx values.
+	 * \note Bits set from the "callprogress" and "faxdetect" values read in from chan_dahdi.conf
+	 */
+	int callprogress;
+	/*!
+	 * \brief Number of milliseconds to wait for dialtone.
+	 * \note Set from the "waitfordialtone" value read in from chan_dahdi.conf
+	 */
+	int waitfordialtone;
+	/*!
+	 * \brief Number of frames to watch for dialtone in incoming calls
+	 * \note Set from the "dialtone_detect" value read in from chan_dahdi.conf
+	 */
+	int dialtone_detect;
+	int dialtone_scanning_time_elapsed;	/*!< Amount of audio scanned for dialtone, in frames */
+	struct timeval waitingfordt;			/*!< Time we started waiting for dialtone */
+	struct timeval flashtime;			/*!< Last flash-hook time */
+	/*! \brief Opaque DSP configuration structure. */
+	struct ast_dsp *dsp;
+	/*! \brief DAHDI dial operation command struct for ioctl() call. */
+	struct dahdi_dialoperation dop;
+	int whichwink;					/*!< SIG_FEATDMF_TA Which wink are we on? */
+	/*! \brief Second part of SIG_FEATDMF_TA wink operation. */
+	char finaldial[64];
+	char accountcode[AST_MAX_ACCOUNT_CODE];		/*!< Account code */
+	int amaflags;					/*!< AMA Flags */
+	struct tdd_state *tdd;				/*!< TDD flag */
+	/*! \brief Accumulated call forwarding number. */
+	char call_forward[AST_MAX_EXTENSION];
+	/*!
+	 * \brief Voice mailbox location.
+	 * \note Set from the "mailbox" string read in from chan_dahdi.conf
+	 */
+	char mailbox[AST_MAX_EXTENSION];
+	/*! \brief Opaque event subscription parameters for message waiting indication support. */
+	struct stasis_subscription *mwi_event_sub;
+	/*! \brief Delayed dialing for E911.  Overlap digits for ISDN. */
+	char dialdest[256];
+#ifdef HAVE_DAHDI_LINEREVERSE_VMWI
+	struct dahdi_vmwi_info mwisend_setting;				/*!< Which VMWI methods to use */
+	unsigned int mwisend_fsk: 1;		/*! Variable for enabling FSK MWI handling in chan_dahdi */
+	unsigned int mwisend_rpas:1;		/*! Variable for enabling Ring Pulse Alert before MWI FSK Spill */
+#endif
+	int distinctivering;				/*!< Which distinctivering to use */
+	int dtmfrelax;					/*!< whether to run in relaxed DTMF mode */
+	/*! \brief Holding place for event injected from outside normal operation. */
+	int fake_event;
+	/*!
+	 * \brief Minimal time period (ms) between the answer polarity
+	 * switch and hangup polarity switch.
+	 */
+	int polarityonanswerdelay;
+	/*! \brief Start delay time if polarityonanswerdelay is nonzero. */
+	struct timeval polaritydelaytv;
+	/*!
+	 * \brief Send caller ID on FXS after this many rings. Set to 1 for US.
+	 * \note Set from the "sendcalleridafter" value read in from chan_dahdi.conf
+	 */
+	int sendcalleridafter;
+	/*! \brief Current line interface polarity. POLARITY_IDLE, POLARITY_REV */
+	int polarity;
+	/*! \brief DSP feature flags: DSP_FEATURE_xxx */
+	int dsp_features;
+#if defined(HAVE_SS7)
+	/*! \brief SS7 control parameters */
+	struct sig_ss7_linkset *ss7;
+#endif	/* defined(HAVE_SS7) */
+#if defined(HAVE_OPENR2)
+	struct dahdi_mfcr2 *mfcr2;
+	openr2_chan_t *r2chan;
+	openr2_calling_party_category_t mfcr2_recvd_category;
+	openr2_calling_party_category_t mfcr2_category;
+	int mfcr2_dnis_index;
+	int mfcr2_ani_index;
+	int mfcr2call:1;
+	int mfcr2_answer_pending:1;
+	int mfcr2_charge_calls:1;
+	int mfcr2_allow_collect_calls:1;
+	int mfcr2_forced_release:1;
+	int mfcr2_dnis_matched:1;
+	int mfcr2_call_accepted:1;
+	int mfcr2_accept_on_offer:1;
+	int mfcr2_progress_sent:1;
+#endif	/* defined(HAVE_OPENR2) */
+	/*! \brief DTMF digit in progress.  0 when no digit in progress. */
+	char begindigit;
+	/*! \brief TRUE if confrence is muted. */
+	int muting;
+	void *sig_pvt;
+	struct ast_cc_config_params *cc_params;
+	/* DAHDI channel names may differ greatly from the
+	 * string that was provided to an app such as Dial. We
+	 * need to save the original string passed to dahdi_request
+	 * for call completion purposes. This way, we can replicate
+	 * the original dialed string later.
+	 */
+	char dialstring[AST_CHANNEL_NAME];
+};
+
+
+/* Analog signaling */
+#define SIG_EM          DAHDI_SIG_EM
+#define SIG_EMWINK      (0x0100000 | DAHDI_SIG_EM)
+#define SIG_FEATD       (0x0200000 | DAHDI_SIG_EM)
+#define SIG_FEATDMF     (0x0400000 | DAHDI_SIG_EM)
+#define SIG_FEATB       (0x0800000 | DAHDI_SIG_EM)
+#define SIG_E911        (0x1000000 | DAHDI_SIG_EM)
+#define SIG_FEATDMF_TA  (0x2000000 | DAHDI_SIG_EM)
+#define SIG_FGC_CAMA    (0x4000000 | DAHDI_SIG_EM)
+#define SIG_FGC_CAMAMF  (0x8000000 | DAHDI_SIG_EM)
+#define SIG_FXSLS       DAHDI_SIG_FXSLS
+#define SIG_FXSGS       DAHDI_SIG_FXSGS
+#define SIG_FXSKS       DAHDI_SIG_FXSKS
+#define SIG_FXOLS       DAHDI_SIG_FXOLS
+#define SIG_FXOGS       DAHDI_SIG_FXOGS
+#define SIG_FXOKS       DAHDI_SIG_FXOKS
+#define SIG_SF          DAHDI_SIG_SF
+#define SIG_SFWINK      (0x0100000 | DAHDI_SIG_SF)
+#define SIG_SF_FEATD    (0x0200000 | DAHDI_SIG_SF)
+#define SIG_SF_FEATDMF  (0x0400000 | DAHDI_SIG_SF)
+#define SIG_SF_FEATB    (0x0800000 | DAHDI_SIG_SF)
+#define SIG_EM_E1       DAHDI_SIG_EM_E1
+
+/* PRI signaling */
+#define SIG_PRI         DAHDI_SIG_CLEAR
+#define SIG_BRI         (0x2000000 | DAHDI_SIG_CLEAR)
+#define SIG_BRI_PTMP    (0X4000000 | DAHDI_SIG_CLEAR)
+
+/* SS7 signaling */
+#define SIG_SS7         (0x1000000 | DAHDI_SIG_CLEAR)
+
+/* MFC/R2 signaling */
+#define SIG_MFCR2       DAHDI_SIG_CAS
+
+
+#define SIG_PRI_LIB_HANDLE_CASES	\
+	SIG_PRI:						\
+	case SIG_BRI:					\
+	case SIG_BRI_PTMP
+
+/*!
+ * \internal
+ * \brief Determine if sig_pri handles the signaling.
+ * \since 1.8
+ *
+ * \param signaling Signaling to determine if is for sig_pri.
+ *
+ * \return TRUE if the signaling is for sig_pri.
+ */
+static inline int dahdi_sig_pri_lib_handles(int signaling)
+{
+	int handles;
+
+	switch (signaling) {
+	case SIG_PRI_LIB_HANDLE_CASES:
+		handles = 1;
+		break;
+	default:
+		handles = 0;
+		break;
+	}
+
+	return handles;
+}
+
+static inline int analog_lib_handles(int signalling, int radio, int oprmode)
+{
+	switch (signalling) {
+	case SIG_FXOLS:
+	case SIG_FXOGS:
+	case SIG_FXOKS:
+	case SIG_FXSLS:
+	case SIG_FXSGS:
+	case SIG_FXSKS:
+	case SIG_EMWINK:
+	case SIG_EM:
+	case SIG_EM_E1:
+	case SIG_FEATD:
+	case SIG_FEATDMF:
+	case SIG_E911:
+	case SIG_FGC_CAMA:
+	case SIG_FGC_CAMAMF:
+	case SIG_FEATB:
+	case SIG_SFWINK:
+	case SIG_SF:
+	case SIG_SF_FEATD:
+	case SIG_SF_FEATDMF:
+	case SIG_FEATDMF_TA:
+	case SIG_SF_FEATB:
+		break;
+	default:
+		/* The rest of the function should cover the remainder of signalling types */
+		return 0;
+	}
+
+	if (radio) {
+		return 0;
+	}
+
+	if (oprmode) {
+		return 0;
+	}
+
+	return 1;
+}
+
+#define dahdi_get_index(ast, p, nullok)	_dahdi_get_index(ast, p, nullok, __PRETTY_FUNCTION__, __LINE__)
+int _dahdi_get_index(struct ast_channel *ast, struct dahdi_pvt *p, int nullok, const char *fname, unsigned long line);
+
+void disable_dtmf_detect(struct dahdi_pvt *p);
+void enable_dtmf_detect(struct dahdi_pvt *p);
+
+void dahdi_enable_ec(struct dahdi_pvt *p);
+void dahdi_disable_ec(struct dahdi_pvt *p);
+
+void update_conf(struct dahdi_pvt *p);
+void dahdi_link(struct dahdi_pvt *slave, struct dahdi_pvt *master);
+void dahdi_unlink(struct dahdi_pvt *slave, struct dahdi_pvt *master, int needlock);
+
+/* ------------------------------------------------------------------- */
+
+#if defined(__cplusplus) || defined(c_plusplus)
+}
+#endif
+
+#endif	/* _ASTERISK_CHAN_DAHDI_H */
diff --git a/channels/dahdi/bridge_native_dahdi.c b/channels/dahdi/bridge_native_dahdi.c
new file mode 100644
index 000000000..611994f5e
--- /dev/null
+++ b/channels/dahdi/bridge_native_dahdi.c
@@ -0,0 +1,928 @@
+/*
+ * Asterisk -- An open source telephony toolkit.
+ *
+ * Copyright (C) 2013 Digium, Inc.
+ *
+ * Richard Mudgett <rmudgett@digium.com>
+ *
+ * See http://www.asterisk.org for more information about
+ * the Asterisk project. Please do not directly contact
+ * any of the maintainers of this project for assistance;
+ * the project provides a web site, mailing lists and IRC
+ * channels for your use.
+ *
+ * This program is free software, distributed under the terms of
+ * the GNU General Public License Version 2. See the LICENSE file
+ * at the top of the source tree.
+ */
+
+/*!
+ * \file
+ * \brief Native DAHDI bridging support.
+ *
+ * \author Richard Mudgett <rmudgett@digium.com>
+ *
+ * See Also:
+ * \arg \ref AstCREDITS
+ */
+
+/*** MODULEINFO
+	<support_level>core</support_level>
+ ***/
+
+#include "asterisk.h"
+
+ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
+
+#include "../sig_analog.h"
+#if defined(HAVE_PRI)
+#include "../sig_pri.h"
+#endif	/* defined(HAVE_PRI) */
+#include "../chan_dahdi.h"
+
+#include "asterisk/astobj.h"
+#include "bridge_native_dahdi.h"
+#include "asterisk/bridging.h"
+#include "asterisk/bridging_technology.h"
+#include "asterisk/frame.h"
+
+/* ------------------------------------------------------------------- */
+
+static const struct ast_channel_tech *dahdi_tech;
+
+struct native_pvt_chan {
+	/*! Original private. */
+	struct dahdi_pvt *pvt;
+	/*! Original private owner. */
+	struct ast_channel *owner;
+	/*! Original owner index. */
+	int index;
+	/*! Original file descriptor 0. */
+	int fd0;
+	/*! Original channel state. */
+	int state;
+	/*! Original inthreeway. */
+	unsigned int inthreeway:1;
+};
+
+struct native_pvt_bridge {
+	/*! Master channel in the native bridge. */
+	struct dahdi_pvt *master;
+	/*! Slave channel in the native bridge. */
+	struct dahdi_pvt *slave;
+	/*! TRUE if the bridge can start when ready. */
+	unsigned int saw_start:1;
+	/*! TRUE if the channels are connected in a conference. */
+	unsigned int connected:1;
+#if defined(HAVE_PRI) && defined(PRI_2BCT)
+	/*!
+	 * \brief TRUE if tried to eliminate possible PRI tromboned call.
+	 *
+	 * \note A tromboned call uses two B channels of the same ISDN
+	 * span.  One leg comes into Asterisk, the other leg goes out of
+	 * Asterisk, and Asterisk is natively bridging the two legs.
+	 */
+	unsigned int tried_trombone_removal:1;
+#endif	/* defined(HAVE_PRI) && defined(PRI_2BCT) */
+};
+
+/*!
+ * \internal
+ * \brief Create a bridge technology instance for a bridge.
+ * \since 12.0.0
+ *
+ * \retval 0 on success
+ * \retval -1 on failure
+ *
+ * \note On entry, bridge may or may not already be locked.
+ * However, it can be accessed as if it were locked.
+ */
+static int native_bridge_create(struct ast_bridge *bridge)
+{
+	struct native_pvt_bridge *tech_pvt;
+
+	ast_assert(!bridge->tech_pvt);
+
+	tech_pvt = ast_calloc(1, sizeof(*tech_pvt));
+	if (!tech_pvt) {
+		return -1;
+	}
+
+	bridge->tech_pvt = tech_pvt;
+	return 0;
+}
+
+/*!
+ * \internal
+ * \brief Destroy a bridging technology instance for a bridge.
+ * \since 12.0.0
+ *
+ * \note On entry, bridge must NOT be locked.
+ */
+static void native_bridge_destroy(struct ast_bridge *bridge)
+{
+	struct native_pvt_bridge *tech_pvt;
+
+	tech_pvt = bridge->tech_pvt;
+	bridge->tech_pvt = NULL;
+	ast_free(tech_pvt);
+}
+
+/*!
+ * \internal
+ * \brief Stop native bridging activity.
+ * \since 12.0.0
+ *
+ * \param bridge What to operate upon.
+ *
+ * \return Nothing
+ *
+ * \note On entry, bridge is already locked.
+ */
+static void native_stop(struct ast_bridge *bridge)
+{
+	struct native_pvt_bridge *bridge_tech_pvt;
+	struct ast_bridge_channel *cur;
+
+	ast_assert(bridge->tech_pvt != NULL);
+
+	AST_LIST_TRAVERSE(&bridge->channels, cur, entry) {
+		struct native_pvt_chan *chan_tech_pvt;
+
+		chan_tech_pvt = cur->tech_pvt;
+		if (!chan_tech_pvt) {
+			continue;
+		}
+
+		ast_mutex_lock(&chan_tech_pvt->pvt->lock);
+		if (chan_tech_pvt->pvt == ast_channel_tech_pvt(cur->chan)) {
+			dahdi_enable_ec(chan_tech_pvt->pvt);
+		}
+		if (chan_tech_pvt->index == SUB_REAL) {
+			enable_dtmf_detect(chan_tech_pvt->pvt);
+		}
+		ast_mutex_unlock(&chan_tech_pvt->pvt->lock);
+	}
+
+	bridge_tech_pvt = bridge->tech_pvt;
+	dahdi_unlink(bridge_tech_pvt->slave, bridge_tech_pvt->master, 1);
+
+	ast_debug(2, "Stop native bridging %s and %s\n",
+		ast_channel_name(AST_LIST_FIRST(&bridge->channels)->chan),
+		ast_channel_name(AST_LIST_LAST(&bridge->channels)->chan));
+}
+
+/*!
+ * \internal
+ * \brief Request to stop native bridging activity.
+ * \since 12.0.0
+ *
+ * \param bridge What to operate upon.
+ *
+ * \return Nothing
+ *
+ * \note On entry, bridge is already locked.
+ */
+static void native_request_stop(struct ast_bridge *bridge)
+{
+	struct native_pvt_bridge *tech_pvt;
+
+	ast_assert(bridge->tech_pvt != NULL);
+
+	tech_pvt = bridge->tech_pvt;
+	if (!tech_pvt->connected) {
+		return;
+	}
+	tech_pvt->connected = 0;
+
+	/* Now to actually stop the bridge. */
+	native_stop(bridge);
+}
+
+/*!
+ * \internal
+ * \brief Start native bridging activity.
+ * \since 12.0.0
+ *
+ * \param bridge What to operate upon.
+ *
+ * \retval 0 on success.
+ * \retval -1 on error.  Could not start the bridge.
+ *
+ * \note On entry, bridge may or may not already be locked.
+ * However, it can be accessed as if it were locked.
+ */
+static int native_start(struct ast_bridge *bridge)
+{
+	struct native_pvt_bridge *tech_pvt;
+	struct ast_bridge_channel *bc0;
+	struct ast_bridge_channel *bc1;
+	struct native_pvt_chan *npc0;
+	struct native_pvt_chan *npc1;
+	struct ast_channel *c0;
+	struct ast_channel *c1;
+	struct dahdi_pvt *p0;
+	struct dahdi_pvt *p1;
+	struct dahdi_pvt *master;
+	struct dahdi_pvt *slave;
+	int inconf;
+	int nothing_ok;
+
+	ast_assert(bridge->tech_pvt != NULL);
+
+	bc0 = AST_LIST_FIRST(&bridge->channels);
+	bc1 = AST_LIST_LAST(&bridge->channels);
+	c0 = bc0->chan;
+	c1 = bc1->chan;
+
+	/* Lock channels and privates */
+	for (;;) {
+		ast_channel_lock(c0);
+		if (!ast_channel_trylock(c1)) {
+			p0 = ast_channel_tech_pvt(c0);
+			if (!ast_mutex_trylock(&p0->lock)) {
+				p1 = ast_channel_tech_pvt(c1);
+				if (!ast_mutex_trylock(&p1->lock)) {
+					/* Got all locks */
+					break;
+				}
+				ast_mutex_unlock(&p0->lock);
+			}
+			ast_channel_unlock(c1);
+		}
+		ast_channel_unlock(c0);
+		sched_yield();
+	}
+
+	npc0 = bc0->tech_pvt;
+	ast_assert(npc0 != NULL);
+	npc0->pvt = p0;
+	npc0->owner = p0->owner;
+	npc0->index = dahdi_get_index(c0, p0, 0);
+	npc0->fd0 = ast_channel_fd(c0, 0);
+	npc0->state = -1;
+	npc0->inthreeway = p0->subs[SUB_REAL].inthreeway;
+
+	npc1 = bc1->tech_pvt;
+	ast_assert(npc1 != NULL);
+	npc1->pvt = p1;
+	npc1->owner = p1->owner;
+	npc1->index = dahdi_get_index(c1, p1, 0);
+	npc1->fd0 = ast_channel_fd(c1, 0);
+	npc1->state = -1;
+	npc1->inthreeway = p1->subs[SUB_REAL].inthreeway;
+
+	/*
+	 * Check things that can change on the privates while in native
+	 * bridging and cause native to not activate.
+	 */
+	if (npc0->index < 0 || npc1->index < 0
+#if defined(HAVE_PRI)
+		/*
+		 * PRI nobch channels (hold and call waiting) are equivalent to
+		 * pseudo channels and cannot be nativly bridged.
+		 */
+		|| (dahdi_sig_pri_lib_handles(p0->sig)
+			&& ((struct sig_pri_chan *) p0->sig_pvt)->no_b_channel)
+		|| (dahdi_sig_pri_lib_handles(p1->sig)
+			&& ((struct sig_pri_chan *) p1->sig_pvt)->no_b_channel)
+#endif	/* defined(HAVE_PRI) */
+		) {
+		ast_mutex_unlock(&p0->lock);
+		ast_mutex_unlock(&p1->lock);
+		ast_channel_unlock(c0);
+		ast_channel_unlock(c1);
+		return -1;
+	}
+
+	inconf = 0;
+	nothing_ok = 1;
+	master = NULL;
+	slave = NULL;
+	if (npc0->index == SUB_REAL && npc1->index == SUB_REAL) {
+		if (p0->owner && p1->owner) {
+			/*
+			 * If we don't have a call-wait in a 3-way, and we aren't in a
+			 * 3-way, we can be master.
+			 */
+			if (!p0->subs[SUB_CALLWAIT].inthreeway && !p1->subs[SUB_REAL].inthreeway) {
+				master = p0;
+				slave = p1;
+				inconf = 1;
+			} else if (!p1->subs[SUB_CALLWAIT].inthreeway && !p0->subs[SUB_REAL].inthreeway) {
+				master = p1;
+				slave = p0;
+				inconf = 1;
+			} else {
+				ast_log(LOG_WARNING, "Huh?  Both calls are callwaits or 3-ways?  That's clever...?\n");
+				ast_log(LOG_WARNING, "p0: chan %d/%d/CW%d/3W%d, p1: chan %d/%d/CW%d/3W%d\n",
+					p0->channel,
+					npc0->index, (p0->subs[SUB_CALLWAIT].dfd > -1) ? 1 : 0,
+					p0->subs[SUB_REAL].inthreeway,
+					p0->channel,
+					npc0->index, (p1->subs[SUB_CALLWAIT].dfd > -1) ? 1 : 0,
+					p1->subs[SUB_REAL].inthreeway);
+			}
+			nothing_ok = 0;
+		}
+	} else if (npc0->index == SUB_REAL && npc1->index == SUB_THREEWAY) {
+		if (p1->subs[SUB_THREEWAY].inthreeway) {
+			master = p1;
+			slave = p0;
+			nothing_ok = 0;
+		}
+	} else if (npc0->index == SUB_THREEWAY && npc1->index == SUB_REAL) {
+		if (p0->subs[SUB_THREEWAY].inthreeway) {
+			master = p0;
+			slave = p1;
+			nothing_ok = 0;
+		}
+	} else if (npc0->index == SUB_REAL && npc1->index == SUB_CALLWAIT) {
+		/*
+		 * We have a real and a call wait.  If we're in a three way
+		 * call, put us in it, otherwise, don't put us in anything.
+		 */
+		if (p1->subs[SUB_CALLWAIT].inthreeway) {
+			master = p1;
+			slave = p0;
+			nothing_ok = 0;
+		}
+	} else if (npc0->index == SUB_CALLWAIT && npc1->index == SUB_REAL) {
+		/* Same as previous */
+		if (p0->subs[SUB_CALLWAIT].inthreeway) {
+			master = p0;
+			slave = p1;
+			nothing_ok = 0;
+		}
+	}
+	ast_debug(3, "master: %d, slave: %d, nothing_ok: %d\n",
+		master ? master->channel : 0,
+		slave ? slave->channel : 0,
+		nothing_ok);
+	if (master && slave) {
+		/*
+		 * Stop any tones, or play ringtone as appropriate.  If they are
+		 * bridged in an active threeway call with a channel that is
+		 * ringing, we should indicate ringing.
+		 */
+		if (npc1->index == SUB_THREEWAY
+			&& p1->subs[SUB_THREEWAY].inthreeway
+			&& p1->subs[SUB_REAL].owner
+			&& p1->subs[SUB_REAL].inthreeway
+			&& ast_channel_state(p1->subs[SUB_REAL].owner) == AST_STATE_RINGING) {
+			ast_debug(2,
+				"Playing ringback on %d/%d(%s) since %d/%d(%s) is in a ringing three-way\n",
+				p0->channel, npc0->index, ast_channel_name(c0),
+				p1->channel, npc1->index, ast_channel_name(c1));
+			tone_zone_play_tone(p0->subs[npc0->index].dfd, DAHDI_TONE_RINGTONE);
+			npc1->state = ast_channel_state(p1->subs[SUB_REAL].owner);
+		} else {
+			ast_debug(2, "Stopping tones on %d/%d(%s) talking to %d/%d(%s)\n",
+				p0->channel, npc0->index, ast_channel_name(c0),
+				p1->channel, npc1->index, ast_channel_name(c1));
+			tone_zone_play_tone(p0->subs[npc0->index].dfd, -1);
+		}
+
+		if (npc0->index == SUB_THREEWAY
+			&& p0->subs[SUB_THREEWAY].inthreeway
+			&& p0->subs[SUB_REAL].owner
+			&& p0->subs[SUB_REAL].inthreeway
+			&& ast_channel_state(p0->subs[SUB_REAL].owner) == AST_STATE_RINGING) {
+			ast_debug(2,
+				"Playing ringback on %d/%d(%s) since %d/%d(%s) is in a ringing three-way\n",
+				p1->channel, npc1->index, ast_channel_name(c1),
+				p0->channel, npc0->index, ast_channel_name(c0));
+			tone_zone_play_tone(p1->subs[npc1->index].dfd, DAHDI_TONE_RINGTONE);
+			npc0->state = ast_channel_state(p0->subs[SUB_REAL].owner);
+		} else {
+			ast_debug(2, "Stopping tones on %d/%d(%s) talking to %d/%d(%s)\n",
+				p1->channel, npc1->index, ast_channel_name(c1),
+				p0->channel, npc0->index, ast_channel_name(c0));
+			tone_zone_play_tone(p1->subs[npc1->index].dfd, -1);
+		}
+
+		if (npc0->index == SUB_REAL && npc1->index == SUB_REAL) {
+			if (!p0->echocanbridged || !p1->echocanbridged) {
+				/* Disable echo cancellation if appropriate */
+				dahdi_disable_ec(p0);
+				dahdi_disable_ec(p1);
+			}
+		}
+		dahdi_link(slave, master);
+		master->inconference = inconf;
+	} else if (!nothing_ok) {
+		ast_log(LOG_WARNING, "Can't link %d/%s with %d/%s\n",
+			p0->channel, subnames[npc0->index],
+			p1->channel, subnames[npc1->index]);
+	}
+	update_conf(p0);
+	update_conf(p1);
+
+	ast_channel_unlock(c0);
+	ast_channel_unlock(c1);
+
+	/* Native bridge failed */
+	if ((!master || !slave) && !nothing_ok) {
+		ast_mutex_unlock(&p0->lock);
+		ast_mutex_unlock(&p1->lock);
+		return -1;
+	}
+
+	if (npc0->index == SUB_REAL) {
+		disable_dtmf_detect(p0);
+	}
+	if (npc1->index == SUB_REAL) {
+		disable_dtmf_detect(p1);
+	}
+
+	ast_mutex_unlock(&p0->lock);
+	ast_mutex_unlock(&p1->lock);
+
+	tech_pvt = bridge->tech_pvt;
+	tech_pvt->master = master;
+	tech_pvt->slave = slave;
+
+	ast_debug(2, "Start native bridging %s and %s\n",
+		ast_channel_name(c0), ast_channel_name(c1));
+
+#if defined(HAVE_PRI) && defined(PRI_2BCT)
+	if (!tech_pvt->tried_trombone_removal) {
+		tech_pvt->tried_trombone_removal = 1;
+
+		if (p0->pri && p0->pri == p1->pri && p0->pri->transfer) {
+			q931_call *q931_c0;
+			q931_call *q931_c1;
+
+			/* Try to eliminate the tromboned call. */
+			ast_mutex_lock(&p0->pri->lock);
+			ast_assert(dahdi_sig_pri_lib_handles(p0->sig));
+			ast_assert(dahdi_sig_pri_lib_handles(p1->sig));
+			q931_c0 = ((struct sig_pri_chan *) (p0->sig_pvt))->call;
+			q931_c1 = ((struct sig_pri_chan *) (p1->sig_pvt))->call;
+			if (q931_c0 && q931_c1) {
+				pri_channel_bridge(q931_c0, q931_c1);
+				ast_debug(2, "Attempt to eliminate tromboned call with %s and %s\n",
+					ast_channel_name(c0), ast_channel_name(c1));
+			}
+			ast_mutex_unlock(&p0->pri->lock);
+		}
+	}
+#endif	/* defined(HAVE_PRI) && defined(PRI_2BCT) */
+	return 0;
+}
+
+/*!
+ * \internal
+ * \brief Request to start native bridging activity.
+ * \since 12.0.0
+ *
+ * \param bridge What to operate upon.
+ *
+ * \return Nothing
+ *
+ * \note On entry, bridge may or may not already be locked.
+ * However, it can be accessed as if it were locked.
+ */
+static void native_request_start(struct ast_bridge *bridge)
+{
+	struct native_pvt_bridge *tech_pvt;
+	struct ast_bridge_channel *cur;
+
+	ast_assert(bridge->tech_pvt != NULL);
+
+	tech_pvt = bridge->tech_pvt;
+
+	if (bridge->num_channels != 2 || !tech_pvt->saw_start || tech_pvt->connected) {
+		return;
+	}
+	AST_LIST_TRAVERSE(&bridge->channels, cur, entry) {
+		if (cur->suspended || !cur->tech_pvt) {
+			return;
+		}
+	}
+
+	/* Actually try starting the native bridge. */
+	if (native_start(bridge)) {
+		return;
+	}
+	tech_pvt->connected = 1;
+}
+
+/*!
+ * \internal
+ * \brief Request a bridge technology instance start operations.
+ * \since 12.0.0
+ *
+ * \retval 0 on success
+ * \retval -1 on failure
+ *
+ * \note On entry, bridge may or may not already be locked.
+ * However, it can be accessed as if it were locked.
+ */
+static int native_bridge_start(struct ast_bridge *bridge)
+{
+	struct native_pvt_bridge *tech_pvt;
+
+	ast_assert(bridge->tech_pvt != NULL);
+
+	tech_pvt = bridge->tech_pvt;
+	tech_pvt->saw_start = 1;
+
+	native_request_start(bridge);
+	return 0;
+}
+
+/*!
+ * \internal
+ * \brief Request a bridge technology instance stop in preparation for being destroyed.
+ * \since 12.0.0
+ *
+ * \note On entry, bridge is already locked.
+ */
+static void native_bridge_stop(struct ast_bridge *bridge)
+{
+	struct native_pvt_bridge *tech_pvt;
+
+	tech_pvt = bridge->tech_pvt;
+	if (!tech_pvt) {
+		return;
+	}
+
+	tech_pvt->saw_start = 0;
+	native_request_stop(bridge);
+}
+
+/*!
+ * \internal
+ * \brief Add a channel to a bridging technology instance for a bridge.
+ * \since 12.0.0
+ *
+ * \retval 0 on success
+ * \retval -1 on failure
+ *
+ * \note On entry, bridge is already locked.
+ */
+static int native_bridge_join(struct ast_bridge *bridge, struct ast_bridge_channel *bridge_channel)
+{
+	struct native_pvt_chan *tech_pvt;
+	struct ast_channel *c0;
+	struct ast_channel *c1;
+
+	ast_assert(!bridge_channel->tech_pvt);
+
+	tech_pvt = ast_calloc(1, sizeof(*tech_pvt));
+	if (!tech_pvt) {
+		return -1;
+	}
+
+	bridge_channel->tech_pvt = tech_pvt;
+	native_request_start(bridge);
+
+	c0 = AST_LIST_FIRST(&bridge->channels)->chan;
+	c1 = AST_LIST_LAST(&bridge->channels)->chan;
+	if (c0 != c1) {
+		/*
+		 * Make the channels compatible in case the native bridge did
+		 * not start for some reason and we need to fallback to 1-1
+		 * bridging.
+		 */
+		ast_channel_make_compatible(c0, c1);
+	}
+
+	return 0;
+}
+
+/*!
+ * \internal
+ * \brief Remove a channel from a bridging technology instance for a bridge.
+ * \since 12.0.0
+ *
+ * \note On entry, bridge is already locked.
+ */
+static void native_bridge_leave(struct ast_bridge *bridge, struct ast_bridge_channel *bridge_channel)
+{
+	struct native_pvt_chan *tech_pvt;
+
+	native_request_stop(bridge);
+
+	tech_pvt = bridge_channel->tech_pvt;
+	bridge_channel->tech_pvt = NULL;
+	ast_free(tech_pvt);
+}
+
+/*!
+ * \internal
+ * \brief Suspend a channel on a bridging technology instance for a bridge.
+ * \since 12.0.0
+ *
+ * \note On entry, bridge is already locked.
+ */
+static void native_bridge_suspend(struct ast_bridge *bridge, struct ast_bridge_channel *bridge_channel)
+{
+	native_request_stop(bridge);
+}
+
+/*!
+ * \internal
+ * \brief Unsuspend a channel on a bridging technology instance for a bridge.
+ * \since 12.0.0
+ *
+ * \note On entry, bridge is already locked.
+ */
+static void native_bridge_unsuspend(struct ast_bridge *bridge, struct ast_bridge_channel *bridge_channel)
+{
+	native_request_start(bridge);
+}
+
+/*!
+ * \internal
+ * \brief Check if channel is compatible.
+ * \since 12.0.0
+ *
+ * \param bridge_channel Is this channel compatible.
+ *
+ * \retval TRUE if channel is compatible with native DAHDI bridge.
+ */
+static int native_bridge_is_capable(struct ast_bridge_channel *bridge_channel)
+{
+	struct ast_channel *chan = bridge_channel->chan;
+	struct dahdi_pvt *pvt;
+	int is_capable;
+
+	if (ao2_container_count(bridge_channel->features->dtmf_hooks)) {
+		ast_debug(2, "Channel '%s' has DTMF hooks.\n", ast_channel_name(chan));
+		return 0;
+	}
+
+	ast_channel_lock(chan);
+
+	if (dahdi_tech != ast_channel_tech(chan)) {
+		ast_debug(2, "Channel '%s' is not %s.\n",
+			ast_channel_name(chan), dahdi_tech->type);
+		ast_channel_unlock(chan);
+		return 0;
+	}
+	if (ast_channel_has_audio_frame_or_monitor(chan)) {
+		ast_debug(2, "Channel '%s' has an active monitor, audiohook, or framehook.\n",
+			ast_channel_name(chan));
+		ast_channel_unlock(chan);
+		return 0;
+	}
+	pvt = ast_channel_tech_pvt(chan);
+	if (!pvt || !pvt->sig) {
+		/* No private; or signaling is for a pseudo channel. */
+		ast_channel_unlock(chan);
+		return 0;
+	}
+
+	is_capable = 1;
+	ast_mutex_lock(&pvt->lock);
+
+	if (pvt->callwaiting && pvt->callwaitingcallerid) {
+		/*
+		 * Call Waiting Caller ID requires DTMF detection to know if it
+		 * can send the CID spill.
+		 */
+		ast_debug(2, "Channel '%s' has call waiting caller ID enabled.\n",
+			ast_channel_name(chan));
+		is_capable = 0;
+	}
+
+	ast_mutex_unlock(&pvt->lock);
+	ast_channel_unlock(chan);
+
+	return is_capable;
+}
+
+/*!
+ * \internal
+ * \brief Check if a bridge is compatible with the bridging technology.
+ * \since 12.0.0
+ *
+ * \retval 0 if not compatible
+ * \retval non-zero if compatible
+ *
+ * \note On entry, bridge may or may not already be locked.
+ * However, it can be accessed as if it were locked.
+ */
+static int native_bridge_compatible(struct ast_bridge *bridge)
+{
+	struct ast_bridge_channel *cur;
+
+	/* We require two channels before even considering native bridging. */
+	if (bridge->num_channels != 2) {
+		ast_debug(1, "Bridge %s: Cannot use native DAHDI.  Must have two channels.\n",
+			bridge->uniqueid);
+		return 0;
+	}
+
+	AST_LIST_TRAVERSE(&bridge->channels, cur, entry) {
+		if (!native_bridge_is_capable(cur)) {
+			ast_debug(1, "Bridge %s: Cannot use native DAHDI.  Channel '%s' not compatible.\n",
+				bridge->uniqueid, ast_channel_name(cur->chan));
+			return 0;
+		}
+	}
+
+	return -1;
+}
+
+/*!
+ * \internal
+ * \brief Check if something changed on the channel.
+ * \since 12.0.0
+ *
+ * \param bridge_channel What to operate upon.
+ *
+ * \retval 0 Nothing changed.
+ * \retval -1 Something changed.
+ *
+ * \note On entry, bridge_channel->bridge is already locked.
+ */
+static int native_chan_changed(struct ast_bridge_channel *bridge_channel)
+{
+	struct native_pvt_chan *tech_pvt;
+	struct ast_channel *chan;
+	struct dahdi_pvt *pvt;
+	int idx = -1;
+
+	ast_assert(bridge_channel->tech_pvt != NULL);
+
+	tech_pvt = bridge_channel->tech_pvt;
+
+	chan = bridge_channel->chan;
+	ast_channel_lock(chan);
+	pvt = ast_channel_tech_pvt(chan);
+	if (tech_pvt->pvt == pvt) {
+		idx = dahdi_get_index(chan, pvt, 1);
+	}
+	ast_channel_unlock(chan);
+
+	if (/* Did chan get masqueraded or PRI change associated B channel? */
+		tech_pvt->pvt != pvt
+		/* Did the pvt active owner change? */
+		|| tech_pvt->owner != pvt->owner
+		/* Did the pvt three way call status change? */
+		|| tech_pvt->inthreeway != pvt->subs[SUB_REAL].inthreeway
+		/* Did the owner index change? */
+		|| tech_pvt->index != idx
+		/*
+		 * Did chan file descriptor change? (This seems redundant with
+		 * masquerade and active owner change checks.)
+		 */
+		|| tech_pvt->fd0 != ast_channel_fd(chan, 0)
+		/* Did chan state change? i.e. Did it stop ringing? */
+		|| (pvt->subs[SUB_REAL].owner
+			&& tech_pvt->state > -1
+			&& tech_pvt->state != ast_channel_state(pvt->subs[SUB_REAL].owner))) {
+		return -1;
+	}
+
+	return 0;
+}
+
+/*!
+ * \internal
+ * \brief Check if something changed on the bridge channels.
+ * \since 12.0.0
+ *
+ * \param bridge What to operate upon.
+ *
+ * \retval 0 Nothing changed.
+ * \retval -1 Something changed.
+ *
+ * \note On entry, bridge is already locked.
+ */
+static int native_bridge_changed(struct ast_bridge *bridge)
+{
+	struct ast_bridge_channel *cur;
+
+	AST_LIST_TRAVERSE(&bridge->channels, cur, entry) {
+		if (native_chan_changed(cur)) {
+			ast_debug(1, "Bridge %s: Something changed on channel '%s'.\n",
+				bridge->uniqueid, ast_channel_name(cur->chan));
+			return -1;
+		}
+	}
+	return 0;
+}
+
+/*!
+ * \internal
+ * \brief Write a frame into the bridging technology instance for a bridge.
+ * \since 12.0.0
+ *
+ * \note The bridge must be tolerant of bridge_channel being NULL.
+ *
+ * \retval 0 Frame accepted into the bridge.
+ * \retval -1 Frame needs to be deferred.
+ *
+ * \note On entry, bridge is already locked.
+ */
+static int native_bridge_write(struct ast_bridge *bridge, struct ast_bridge_channel *bridge_channel, struct ast_frame *frame)
+{
+	struct native_pvt_bridge *tech_pvt;
+
+	/*
+	 * When we are not native bridged by DAHDI, we are like a normal
+	 * 1-1 bridge.
+	 */
+
+	ast_assert(bridge->tech_pvt != NULL);
+
+	/* Recheck native bridging validity. */
+	tech_pvt = bridge->tech_pvt;
+	switch (frame->frametype) {
+	case AST_FRAME_VOICE:
+	case AST_FRAME_VIDEO:
+		if (!tech_pvt->connected) {
+			/* Don't try to start native mode on media frames. */
+			break;
+		}
+		if (native_bridge_changed(bridge)) {
+			native_request_stop(bridge);
+			native_request_start(bridge);
+			if (!tech_pvt->connected) {
+				break;
+			}
+		}
+
+		/*
+		 * Native bridge handles voice frames in hardware.  However, it
+		 * also passes the frames up to Asterisk anyway.  Discard the
+		 * media frames.
+		 */
+		return 0;
+	default:
+		if (!tech_pvt->connected) {
+			native_request_start(bridge);
+			break;
+		}
+		if (native_bridge_changed(bridge)) {
+			native_request_stop(bridge);
+			native_request_start(bridge);
+		}
+		break;
+	}
+
+	return ast_bridge_queue_everyone_else(bridge, bridge_channel, frame);
+}
+
+static struct ast_bridge_technology native_bridge = {
+	.name = "native_dahdi",
+	.capabilities = AST_BRIDGE_CAPABILITY_NATIVE,
+	.preference = AST_BRIDGE_PREFERENCE_BASE_NATIVE,
+	.create = native_bridge_create,
+	.start = native_bridge_start,
+	.stop = native_bridge_stop,
+	.destroy = native_bridge_destroy,
+	.join = native_bridge_join,
+	.leave = native_bridge_leave,
+	.suspend = native_bridge_suspend,
+	.unsuspend = native_bridge_unsuspend,
+	.compatible = native_bridge_compatible,
+	.write = native_bridge_write,
+};
+
+/*!
+ * \internal
+ * \brief Destroy the DAHDI native bridge support.
+ * \since 12.0.0
+ *
+ * \return Nothing
+ */
+void dahdi_native_unload(void)
+{
+	ast_bridge_technology_unregister(&native_bridge);
+	ast_format_cap_destroy(native_bridge.format_capabilities);
+}
+
+/*!
+ * \internal
+ * \brief Initialize the DAHDI native bridge support.
+ * \since 12.0.0
+ *
+ * \retval 0 on success.
+ * \retval -1 on error.
+ */
+int dahdi_native_load(struct ast_module *mod, const struct ast_channel_tech *tech)
+{
+	struct ast_format format;
+
+	dahdi_tech = tech;
+
+	native_bridge.format_capabilities = ast_format_cap_alloc();
+	if (!native_bridge.format_capabilities) {
+		return -1;
+	}
+
+	/*
+	 * This is used to make channels compatible with the bridge
+	 * itself not with each other.
+	 */
+	ast_format_cap_add(native_bridge.format_capabilities, ast_format_set(&format, AST_FORMAT_SLINEAR, 0));
+	ast_format_cap_add(native_bridge.format_capabilities, ast_format_set(&format, AST_FORMAT_ULAW, 0));
+	ast_format_cap_add(native_bridge.format_capabilities, ast_format_set(&format, AST_FORMAT_ALAW, 0));
+
+	return __ast_bridge_technology_register(&native_bridge, mod);
+}
diff --git a/channels/dahdi/bridge_native_dahdi.h b/channels/dahdi/bridge_native_dahdi.h
new file mode 100644
index 000000000..91e8d16b7
--- /dev/null
+++ b/channels/dahdi/bridge_native_dahdi.h
@@ -0,0 +1,47 @@
+/*
+ * Asterisk -- An open source telephony toolkit.
+ *
+ * Copyright (C) 2013 Digium, Inc.
+ *
+ * Richard Mudgett <rmudgett@digium.com>
+ *
+ * See http://www.asterisk.org for more information about
+ * the Asterisk project. Please do not directly contact
+ * any of the maintainers of this project for assistance;
+ * the project provides a web site, mailing lists and IRC
+ * channels for your use.
+ *
+ * This program is free software, distributed under the terms of
+ * the GNU General Public License Version 2. See the LICENSE file
+ * at the top of the source tree.
+ */
+
+/*!
+ * \file
+ * \brief Native DAHDI bridging support.
+ *
+ * \author Richard Mudgett <rmudgett@digium.com>
+ *
+ * See Also:
+ * \arg \ref AstCREDITS
+ */
+
+#ifndef _ASTERISK_BRIDGE_NATIVE_DAHDI_H
+#define _ASTERISK_BRIDGE_NATIVE_DAHDI_H
+
+#if defined(__cplusplus) || defined(c_plusplus)
+extern "C" {
+#endif
+
+/* ------------------------------------------------------------------- */
+
+void dahdi_native_unload(void);
+int dahdi_native_load(struct ast_module *mod, const struct ast_channel_tech *tech);
+
+/* ------------------------------------------------------------------- */
+
+#if defined(__cplusplus) || defined(c_plusplus)
+}
+#endif
+
+#endif	/* _ASTERISK_BRIDGE_NATIVE_DAHDI_H */
diff --git a/main/bridging.c b/main/bridging.c
index 0419ab1a3..132b7d4be 100644
--- a/main/bridging.c
+++ b/main/bridging.c
@@ -375,6 +375,10 @@ int ast_bridge_channel_queue_frame(struct ast_bridge_channel *bridge_channel, st
 		/* Drop non-deferable frames when suspended. */
 		return 0;
 	}
+	if (fr->frametype == AST_FRAME_NULL) {
+		/* "Accept" the frame and discard it. */
+		return 0;
+	}
 
 	dup = ast_frdup(fr);
 	if (!dup) {
@@ -427,6 +431,11 @@ int ast_bridge_queue_everyone_else(struct ast_bridge *bridge, struct ast_bridge_
 	struct ast_bridge_channel *cur;
 	int not_written = -1;
 
+	if (frame->frametype == AST_FRAME_NULL) {
+		/* "Accept" the frame and discard it. */
+		return 0;
+	}
+
 	AST_LIST_TRAVERSE(&bridge->channels, cur, entry) {
 		if (cur == bridge_channel) {
 			continue;
@@ -1243,10 +1252,6 @@ static void bridge_handle_trip(struct ast_bridge_channel *bridge_channel)
 		return;
 	}
 	switch (frame->frametype) {
-	case AST_FRAME_NULL:
-		/* Just discard it. */
-		ast_frfree(frame);
-		return;
 	case AST_FRAME_CONTROL:
 		switch (frame->subclass.integer) {
 		case AST_CONTROL_HANGUP: