Created doxygen documentation for PJNATH

git-svn-id: http://svn.pjsip.org/repos/pjproject/trunk@1110 74dad513-b988-da41-8d7b-12977e46ad98

11 files changed, 1143 insertions, 393 deletions

diff --git a/pjnath/include/pjnath/config.h b/pjnath/include/pjnath/config.h
index fc3e004e..3bc5afaf 100644
--- a/pjnath/include/pjnath/config.h
+++ b/pjnath/include/pjnath/config.h
@@ -27,7 +27,7 @@
 
 /**
  * @defgroup PJNATH_CONFIG Configuration
- * @ingroup PJNATH
+ * @brief Various compile time settings
  * @{
  */
 
@@ -36,28 +36,121 @@
  */
 
 /**
- * Maximum number of attributes in the STUN packet (for the old STUN
+ * Maximum number of attributes in the STUN packet (for the new STUN
  * library).
  *
  * Default: 16
  */
-#ifndef PJSTUN_MAX_ATTR
-#   define PJSTUN_MAX_ATTR			    16
+#ifndef PJ_STUN_MAX_ATTR
+#   define PJ_STUN_MAX_ATTR			    16
+#endif
+
+/**
+ * The default initial STUN round-trip time estimation (the RTO value
+ * in RFC 3489-bis), in miliseconds. 
+ * This value is used to control the STUN request 
+ * retransmit time. The initial value of retransmission interval 
+ * would be set to this value, and will be doubled after each
+ * retransmission.
+ */
+#ifndef PJ_STUN_RTO_VALUE
+#   define PJ_STUN_RTO_VALUE			    100
 #endif
 
 
 /**
- * Maximum number of attributes in the STUN packet (for the new STUN
- * library).
+ * The STUN transaction timeout value, in miliseconds.
+ * After the last retransmission is sent and if no response is received 
+ * after this time, the STUN transaction will be considered to have failed.
+ *
+ * The default value is 1600 miliseconds (as per RFC 3489-bis).
+ */
+#ifndef PJ_STUN_TIMEOUT_VALUE
+#   define PJ_STUN_TIMEOUT_VALUE		    1600
+#endif
+
+
+/**
+ * Maximum number of STUN retransmission count.
+ *
+ * Default: 7 (as per RFC 3489-bis)
+ */
+#ifndef PJ_STUN_MAX_RETRANSMIT_COUNT
+#   define PJ_STUN_MAX_RETRANSMIT_COUNT		    7
+#endif
+
+
+/**
+ * Maximum size of STUN message.
+ */
+#ifndef PJ_STUN_MAX_PKT_LEN
+#   define PJ_STUN_MAX_PKT_LEN			    512
+#endif
+
+
+/**
+ * Default STUN port as defined by RFC 3489.
+ */
+#define PJ_STUN_PORT				    3478
+
+
+
+/* **************************************************************************
+ * ICE CONFIGURATION
+ */
+
+/**
+ * Maximum number of ICE candidates.
  *
  * Default: 16
  */
-#ifndef PJ_STUN_MAX_ATTR
-#   define PJ_STUN_MAX_ATTR			    16
+#ifndef PJ_ICE_MAX_CAND
+#   define PJ_ICE_MAX_CAND			    16
+#endif
+
+
+/**
+ * Maximum number of candidates for each ICE stream transport component.
+ *
+ * Default: 8
+ */
+#ifndef PJ_ICE_ST_MAX_CAND
+#   define PJ_ICE_ST_MAX_CAND			    8
+#endif
+
+
+/**
+ * Maximum number of ICE components.
+ *
+ * Default: 8
+ */
+#ifndef PJ_ICE_MAX_COMP
+#   define PJ_ICE_MAX_COMP			    8
+#endif
+
+
+/**
+ * Maximum number of ICE checks.
+ *
+ * Default: 32
+ */
+#ifndef PJ_ICE_MAX_CHECKS
+#   define PJ_ICE_MAX_CHECKS			    32
 #endif
 
 
 /**
+ * Default timer interval (in miliseconds) for starting ICE periodic checks.
+ *
+ * Default: 20
+ */
+#ifndef PJ_ICE_TA_VAL
+#   define PJ_ICE_TA_VAL			    20
+#endif
+
+
+
+/**
  * @}
  */
 
diff --git a/pjnath/include/pjnath/errno.h b/pjnath/include/pjnath/errno.h
index c5a2afa5..cb470747 100644
--- a/pjnath/include/pjnath/errno.h
+++ b/pjnath/include/pjnath/errno.h
@@ -19,12 +19,16 @@
 #ifndef __PJNATH_ERRNO_H__
 #define __PJNATH_ERRNO_H__
 
+/**
+ * @file errno.h
+ * @brief PJNATH specific error codes
+ */
 
 #include <pj/errno.h>
 
 /**
  * @defgroup PJNATH_ERROR NAT Helper Library Error Codes
- * @ingroup PJNATH
+ * @brief PJNATH specific error code constants
  * @{
  */
 
diff --git a/pjnath/include/pjnath/ice.h b/pjnath/include/pjnath/ice.h
index cc8b7918..02c05882 100644
--- a/pjnath/include/pjnath/ice.h
+++ b/pjnath/include/pjnath/ice.h
@@ -21,7 +21,7 @@
 
 /**
  * @file ice.h
- * @brief ICE.
+ * @brief ICE session management
  */
 #include <pjnath/types.h>
 #include <pjnath/stun_session.h>
@@ -31,7 +31,6 @@
 /**
  * @defgroup PJNATH_ICE Interactive Connectivity Establishment (ICE)
  * @brief Interactive Connectivity Establishment (ICE)
- * @ingroup PJNATH
  */
 
 
@@ -39,10 +38,30 @@ PJ_BEGIN_DECL
 
 
 /**
- * @defgroup PJNATH_ICE_STREAM Transport Independent ICE Media Stream
- * @brief Transport Independent ICE Media Stream
+ * @defgroup PJNATH_ICE_SESSION ICE Session
+ * @brief Transport Independent ICE Session
  * @ingroup PJNATH_ICE
  * @{
+ *
+ * This module describes #pj_ice, a transport independent ICE session,
+ * part of PJNATH - the Open Source NAT helper library.
+ *
+ * An ICE session, represented by #pj_ice structure, is the lowest 
+ * abstraction of ICE in PJNATH, and it is used to perform and manage
+ * connectivity checks of transport address candidates <b>within a
+ * single media stream</b> (note: this differs from what is described
+ * in ICE draft, where an ICE session manages the whole media sessions
+ * rather than just a single stream).
+ *
+ * The ICE session described here is independent from any transports,
+ * meaning that the actual network I/O for this session would have to
+ * be performed by the application, or higher layer abstraction. 
+ * Using this framework, application would give any incoming packets to
+ * the ICE session, and it would provide the ICE session with a callback
+ * to send outgoing message.
+ *
+ * For higher abstraction of ICE where transport is included, please 
+ * see \ref PJNATH_ICE_STREAM_TRANSPORT.
  */
 
 /**
@@ -50,105 +69,318 @@ PJ_BEGIN_DECL
  */
 typedef enum pj_ice_cand_type
 {
-    PJ_ICE_CAND_TYPE_HOST,
-    PJ_ICE_CAND_TYPE_SRFLX,
-    PJ_ICE_CAND_TYPE_PRFLX,
-    PJ_ICE_CAND_TYPE_RELAYED
+    PJ_ICE_CAND_TYPE_HOST,	/**< ICE host candidate.		*/
+    PJ_ICE_CAND_TYPE_SRFLX,	/**< ICE server reflexive candidate.	*/
+    PJ_ICE_CAND_TYPE_PRFLX,	/**< ICE peer reflexive candidate.	*/
+    PJ_ICE_CAND_TYPE_RELAYED	/**< ICE relayed candidate.		*/
 } pj_ice_cand_type;
 
+
 /**
- *
+ * This enumeration describes the default preference for the ICE
+ * candidate types as described by ICE standard.
  */
 enum pj_ice_type_pref
 {
-    PJ_ICE_HOST_PREF	    = 126,
-    PJ_ICE_SRFLX_PREF	    = 100,
-    PJ_ICE_PRFLX_PREF	    = 110,
-    PJ_ICE_RELAYED_PREF	    = 0
+    PJ_ICE_HOST_PREF	    = 126,  /**< Preference value for host.	*/
+    PJ_ICE_SRFLX_PREF	    = 100,  /**< Preference value for SRFLX.	*/
+    PJ_ICE_PRFLX_PREF	    = 110,  /**< Preference value for PRFLX	*/
+    PJ_ICE_RELAYED_PREF	    = 0	    /**< Preference value for relay	*/
 };
 
+/** Forward declaration for pj_ice */
 typedef struct pj_ice pj_ice;
+
+/** Forward declaration for pj_ice_check */
 typedef struct pj_ice_check pj_ice_check;
 
-#define PJ_ICE_MAX_CAND	    16
-#define PJ_ICE_MAX_COMP	    8
-#define PJ_ICE_MAX_CHECKS   32
-#define PJ_ICE_TA_VAL	    20
 
 /**
- * ICE component
+ * This structure describes ICE component. 
+ * A media stream may require multiple components, each of which has 
+ * to work for the media stream as a whole to work.  For media streams
+ * based on RTP, there are two components per media stream - one for RTP,
+ * and one for RTCP.
  */
 typedef struct pj_ice_comp
 {
+    /**
+     * The pointer to ICE check which was nominated for this component.
+     * The value will be NULL if a nominated check has not been found
+     * for this component.
+     */
     pj_ice_check	*valid_check;
+
 } pj_ice_comp;
 
 
 /**
  * This structure describes an ICE candidate.
+ * ICE candidate is a transport address that is to be tested by ICE
+ * procedures in order to determine its suitability for usage for
+ * receipt of media.  Candidates also have properties - their type
+ * (server reflexive, relayed or host), priority, foundation, and
+ * base.
  */
 typedef struct pj_ice_cand
 {
+    /**
+     * The component ID of this candidate. Note that component IDs starts
+     * with one for RTP and two for RTCP. In other words, it's not zero
+     * based.
+     */
     pj_uint32_t		 comp_id;
+
+    /**
+     * The candidate type, as described in #pj_ice_cand_type enumeration.
+     */
     pj_ice_cand_type	 type;
+
+    /**
+     * The foundation string, which is an identifier which value will be
+     * equivalent for two candidates that are of the same type, share the 
+     * same base, and come from the same STUN server. The foundation is 
+     * used to optimize ICE performance in the Frozen algorithm.
+     */
     pj_str_t		 foundation;
+
+    /**
+     * The candidate's priority, a 32-bit unsigned value which value will be
+     * calculated by the ICE session when a candidate is registered to the
+     * ICE session.
+     */
     pj_uint32_t		 prio;
+
+    /**
+     * IP address of this candidate. For host candidates, this represents
+     * the local address of the socket. For reflexive candidates, the value
+     * will be the public address allocated in NAT router for the host
+     * candidate and as reported in MAPPED-ADDRESS or XOR-MAPPED-ADDRESS
+     * attribute of STUN Binding request. For relayed candidate, the value 
+     * will be the address allocated in the TURN server by STUN Allocate
+     * request.
+     */
     pj_sockaddr		 addr;
+
+    /**
+     * Base address of this candidate. "Base" refers to the address an agent 
+     * sends from for a particular candidate.  For host candidates, the base
+     * is the same as the host candidate itself. For reflexive candidates, 
+     * the base is the local IP address of the socket. For relayed candidates,
+     * the base address is the transport address allocated in the TURN server
+     * for this candidate.
+     */
     pj_sockaddr		 base_addr;
+
+    /**
+     * Related address, which is used for informational only and is not used
+     * in any way by the ICE session.
+     */
     pj_sockaddr		 rel_addr;
+
+    /**
+     * The STUN session to be used to send and receive STUN messages for this
+     * candidate.
+     */
     pj_stun_session	*stun_sess;
+
 } pj_ice_cand;
 
+
+/**
+ * This enumeration describes the state of ICE check.
+ */
 typedef enum pj_ice_check_state
 {
+    /**
+     * A check for this pair hasn't been performed, and it can't
+     * yet be performed until some other check succeeds, allowing this
+     * pair to unfreeze and move into the Waiting state.
+     */
     PJ_ICE_CHECK_STATE_FROZEN,
+
+    /**
+     * A check has not been performed for this pair, and can be
+     * performed as soon as it is the highest priority Waiting pair on
+     * the check list.
+     */
     PJ_ICE_CHECK_STATE_WAITING,
+
+    /**
+     * A check has not been performed for this pair, and can be
+     * performed as soon as it is the highest priority Waiting pair on
+     * the check list.
+     */
     PJ_ICE_CHECK_STATE_IN_PROGRESS,
+
+    /**
+     * A check has not been performed for this pair, and can be
+     * performed as soon as it is the highest priority Waiting pair on
+     * the check list.
+     */
     PJ_ICE_CHECK_STATE_SUCCEEDED,
+
+    /**
+     * A check for this pair was already done and failed, either
+     * never producing any response or producing an unrecoverable failure
+     * response.
+     */
     PJ_ICE_CHECK_STATE_FAILED
+
 } pj_ice_check_state;
 
 
+/**
+ * This structure describes an ICE connectivity check. An ICE check
+ * contains a candidate pair, and will involve sending STUN Binding 
+ * Request transaction for the purposes of verifying connectivity. 
+ * A check is sent from the local candidate to the remote candidate 
+ * of a candidate pair.
+ */
 struct pj_ice_check
 {
+    /**
+     * Pointer to local candidate entry of this check.
+     */
     pj_ice_cand		*lcand;
+
+    /**
+     * Pointer to remote candidate entry of this check.
+     */
     pj_ice_cand		*rcand;
 
+    /**
+     * Check priority.
+     */
     pj_uint64_t		 prio;
+
+    /**
+     * Connectivity check state.
+     */
     pj_ice_check_state	 state;
+
+    /**
+     * STUN transmit data containing STUN Binding request that was sent 
+     * as part of this check. The value will only be set when this check 
+     * has a pending transaction, and is used to cancel the transaction
+     * when other check has succeeded.
+     */
     pj_stun_tx_data	*tdata;
+
+    /**
+     * Flag to indicate whether this check is nominated. A nominated check
+     * contains USE-CANDIDATE attribute in its STUN Binding request.
+     */
     pj_bool_t		 nominated;
+
+    /**
+     * When the check failed, this will contain the failure status of the
+     * STUN transaction.
+     */
     pj_status_t		 err_code;
 };
 
 
+/**
+ * This enumeration describes ICE checklist state.
+ */
 typedef enum pj_ice_checklist_state
 {
+    /**
+     * The checklist is not yet running.
+     */
     PJ_ICE_CHECKLIST_ST_IDLE,
+
+    /**
+     * In this state, ICE checks are still in progress for this
+     * media stream.
+     */
     PJ_ICE_CHECKLIST_ST_RUNNING,
+
+    /**
+     * In this state, ICE checks have completed for this media stream,
+     * either successfully or with failure.
+     */
     PJ_ICE_CHECKLIST_ST_COMPLETED
+
 } pj_ice_checklist_state;
 
+
+/**
+ * This structure represents ICE check list, that is an ordered set of 
+ * candidate pairs that an agent will use to generate checks.
+ */
 typedef struct pj_ice_checklist
 {
+    /**
+     * The checklist state.
+     */
     pj_ice_checklist_state   state;
+
+    /**
+     * Number of candidate pairs (checks).
+     */
     unsigned		     count;
+
+    /**
+     * Array of candidate pairs (checks).
+     */
     pj_ice_check	     checks[PJ_ICE_MAX_CHECKS];
+
+    /**
+     * A timer used to perform periodic check for this checklist.
+     */
     pj_timer_entry	     timer;
+
 } pj_ice_checklist;
 
 
 /**
- * ICE sock callback.
+ * This structure contains callbacks that will be called by the ICE
+ * session.
  */
 typedef struct pj_ice_cb
 {
+    /**
+     * An optional callback that will be called by the ICE session when
+     * ICE negotiation has completed, successfully or with failure.
+     *
+     * @param ice	    The ICE session.
+     * @param status	    Will contain PJ_SUCCESS if ICE negotiation is
+     *			    successful, or some error code.
+     */
     void	(*on_ice_complete)(pj_ice *ice, pj_status_t status);
+
+    /**
+     * A mandatory callback which will be called by the ICE session when
+     * it needs to send outgoing STUN packet. 
+     *
+     * @param ice	    The ICE session.
+     * @param comp_id	    ICE component ID.
+     * @param cand_id	    ICE candidate ID.
+     * @param pkt	    The STUN packet.
+     * @param size	    The size of the packet.
+     * @param dst_addr	    Packet destination address.
+     * @param dst_addr_len  Length of destination address.
+     */
     pj_status_t (*on_tx_pkt)(pj_ice *ice, unsigned comp_id, 
 			     unsigned cand_id,
 			     const void *pkt, pj_size_t size,
 			     const pj_sockaddr_t *dst_addr,
 			     unsigned dst_addr_len);
+
+    /**
+     * A mandatory callback which will be called by the ICE session when
+     * it receives packet which is not part of ICE negotiation.
+     *
+     * @param ice	    The ICE session.
+     * @param comp_id	    ICE component ID.
+     * @param pkt	    The whole packet.
+     * @param size	    Size of the packet.
+     * @param src_addr	    Source address where this packet was received 
+     *			    from.
+     * @param src_addr_len  The length of source address.
+     */
     void	(*on_rx_data)(pj_ice *ice, unsigned comp_id,
 			      void *pkt, pj_size_t size,
 			      const pj_sockaddr_t *src_addr,
@@ -156,59 +388,110 @@ typedef struct pj_ice_cb
 } pj_ice_cb;
 
 
+/**
+ * This enumeration describes ICE role.
+ */
 typedef enum pj_ice_role
 {
+    /**
+     * The ICE agent is in controlled role.
+     */
     PJ_ICE_ROLE_CONTROLLED,
+
+    /**
+     * The ICE agent is in controlling role.
+     */
     PJ_ICE_ROLE_CONTROLLING
+
 } pj_ice_role;
 
+
 /**
- * ICE structure.
+ * This structure describes the ICE session. For this version of PJNATH,
+ * an ICE session corresponds to a single media stream (unlike the ICE
+ * session described in the ICE standard where an ICE session covers the
+ * whole media and may consist of multiple media streams). The decision
+ * to support only a single media session was chosen for simplicity,
+ * while still allowing application to utilize multiple media streams by
+ * creating multiple ICE sessions, one for each media stream.
  */
 struct pj_ice
 {
-    char		obj_name[PJ_MAX_OBJ_NAME];
+    char		obj_name[PJ_MAX_OBJ_NAME];  /**< Object name.	    */
 
-    pj_pool_t		*pool;
-    void		*user_data;
-    pj_mutex_t		*mutex;
-    pj_ice_role		 role;
-    pj_bool_t		 is_complete;
-    pj_status_t		 ice_status;
-    pj_ice_cb		 cb;
+    pj_pool_t		*pool;			    /**< Pool instance.	    */
+    void		*user_data;		    /**< App. data.	    */
+    pj_mutex_t		*mutex;			    /**< Mutex.		    */
+    pj_ice_role		 role;			    /**< ICE role.	    */
+    pj_bool_t		 is_complete;		    /**< Complete?	    */
+    pj_status_t		 ice_status;		    /**< Error status.	    */
+    pj_ice_cb		 cb;			    /**< Callback.	    */
 
-    pj_stun_config	 stun_cfg;
+    pj_stun_config	 stun_cfg;		    /**< STUN settings.	    */
 
     /* STUN credentials */
-    pj_str_t		 tx_ufrag;
-    pj_str_t		 tx_uname;
-    pj_str_t		 tx_pass;
-    pj_str_t		 rx_ufrag;
-    pj_str_t		 rx_uname;
-    pj_str_t		 rx_pass;
+    pj_str_t		 tx_ufrag;		    /**< Remote ufrag.	    */
+    pj_str_t		 tx_uname;		    /**< Uname for TX.	    */
+    pj_str_t		 tx_pass;		    /**< Remote password.   */
+    pj_str_t		 rx_ufrag;		    /**< Local ufrag.	    */
+    pj_str_t		 rx_uname;		    /**< Uname for RX	    */
+    pj_str_t		 rx_pass;		    /**< Local password.    */
 
     /* Components */
-    unsigned		 comp_cnt;
-    pj_ice_comp		 comp[PJ_ICE_MAX_COMP];
+    unsigned		 comp_cnt;		    /**< # of components.   */
+    pj_ice_comp		 comp[PJ_ICE_MAX_COMP];	    /**< Component array    */
 
     /* Local candidates */
-    unsigned		 lcand_cnt;
-    pj_ice_cand		 lcand[PJ_ICE_MAX_CAND];
+    unsigned		 lcand_cnt;		    /**< # of local cand.   */
+    pj_ice_cand		 lcand[PJ_ICE_MAX_CAND];    /**< Array of cand.	    */
 
     /* Remote candidates */
-    unsigned		 rcand_cnt;
-    pj_ice_cand		 rcand[PJ_ICE_MAX_CAND];
+    unsigned		 rcand_cnt;		    /**< # of remote cand.  */
+    pj_ice_cand		 rcand[PJ_ICE_MAX_CAND];    /**< Array of cand.	    */
 
     /* Checklist */
-    pj_ice_checklist	 clist;
+    pj_ice_checklist	 clist;			    /**< Active checklist   */
     
     /* Valid list */
-    pj_ice_checklist	 valid_list;
+    pj_ice_checklist	 valid_list;		    /**< Valid list.	    */
 };
 
+
+/**
+ * This is a utility function to retrieve the string name for the
+ * particular candidate type.
+ *
+ * @param type	    Candidate type.
+ *
+ * @return	    The string representation of the candidate type.
+ */
 PJ_DECL(const char*) pj_ice_get_cand_type_name(pj_ice_cand_type type);
 
 
+/**
+ * Create ICE session with the specified role and number of components.
+ * Application would typically need to create an ICE session before
+ * sending an offer or upon receiving one. After the session is created,
+ * application can register candidates to the ICE session by calling
+ * #pj_ice_add_cand() function.
+ *
+ * @param stun_cfg	The STUN configuration settings, containing among
+ *			other things the timer heap instance to be used
+ *			by the ICE session.
+ * @param name		Optional name to identify this ICE instance in
+ *			the log file.
+ * @param role		ICE role.
+ * @param comp_cnt	Number of components.
+ * @param cb		ICE callback.
+ * @param local_ufrag	Optional string to be used as local username to
+ *			authenticate incoming STUN binding request. If
+ *			the value is NULL, a random string will be 
+ *			generated.
+ * @param local_passwd	Optional string to be used as local password.
+ * @param p_ice		Pointer to receive the ICE session instance.
+ *
+ * @return		PJ_SUCCESS if ICE session is created successfully.
+ */
 PJ_DECL(pj_status_t) pj_ice_create(pj_stun_config *stun_cfg,
 				   const char *name,
 				   pj_ice_role role,
@@ -217,7 +500,34 @@ PJ_DECL(pj_status_t) pj_ice_create(pj_stun_config *stun_cfg,
 				   const pj_str_t *local_ufrag,
 				   const pj_str_t *local_passwd,
 				   pj_ice **p_ice);
+
+/**
+ * Destroy ICE session.
+ *
+ * @param ice		ICE session instance.
+ *
+ * @return		PJ_SUCCESS on success.
+ */
 PJ_DECL(pj_status_t) pj_ice_destroy(pj_ice *ice);
+
+
+/**
+ * Add a candidate to this ICE session. 
+ *
+ * @param ice		ICE session instance.
+ * @param comp_id	Component ID of this candidate.
+ * @param type		Candidate type.
+ * @param local_pref	Local preference for this candidate, which
+ *			normally should be set to 65535.
+ * @param foundation	Foundation identification.
+ * @param addr		The candidate address.
+ * @param base_addr	The candidate's base address.
+ * @param rel_addr	Optional related address.
+ * @param addr_len	Length of addresses.
+ * @param p_cand_id	Optional pointer to receive the candidate ID.
+ *
+ * @return		PJ_SUCCESS if candidate is successfully added.
+ */
 PJ_DECL(pj_status_t) pj_ice_add_cand(pj_ice *ice,
 				     unsigned comp_id,
 				     pj_ice_cand_type type,
@@ -227,23 +537,101 @@ PJ_DECL(pj_status_t) pj_ice_add_cand(pj_ice *ice,
 				     const pj_sockaddr_t *base_addr,
 				     const pj_sockaddr_t *rel_addr,
 				     int addr_len,
-				     unsigned *cand_id);
+				     unsigned *p_cand_id);
 
+/**
+ * Find default candidate for the specified component ID, using this
+ * rule:
+ *  - if the component has a successful candidate pair, then the
+ *    local candidate of this pair will be returned.
+ *  - otherwise a relay, reflexive, or host candidate will be selected 
+ *    on that specified order.
+ *
+ * @param ice		The ICE session instance.
+ * @param comp_id	The component ID.
+ * @param p_cand_id	Pointer to receive the candidate ID.
+ *
+ * @return		PJ_SUCCESS if a candidate has been selected.
+ */
 PJ_DECL(pj_status_t) pj_ice_find_default_cand(pj_ice *ice,
 					      unsigned comp_id,
-					      int *cand_id);
+					      int *p_cand_id);
 
+/**
+ * Pair the local and remote candidates to create check list. Application
+ * typically would call this function after receiving SDP containing ICE
+ * candidates from the remote host (either upon receiving the initial
+ * offer, for UAS, or upon receiving the answer, for UAC).
+ *
+ * Note that ICE connectivity check will not start until application calls
+ * #pj_ice_start_check().
+ *
+ * @param ice		ICE session instance.
+ * @param rem_ufrag	Remote ufrag, as seen in the SDP received from 
+ *			the remote agent.
+ * @param rem_passwd	Remote password, as seen in the SDP received from
+ *			the remote agent.
+ * @param rem_cand_cnt	Number of remote candidates.
+ * @param rem_cand	Remote candidate array. Remote candidates are
+ *			gathered from the SDP received from the remote 
+ *			agent.
+ *
+ * @return		PJ_SUCCESS or the appropriate error code.
+ */
 PJ_DECL(pj_status_t) pj_ice_create_check_list(pj_ice *ice,
 					      const pj_str_t *rem_ufrag,
 					      const pj_str_t *rem_passwd,
 					      unsigned rem_cand_cnt,
 					      const pj_ice_cand rem_cand[]);
+
+/**
+ * Start ICE periodic check. This function will return immediately, and
+ * application will be notified about the connectivity check status in
+ * #pj_ice_cb callback.
+ *
+ * @param ice		The ICE session instance.
+ *
+ * @return		PJ_SUCCESS or the appropriate error code.
+ */
 PJ_DECL(pj_status_t) pj_ice_start_check(pj_ice *ice);
 
+
+/**
+ * Send data using this ICE session. If ICE checks have not produced a
+ * valid check for the specified component ID, this function will return
+ * with failure. Otherwise ICE session will send the packet to remote
+ * destination using the nominated local candidate for the specified
+ * component.
+ *
+ * @param ice		The ICE session.
+ * @param comp_id	Component ID.
+ * @param data		The data or packet to be sent.
+ * @param data_len	Size of data or packet, in bytes.
+ *
+ * @return		PJ_SUCCESS if data is sent successfully.
+ */
 PJ_DECL(pj_status_t) pj_ice_send_data(pj_ice *ice,
 				      unsigned comp_id,
 				      const void *data,
 				      pj_size_t data_len);
+
+/**
+ * Report the arrival of packet to the ICE session. Since ICE session
+ * itself doesn't have any transports, it relies on application or
+ * higher layer component to give incoming packets to the ICE session.
+ * If the packet is not a STUN packet, this packet will be given back
+ * to application via \a on_rx_data() callback in #pj_ice_cb.
+ *
+ * @param ice		The ICE session.
+ * @param comp_id	Component ID.
+ * @param cand_id	Candidate ID.
+ * @param pkt		Incoming packet.
+ * @param pkt_size	Size of incoming packet.
+ * @param src_addr	Source address of the packet.
+ * @param src_addr_len	Length of the address.
+ *
+ * @return		PJ_SUCCESS or the appropriate error code.
+ */
 PJ_DECL(pj_status_t) pj_ice_on_rx_pkt(pj_ice *ice,
 				      unsigned comp_id,
 				      unsigned cand_id,
diff --git a/pjnath/include/pjnath/ice_stream_transport.h b/pjnath/include/pjnath/ice_stream_transport.h
index c42476b4..0403d841 100644
--- a/pjnath/include/pjnath/ice_stream_transport.h
+++ b/pjnath/include/pjnath/ice_stream_transport.h
@@ -21,8 +21,8 @@
 
 
 /**
- * @file ice_mt.h
- * @brief ICE Media Transport.
+ * @file ice_stream_transport.h
+ * @brief ICE Stream Transport
  */
 #include <pjnath/ice.h>
 #include <pjlib-util/resolver.h>
@@ -37,114 +37,427 @@ PJ_BEGIN_DECL
  * @brief Transport for media stream using ICE
  * @ingroup PJNATH_ICE
  * @{
+ *
+ * This module describes ICE stream transport, as represented by #pj_ice_st
+ * structure, and is part of PJNATH - the Open Source NAT traversal helper
+ * library.
+ *
+ * ICE stream transport, as represented by #pj_ice_st structure, is an ICE
+ * capable component for transporting media within a media stream. 
+ * It consists of one or more transport sockets (typically two for RTP
+ * based communication - one for RTP and one for RTCP), and an 
+ * \ref PJNATH_ICE_SESSION for performing connectivity checks among the.
+ * various candidates of the transport addresses.
+ *
+ * \section PJNATH_ICE_STREAM_TRANSPORT_USING Using the ICE Stream Transport
+ *
+ * Application may use the ICE stream transport in two ways:
+ *  - it can create the ICE stream transports once during application 
+ *    initialization and keep them alive throughout application lifetime, or
+ *  - it can create and destroy the ICE stream transport as needed everytime 
+ *     a call is made and destroyed. 
+ *
+ * Keeping the ICE stream transport alive throughout
+ * application's lifetime is normally preferable, as initializing the
+ * ICE stream transport may incur delay because the ICE stream transport
+ * would need to communicate with the STUN/TURN server to get the
+ * server reflexive and relayed candidates for the transports.
+ *
+ * Regardless of which usage scenario is being used, the ICE stream
+ * transport is capable for restarting the ICE session being used and to
+ * send STUN keep-alives for its STUN server reflexive and relayed
+ * candidates.
+ *
+ * \subsection PJNATH_ICE_ST_TRA_INIT Stream Transport Initialization
+ *
+ * Application creates the ICE stream transport by calling 
+ * #pj_ice_st_create() function.
+ *
+ * After the ICE stream transport is created, application may set up the
+ * STUN servers to be used to obtain STUN server reflexive and relayed
+ * candidate, by calling #pj_ice_st_set_stun_domain() or 
+ * #pj_ice_st_set_stun_srv(). Then it has to create each component by
+ * calling #pj_ice_st_create_comp(); this would create an actual socket
+ * which listens to the specified local address, and it would also
+ * perform lookup to find various transport address candidates for this
+ * socket.
+ * 
+ * \subsection PJNATH_ICE_ST_TRA_INIT_ICE ICE Session Initialization
+ *
+ * When application is about to send an offer containing ICE capability,
+ * or when it receives an offer containing ICE capability, it would
+ * create the ICE session by calling #pj_ice_st_init_ice(). This would
+ * register all transport address aliases for each component to the ICE
+ * session as candidates. After this application can enumerate all local
+ * candidates by calling #pj_ice_st_enum_cands(), and encode these
+ * candidates in the SDP to be sent to remote agent.
+ *
+ * \subsection PJNATH_ICE_ST_TRA_START Starting Connectivity Checks
+ *
+ * Once application receives the SDP from remote, it can start ICE
+ * connectivity checks by calling #pj_ice_st_start_ice(), specifying
+ * the username, password, and candidates of the remote agent. The ICE
+ * session/transport will then notify the application via the callback
+ * when ICE connectivity checks completes, either successfully or with
+ * failure.
+ *
+ * \subsection PJNATH_ICE_ST_TRA_STOP Stopping ICE Session
+ *
+ * Once the call is terminated, application no longer needs to keep the
+ * ICE session, so it should call #pj_ice_st_stop_ice() to destroy the
+ * ICE session within this ICE stream transport. Note that this WILL NOT
+ * destroy the sockets/transports, it only destroys the ICE session
+ * within this ICE stream transport.
+ *
+ * \subsection PJNATH_ICE_ST_TRA_RESTART Restarting ICE Session
+ *
+ * When a new call is made, application can repeat the above
+ * #pj_ice_st_init_ice() to #pj_ice_st_stop_ice() cycle for the new call,
+ * using this same ICE stream transport.
+ *
+ * \subsection PJNATH_ICE_ST_TRA_DESTROY Destroying ICE Stream Transport
+ *
+ * Finally, when the ICE stream transport itself is no longer needed,
+ * for example when the application quits, application should call
+ * #pj_ice_st_destroy() to release back all resources allocated by this
+ * ICE stream transport.
+ *
  */
 
+/** Forward declaration for ICE stream transport. */
 typedef struct pj_ice_st pj_ice_st;
 
+/** 
+ * This structure contains callbacks that will be called by the 
+ * ICE stream transport.
+ */
 typedef struct pj_ice_st_cb
 {
+    /**
+     * This callback will be called when the ICE transport receives
+     * incoming packet from the sockets which is not related to ICE
+     * (for example, normal RTP/RTCP packet destined for application).
+     *
+     * @param ice_st	    The ICE stream transport.
+     * @param comp_id	    The component ID.
+     * @param pkt	    The packet.
+     * @param size	    Size of the packet.
+     * @param src_addr	    Source address of the packet.
+     * @param src_addr_len  Length of the source address.
+     */
     void    (*on_rx_data)(pj_ice_st *ice_st,
 			  unsigned comp_id, 
 			  void *pkt, pj_size_t size,
 			  const pj_sockaddr_t *src_addr,
 			  unsigned src_addr_len);
+
+    /**
+     * This callback will be called when ICE checks have completed.
+     * This callback is optional.
+     * 
+     * @param ice_st	    The ICE stream transport.
+     * @param status	    The ICE connectivity check status.
+     */
     void    (*on_ice_complete)(pj_ice_st *ice_st, 
 			       pj_status_t status);
 
 } pj_ice_st_cb;
 
 
-#ifndef PJ_ICE_ST_MAX_ALIASES
-#   define PJ_ICE_ST_MAX_ALIASES	8
-#endif
-
+/**
+ * Various flags that can be specified when creating a component with
+ * #pj_ice_st_create_comp(). These options may be combined together
+ * with bitmask operation.
+ */
 enum pj_ice_st_option
 {
+    /**
+     * If this option is specified, only a listening socket will be
+     * created for the component, and no candidate will be added to
+     * the component. Application must add the component manually
+     * by inspecting the socket and transport address of the component.
+     */
     PJ_ICE_ST_OPT_DONT_ADD_CAND = 1,
+
+    /**
+     * If this option is specified, then no STUN reflexive candidate
+     * will be added to the component.
+     */
     PJ_ICE_ST_OPT_DISABLE_STUN	= 2,
+
+    /**
+     * If this option is specified, then no STUN relay candidate
+     * will be added to the component.
+     */
     PJ_ICE_ST_OPT_DISABLE_RELAY	= 4,
+
+    /**
+     * If this option is specified, then when the function fails to
+     * bind the socket to the specified port, it WILL NOT try to
+     * bind the socket to the next available port.
+     *
+     * If this option is NOT specified, then the function will try to
+     * bind the socket to next port+2, repetitively until the socket
+     * is bound successfully.
+     */
     PJ_ICE_ST_OPT_NO_PORT_RETRY	= 8,
 };
 
 
+/**
+ * This structure describes ICE stream transport candidate. A "candidate"
+ * in ICE stream transport can be viewed as alias transport address
+ * for the socket.
+ */
 typedef struct pj_ice_st_cand
 {
+    /**
+     * Candidate type.
+     */
     pj_ice_cand_type	type;
+
+    /** 
+     * Status of this candidate. This status is useful for ICE reflexive
+     * and relay candidate, where the address needs to be resolved 
+     * asynchronously by sending STUN request to STUN server.
+     *
+     * The value will be PJ_SUCCESS if candidate address has been resolved
+     * successfully, PJ_EPENDING when the address resolution process is
+     * in progress, or other value when the address resolution has
+     * completed with failure.
+     */
     pj_status_t		status;
+
+    /**
+     * The candidate transport address.
+     */
     pj_sockaddr		addr;
-    int			cand_id;
+
+    /**
+     * The ICE session candidate ID after this candidate has been registered
+     * to an ICE session. Before ICE session is created, or after ICE
+     * session has been destroyed, the value will be -1.
+     */
+    int			ice_cand_id;
+
+    /**
+     * Local preference value, which typically is 65535.
+     */
     pj_uint16_t		local_pref;
+
+    /**
+     * Foundation associated with this candidate, which value normally will be
+     * calculated by the function.
+     */
     pj_str_t		foundation;
+
 } pj_ice_st_cand;
 
 
+/**
+ * This structure describes an ICE stream transport component. A component
+ * in ICE stream transport typically corresponds to a single socket created
+ * for this component, and bound to a specific transport address. This
+ * component may have multiple alias addresses, for example one alias 
+ * address for each interfaces in multi-homed host, another for server
+ * reflexive alias, and another for relayed alias. For each transport
+ * address alias, an ICE stream transport candidate (#pj_ice_st_cand) will
+ * be created, and these candidates will eventually registered to the ICE
+ * session.
+ */
 typedef struct pj_ice_st_comp
 {
-    pj_ice_st		*ice_st;
-    unsigned		 comp_id;
-    pj_uint32_t		 options;
-    pj_sock_t		 sock;
+    pj_ice_st		*ice_st;	/**< ICE stream transport.	*/
+    unsigned		 comp_id;	/**< Component ID.		*/
+    pj_uint32_t		 options;	/**< Option flags.		*/
+    pj_sock_t		 sock;		/**< Socket descriptor.		*/
 
-    pj_stun_session	*stun_sess;
+    pj_stun_session	*stun_sess;	/**< STUN session.		*/
 
-    pj_sockaddr		 local_addr;
+    pj_sockaddr		 local_addr;	/**< Local/base address.	*/
 
-    unsigned		 pending_cnt;
-    pj_status_t		 last_status;
+    unsigned		 pending_cnt;	/**< Pending resolution cnt.	*/
+    pj_status_t		 last_status;	/**< Last status.		*/
 
-    unsigned		 cand_cnt;
-    pj_ice_st_cand	 cand_list[PJ_ICE_ST_MAX_ALIASES];
-    int			 default_cand;
+    unsigned		 cand_cnt;	/**< # of candidates/aliaes.	*/
+    pj_ice_st_cand	 cand_list[PJ_ICE_ST_MAX_CAND];	/**< Cand array	*/
+    int			 default_cand;	/**< Default candidate selected	*/
 
-    pj_ioqueue_key_t	*key;
-    pj_uint8_t		 pkt[1500];
-    pj_ioqueue_op_key_t	 read_op;
-    pj_ioqueue_op_key_t	 write_op;
-    pj_sockaddr		 src_addr;
-    int			 src_addr_len;
+    pj_ioqueue_key_t	*key;		/**< ioqueue key.		*/
+    pj_uint8_t		 pkt[1500];	/**< Incoming packet buffer.	*/
+    pj_ioqueue_op_key_t	 read_op;	/**< ioqueue read operation key	*/
+    pj_ioqueue_op_key_t	 write_op;	/**< ioqueue write op. key	*/
+    pj_sockaddr		 src_addr;	/**< source packet address buf.	*/
+    int			 src_addr_len;	/**< length of src addr. buf.	*/
 
 } pj_ice_st_comp;
 
 
+/**
+ * This structure represents the ICE stream transport.
+ */
 struct pj_ice_st
 {
-    char		     obj_name[PJ_MAX_OBJ_NAME];
-    pj_pool_t		    *pool;
-    void		    *user_data;
-    pj_stun_config	     stun_cfg;
-    pj_ice_st_cb	     cb;
+    char		     obj_name[PJ_MAX_OBJ_NAME];	/**< Log ID.	*/
+
+    pj_pool_t		    *pool;	/**< Pool used by this object.	*/
+    void		    *user_data;	/**< Application data.		*/
+    pj_stun_config	     stun_cfg;	/**< STUN settings.		*/
+    pj_ice_st_cb	     cb;	/**< Application callback.	*/
 
-    pj_ice		    *ice;
+    pj_ice		    *ice;	/**< ICE session.		*/
 
-    unsigned		     comp_cnt;
-    pj_ice_st_comp	   **comp;
+    unsigned		     comp_cnt;	/**< Number of components.	*/
+    pj_ice_st_comp	   **comp;	/**< Components array.		*/
 
-    pj_dns_resolver	    *resolver;
-    pj_bool_t		     has_resolver_job;
-    pj_sockaddr_in	     stun_srv;
-    pj_sockaddr_in	     turn_srv;
+    pj_dns_resolver	    *resolver;	/**< The resolver instance.	*/
+    pj_bool_t		     has_rjob;	/**< Has pending resolve?	*/
+    pj_sockaddr_in	     stun_srv;	/**< STUN server address.	*/
+    pj_sockaddr_in	     turn_srv;	/**< TURN server address.	*/
 };
 
 
+/**
+ * Create the ICE stream transport containing the specified number of
+ * components. After the ICE stream transport is created, application
+ * may initialize the STUN server settings, and after that it has to 
+ * initialize each components by calling #pj_ice_st_create_comp()
+ * function.
+ *
+ * @param stun_cfg	The STUN settings.
+ * @param name		Optional name for logging identification.
+ * @param comp_cnt	Number of components.
+ * @param user_data	Arbitrary user data to be associated with this
+ *			ICE stream transport.
+ * @param cb		Callback.
+ * @param p_ice_st	Pointer to receive the ICE stream transport
+ *			instance.
+ *
+ * @return		PJ_SUCCESS if ICE stream transport is created
+ *			successfully.
+ */
 PJ_DECL(pj_status_t) pj_ice_st_create(pj_stun_config *stun_cfg,
 				      const char *name,
 				      unsigned comp_cnt,
 				      void *user_data,
 				      const pj_ice_st_cb *cb,
 				      pj_ice_st **p_ice_st);
+
+/**
+ * Destroy the ICE stream transport. This will destroy the ICE session
+ * inside the ICE stream transport, close all sockets and release all
+ * other resources.
+ *
+ * @param ice_st	The ICE stream transport.
+ *
+ * @return		PJ_SUCCESS, or the appropriate error code.
+ */
 PJ_DECL(pj_status_t) pj_ice_st_destroy(pj_ice_st *ice_st);
 
+
+/**
+ * Set the domain to be used when resolving the STUN servers. If application
+ * wants to utillize STUN, then STUN server must be specified, either by
+ * calling this function or by calling #pj_ice_st_set_stun_srv().
+ *
+ * If application calls this function, then the STUN/TURN servers will
+ * be resolved by querying DNS SRV records for the specified domain.
+ *
+ * @param ice_st	The ICE stream transport.
+ * @param resolver	The resolver instance that will be used to
+ *			resolve the STUN/TURN servers.
+ * @param domain	The target domain.
+ *
+ * @return		PJ_SUCCESS if DNS SRV resolution job can be
+ *			started. The resolution process itself will
+ *			complete asynchronously.
+ */
 PJ_DECL(pj_status_t) pj_ice_st_set_stun_domain(pj_ice_st *ice_st,
 					       pj_dns_resolver *resolver,
 					       const pj_str_t *domain);
+
+/**
+ * Set the STUN and TURN server addresses. If application
+ * wants to utillize STUN, then STUN server must be specified, either by
+ * calling this function or by calling #pj_ice_st_set_stun_domain().
+ *
+ * With this function, the STUN and TURN server addresses will be 
+ * assigned immediately, that is no DNS resolution will need to be 
+ * performed.
+ *
+ * @param ice_st	The ICE stream transport.
+ * @param stun_srv	The STUN server address, or NULL if STUN
+ *			reflexive candidate is not to be used.
+ * @param turn_srv	The TURN server address, or NULL if STUN
+ *			relay candidate is not to be used.
+ *
+ * @return		PJ_SUCCESS, or the appropriate error code.
+ */
 PJ_DECL(pj_status_t) pj_ice_st_set_stun_srv(pj_ice_st *ice_st,
 					    const pj_sockaddr_in *stun_srv,
 					    const pj_sockaddr_in *turn_srv);
 
+/**
+ * Create and initialize the specified component. This function will
+ * instantiate the socket descriptor for this component, optionally
+ * bind the socket to the specified address (or bind to any address/port
+ * if the \a addr parameter is NULL), and start finding all alias
+ * addresses for this socket. For each alias addresses that if finds,
+ * it will add an ICE stream transport candidate for this component.
+ *
+ * After all components have been initialized, application should poll
+ * the #pj_ice_st_get_comps_status() peridically to check if STUN
+ * server reflexive and relayed candidates have been obtained
+ * successfully.
+ *
+ * @param ice_st	The ICE stream transport.
+ * @param comp_id	The component ID, which value must be greater than
+ *			zero and less than or equal to the number of 
+ *			components in this ICE stream transport.
+ * @param options	Options, see #pj_ice_st_option.
+ * @param addr		Local address where socket will be bound to. This
+ *			address will be used as follows:
+ *			- if the value is NULL, then socket will be bound
+ *			  to any available port.
+ *			- if the value is not NULL, then if the port number
+ *			  is not zero, it will used as the starting port 
+ *			  where the socket will be bound to. If bind() to
+ *			  this port fails, this function will try to bind
+ *			  to port+2, repeatedly until it succeeded.
+ *			  If application doesn't want this function to 
+ *			  retry binding the socket to other port, it can
+ *			  specify PJ_ICE_ST_OPT_NO_PORT_RETRY option.
+ *			- if the value is not NULL, then if the address
+ *			  is not INADDR_ANY, this function will bind the
+ *			  socket to this particular interface only, and
+ *			  no other host candidates will be added for this
+ *			  socket.
+ *			
+ *
+ * @return		PJ_SUCCESS, or the appropriate error code.
+ */
 PJ_DECL(pj_status_t) pj_ice_st_create_comp(pj_ice_st *ice_st,
 					   unsigned comp_id,
 					   pj_uint32_t options,
 					   const pj_sockaddr_in *addr);
+
+/**
+ * Manually add a candidate (transport address alias) for the specified
+ * component. Normally application shouldn't need to use this function,
+ * as candidates will be added automatically when component is created
+ * with #pj_ice_st_create_comp().
+ *
+ * @param ice_st	ICE stream transport.
+ * @param comp_id	The component ID.
+ * @param type		The candidate type.
+ * @param local_pref	The local preference for this candidate
+ *			(typically the value is 65535).
+ * @param addr		The candidate address.
+ * @param set_default	Set to non-zero to make this candidate the 
+ *			default candidate for this component.
+ *
+ * @return		PJ_SUCCESS, or the appropriate error code.
+ */
 PJ_DECL(pj_status_t) pj_ice_st_add_cand(pj_ice_st *ice_st,
 					unsigned comp_id,
 					pj_ice_cand_type type,
@@ -152,22 +465,105 @@ PJ_DECL(pj_status_t) pj_ice_st_add_cand(pj_ice_st *ice_st,
 					const pj_sockaddr_in *addr,
 					pj_bool_t set_default);
 
+/**
+ * Get the status of components in the ICE stream transports. Since
+ * some IP address candidates have to be obtained asynchronously (for
+ * example, the STUN reflexive or relay candidate), application can
+ * use this function to know whether the address resolution has 
+ * completed.
+ *
+ * @param ice_st	The ICE stream transport.
+ *
+ * @return		PJ_SUCCESS if all candidates have been resolved
+ *			successfully, PJ_EPENDING if transport resolution
+ *			is still in progress, or other status on failure.
+ */
 PJ_DECL(pj_status_t) pj_ice_st_get_comps_status(pj_ice_st *ice_st);
 
+/**
+ * Initialize the ICE session in the ICE stream transport.
+ *
+ * @param ice_st	The ICE stream transport.
+ * @param role		ICE role.
+ * @param local_ufrag	Optional local username fragment.
+ * @param local_passwd	Optional local password.
+ *
+ * @return		PJ_SUCCESS, or the appropriate error code.
+ */
 PJ_DECL(pj_status_t) pj_ice_st_init_ice(pj_ice_st *ice_st,
 					pj_ice_role role,
 					const pj_str_t *local_ufrag,
 					const pj_str_t *local_passwd);
+
+/**
+ * Enumerate the local candidates. This function can only be called
+ * after the ICE session has been created in the ICE stream transport.
+ *
+ * @param ice_st	The ICE stream transport.
+ * @param count		On input, it specifies the maximum number of
+ *			elements. On output, it will be filled with
+ *			the number of candidates copied to the
+ *			array.
+ * @param cand		Array of candidates.
+ *
+ * @return		PJ_SUCCESS, or the appropriate error code.
+ */
 PJ_DECL(pj_status_t) pj_ice_st_enum_cands(pj_ice_st *ice_st,
 					  unsigned *count,
 					  pj_ice_cand cand[]);
+
+/**
+ * Start ICE connectivity checks. This function can only be called
+ * after the ICE session has been created in the ICE stream transport.
+ *
+ * This function will pair the local and remote candidates to create 
+ * check list. Once the check list is created and sorted based on the
+ * priority, ICE periodic checks will be started. This function will 
+ * return immediately, and application will be notified about the 
+ * connectivity check status in the callback.
+ *
+ * @param ice_st	The ICE stream transport.
+ * @param rem_ufrag	Remote ufrag, as seen in the SDP received from 
+ *			the remote agent.
+ * @param rem_passwd	Remote password, as seen in the SDP received from
+ *			the remote agent.
+ * @param rem_cand_cnt	Number of remote candidates.
+ * @param rem_cand	Remote candidate array.
+ *
+ * @return		PJ_SUCCESS, or the appropriate error code.
+ */
 PJ_DECL(pj_status_t) pj_ice_st_start_ice(pj_ice_st *ice_st,
 					 const pj_str_t *rem_ufrag,
 					 const pj_str_t *rem_passwd,
 					 unsigned rem_cand_cnt,
 					 const pj_ice_cand rem_cand[]);
+
+/**
+ * Stop and destroy the ICE session inside this media transport.
+ *
+ * @param ice_st	The ICE stream transport.
+ *
+ * @return		PJ_SUCCESS, or the appropriate error code.
+ */
 PJ_DECL(pj_status_t) pj_ice_st_stop_ice(pj_ice_st *ice_st);
 
+
+/**
+ * Send outgoing packet using this transport. If ICE checks have not 
+ * produced a valid check for the specified component ID, this function 
+ * will return with failure. Otherwise it will send the packet to remote
+ * destination using the nominated local candidate as have been checked
+ * previously.
+ *
+ * @param ice_st	The ICE stream transport.
+ * @param comp_id	Component ID.
+ * @param data		The data or packet to be sent.
+ * @param data_len	Size of data or packet, in bytes.
+ * @param dst_addr	The destination address.
+ * @param dst_addr_len	Length of destination address.
+ *
+ * @return		PJ_SUCCESS if data is sent successfully.
+ */
 PJ_DECL(pj_status_t) pj_ice_st_sendto(pj_ice_st *ice_st,
 				      unsigned comp_id,
 				      const void *data,
diff --git a/pjnath/include/pjnath/stun_auth.h b/pjnath/include/pjnath/stun_auth.h
index 1a9f6a0c..6914036d 100644
--- a/pjnath/include/pjnath/stun_auth.h
+++ b/pjnath/include/pjnath/stun_auth.h
@@ -33,6 +33,7 @@ PJ_BEGIN_DECL
 /* **************************************************************************/
 /**
  * @defgroup PJNATH_STUN_AUTH STUN Authentication
+ * @brief STUN authentication helper
  * @ingroup PJNATH_STUN
  * @{
  */
@@ -298,8 +299,15 @@ PJ_DECL(pj_status_t) pj_stun_verify_credential(const pj_uint8_t *pkt,
  */
 
 
-/* Calculate HMAC-SHA1 key for long term credential, by getting
+/**
+ * Calculate HMAC-SHA1 key for long term credential, by getting
  * MD5 digest of username, realm, and password. 
+ *
+ * @param digest    The buffer for the digest.
+ * @param realm	    The realm of the credential, if long term credential
+ *		    is to be used.
+ * @param username  The username.
+ * @param passwd    The clear text password.
  */
 void pj_stun_calc_md5_key(pj_uint8_t digest[16],
 			  const pj_str_t *realm,
diff --git a/pjnath/include/pjnath/stun_doc.h b/pjnath/include/pjnath/stun_doc.h
deleted file mode 100644
index 7b5e6511..00000000
--- a/pjnath/include/pjnath/stun_doc.h
+++ /dev/null
@@ -1,100 +0,0 @@
-/* $Id$ */
-/* 
- * Copyright (C) 2003-2005 Benny Prijono <benny@prijono.org>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA 
- */
-#ifndef __PJ_STUN_SERVER_H__
-#define __PJ_STUN_SERVER_H__
-
-/*
- * STUN documentation. There is no code here.
- */
-
-/**
- * @defgroup PJNATH_STUN STUN and TURN
- * @ingroup PJNATH
-
- This is the implementation of STUN/TURN in PJLIB-UTIL library.
-
- The STUN/TURN implementation in PJLIB-UTIL has the following objectives:
- - standard based (of course)
- - supports both client and server side STUN/TURN services
- - independent (that is, only dependent to pjlib), and general purpose
-   enough to be used not only by pjsip applications but also by other 
-   types of applications
- - must be able to support ICE.
-
- The STUN/TURN implementation is based on the following standards:
- - <A HREF="http://www.ietf.org/internet-drafts/draft-ietf-behave-rfc3489bis-05.txt">
-   draft-ietf-behave-rfc3489bis-05.txt</A>
- - <A HREF="http://www.ietf.org/internet-drafts/draft-ietf-behave-turn-02.txt">
-   draft-ietf-behave-turn-02.txt</A>
-
- But as STUN standards are currently defined as work in progress at IETF,
- the implementation will be updated as these standards are updated.
-
-  
-
- @section stun_org_sec Organization
-
- The implementation consists of the following components.
-
- @subsection stun_msg_sec Messaging and Parsing
-
- The lowest layer of the STUN implementation is the @ref PJNATH_STUN_MSG
- component. This part is responsible for encoding and decoding STUN messages.
-
- This layer only implements message representation and parsing. In particular,
- it does not provide any transport functionalities, therefore it can be used
- by different types of applications.
-
-
-
- @subsection stun_endpt_sec Endpoint
-
- The @ref PJNATH_STUN_ENDPOINT is used by the library to put together
- common settings for all STUN objects. For example, the STUN endpoint has a
- reference of timer heap to poll all STUN timers, reference to ioqueue to
- poll network events for STUN servers, and some common settings used by
- various STUN objects.
-
-
- @subsection stun_clt_tsx_sec Client Transaction
-
- The @ref PJNATH_STUN_TRANSACTION is used to manage outgoing STUN request,
- for example to retransmit the request and to notify application about the
- completion of the request.
-
- The @ref PJNATH_STUN_TRANSACTION does not use any networking operations,
- but instead application must supply the transaction with a callback to
- be used by the transaction to send outgoing requests. This way the STUN
- transaction is made more generic and can work with different types of
- networking codes in application.
-
-
-
- @subsection stun_srv_sec Server Components
-
- The @ref PJNATH_STUN_SERVER is used for:
- - implementing STUN servers, and/or
- - implementing server side STUN handling (for example for ICE).
-
- */
-
-
-
-#endif	/* __PJ_STUN_SERVER_H__ */
-
diff --git a/pjnath/include/pjnath/stun_msg.h b/pjnath/include/pjnath/stun_msg.h
index 3362703c..a63fb7a0 100644
--- a/pjnath/include/pjnath/stun_msg.h
+++ b/pjnath/include/pjnath/stun_msg.h
@@ -41,54 +41,6 @@ PJ_BEGIN_DECL
 
 
 /**
- * The default initial STUN round-trip time estimation (the RTO value
- * in RFC 3489-bis), in miliseconds. 
- * This value is used to control the STUN request 
- * retransmit time. The initial value of retransmission interval 
- * would be set to this value, and will be doubled after each
- * retransmission.
- */
-#ifndef PJ_STUN_RTO_VALUE
-#   define PJ_STUN_RTO_VALUE		    100
-#endif
-
-
-/**
- * The STUN transaction timeout value, in miliseconds.
- * After the last retransmission is sent and if no response is received 
- * after this time, the STUN transaction will be considered to have failed.
- *
- * The default value is 1600 miliseconds (as per RFC 3489-bis).
- */
-#ifndef PJ_STUN_TIMEOUT_VALUE
-#   define PJ_STUN_TIMEOUT_VALUE	    1600
-#endif
-
-
-/**
- * Maximum number of STUN retransmission count.
- *
- * Default: 7 (as per RFC 3489-bis)
- */
-#ifndef PJ_STUN_MAX_RETRANSMIT_COUNT
-#   define PJ_STUN_MAX_RETRANSMIT_COUNT	    7
-#endif
-
-
-/**
- * Maximum size of STUN message.
- */
-#ifndef PJ_STUN_MAX_PKT_LEN
-#   define PJ_STUN_MAX_PKT_LEN		    512
-#endif
-
-
-/**
- * Default STUN port as defined by RFC 3489.
- */
-#define PJ_STUN_PORT			    3478
-
-/**
  * STUN magic cookie.
  */
 #define PJ_STUN_MAGIC			    0x2112A442
diff --git a/pjnath/include/pjnath/stun_session.h b/pjnath/include/pjnath/stun_session.h
index 18d07c0f..9f5a0d60 100644
--- a/pjnath/include/pjnath/stun_session.h
+++ b/pjnath/include/pjnath/stun_session.h
@@ -19,6 +19,11 @@
 #ifndef __PJNATH_STUN_SESSION_H__
 #define __PJNATH_STUN_SESSION_H__
 
+/**
+ * @file stun_session.h
+ * @brief STUN session management for client/server.
+ */
+
 #include <pjnath/stun_msg.h>
 #include <pjnath/stun_auth.h>
 #include <pjnath/stun_config.h>
@@ -187,6 +192,7 @@ PJ_DECL(pj_status_t) pj_stun_session_destroy(pj_stun_session *sess);
  * be retrieved later with pj_stun_session_get_user_data() function.
  *
  * @param sess	    The STUN session instance.
+ * @param user_data The user data.
  *
  * @return	    PJ_SUCCESS on success, or the appropriate error code.
  */
@@ -351,15 +357,17 @@ PJ_DECL(pj_status_t) pj_stun_session_cancel_req(pj_stun_session *sess,
  * On successful message processing, application will be notified about
  * the message via one of the pj_stun_session_cb callback.
  *
- * @param sess	     The STUN session instance.
- * @param packet     The packet containing STUN message.
- * @param pkt_size   Size of the packet.
- * @param options    Options, from #pj_stun_decode_options.
- * @param parsed_len Optional pointer to receive the size of the parsed
- *		     STUN message (useful if packet is received via a
- *		     stream oriented protocol).
- *
- * @return	     PJ_SUCCESS on success, or the appropriate error code.
+ * @param sess		The STUN session instance.
+ * @param packet	The packet containing STUN message.
+ * @param pkt_size	Size of the packet.
+ * @param options	Options, from #pj_stun_decode_options.
+ * @param parsed_len	Optional pointer to receive the size of the parsed
+ *			STUN message (useful if packet is received via a
+ *			stream oriented protocol).
+ * @param src_addr	The source address of the packet.
+ * @param src_addr_len	Length of the source address.
+ *
+ * @return		PJ_SUCCESS on success, or the appropriate error code.
  */
 PJ_DECL(pj_status_t) pj_stun_session_on_rx_pkt(pj_stun_session *sess,
 					       const void *packet,
diff --git a/pjnath/include/pjnath/stun_transaction.h b/pjnath/include/pjnath/stun_transaction.h
index 02b0af9e..f296c9f5 100644
--- a/pjnath/include/pjnath/stun_transaction.h
+++ b/pjnath/include/pjnath/stun_transaction.h
@@ -191,13 +191,7 @@ PJ_DECL(pj_status_t) pj_stun_client_tsx_send_msg(pj_stun_client_tsx *tsx,
  * with a final response later to allow the transaction to complete.
  *
  * @param tsx		The STUN client transaction instance.
- * @param packet	The incoming packet.
- * @param pkt_size	Size of the incoming packet.
- * @param parsed_len	Optional pointer to receive the number of bytes
- *			that have been parsed from the incoming packet
- *			for the STUN message. This is useful if the
- *			STUN transaction is running over stream oriented
- *			socket such as TCP or TLS.
+ * @param msg		The incoming STUN message.
  *
  * @return		PJ_SUCCESS on success or the appropriate error code.
  */
diff --git a/pjnath/include/pjnath/turn_client.h b/pjnath/include/pjnath/turn_client.h
deleted file mode 100644
index b9cfacc0..00000000
--- a/pjnath/include/pjnath/turn_client.h
+++ /dev/null
@@ -1,132 +0,0 @@
-/* $Id$ */
-/* 
- * Copyright (C) 2003-2005 Benny Prijono <benny@prijono.org>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA 
- */
-#ifndef __PJNATH_TURN_CLIENT_H__
-#define __PJNATH_TURN_CLIENT_H__
-
-/**
- * @file turn_client.h
- * @brief TURN client session.
- */
-
-#include <pjnath/stun_msg.h>
-
-
-PJ_BEGIN_DECL
-
-
-/**
- * @defgroup PJNATH_TURN_CLIENT TURN Client Session
- * @brief Management of STUN/TURN client session
- * @ingroup PJNATH_STUN
- * @{
- */
-
-typedef struct pj_turn_client pj_turn_client;
-
-/**
- * This describes TURN client config.
- */
-typedef struct pj_turn_client_cb
-{
-    /**
-     * Callback to be called by the TURN session to send outgoing message.
-     *
-     * @param client	    The TURN client session.
-     * @param pkt	    Packet to be sent.
-     * @param pkt_size	    Size of the packet to be sent.
-     * @param dst_addr	    The destination address.
-     * @param addr_len	    Length of destination address.
-     *
-     * @return		    The callback should return the status of the
-     *			    packet sending.
-     */
-    pj_status_t (*on_send_msg)(pj_turn_client *client,
-			       const void *pkt,
-			       pj_size_t pkt_size,
-			       const pj_sockaddr_t *dst_addr,
-			       unsigned addr_len);
-
-    /**
-     * Callback to be called by TURN session when its state has changed.
-     */
-    pj_status_t (*on_state_changed)(pj_turn_client *client);
-
-} pj_turn_client_cb;
-
-
-/**
- * Options
- */
-typedef struct pj_turn_client_config
-{
-    int	    bandwidth;
-    int	    lifetime;
-    int	    sock_type;
-    int	    port;
-} pj_turn_client_config;
-
-
-PJ_INLINE(void) pj_turn_client_config_default(pj_turn_client_config *cfg)
-{
-    pj_bzero(cfg, sizeof(*cfg));
-    cfg->bandwidth = -1;
-    cfg->lifetime = -1;
-    cfg->sock_type = -1;
-    cfg->port = -1;
-}
-
-
-/**
- * This describes the TURN client session.
- */
-struct pj_turn_client
-{
-    pj_pool_t	    *pool;
-    pj_stun_session *session;
-    pj_timer_entry   alloc_timer;
-    pj_sockaddr_in   mapped_addr;
-    pj_sockaddr_in   relay_addr;
-};
-
-
-
-
-/**
- * Create the TURN client session.
- */
-PJ_DECL(pj_status_t) pj_turn_client_create(pj_stun_endpoint *endpt,
-					   const pj_turn_client_config *cfg,
-					   const pj_turn_client_cb *cb,
-					   pj_turn_client **p_client);
-
-/**
- * Start the TURN client session by sending Allocate request to the server.
- */
-
-
-/**
- * @}
- */
-
-
-PJ_END_DECL
-
-
-#endif	/* __PJNATH_TURN_CLIENT_H__ */
-
diff --git a/pjnath/include/pjnath/types.h b/pjnath/include/pjnath/types.h
index 0d9dc61c..bc47c9a2 100644
--- a/pjnath/include/pjnath/types.h
+++ b/pjnath/include/pjnath/types.h
@@ -28,7 +28,7 @@
 #include <pjnath/config.h>
 
 /**
- * @defgroup PJNATH NAT Helper Library
+ * @defgroup PJNATH NAT Traversal Helper Library
  * @{
  */
 
@@ -51,17 +51,156 @@ PJ_END_DECL
 /* Doxygen documentation below: */
 
 /**
- * @mainpage NAT Helper Library
+ * @mainpage PJNATH - Open Source STUN, TURN, and ICE Library
  *
  * \n
+ * This is the documentation of PJNATH, an Open Source library providing
+ * NAT traversal helper functionalities by using standard based protocols 
+ * such as:
+ *  - <b>STUN</b> (Session Traversal Utilities),
+ *  - <b>TURN</b> (Obtaining Relay Addresses from STUN)
+ *  - <b>ICE</b> (Interactive Connectivity Establishment).
+ * 
+ * The following sections will give a short overview about the protocols
+ * supported by this library, and how they are implemented in PJNATH.
+ *
  * \n
+
+ * \section PJNATH_STUN STUN Protocol Library
+ *
+ * Session Traversal Utilities (STUN, or previously known as Simple 
+ * Traversal of User Datagram Protocol (UDP) Through Network Address 
+ * Translators (NAT)s), was previously released as IETF standard
+ * <A HREF="http://www.ietf.org/rfc/rfc3489.txt">RFC 3489</A>, but since
+ * then it has been revised into the following:
+ *  - <A HREF="http://www.ietf.org/internet-drafts/draft-ietf-behave-rfc3489bis-06.txt">
+ *    <B>draft-ietf-behave-rfc3489bis-06</b></A> for the main STUN 
+ *    specification,
+ *  - <A HREF="http://www.ietf.org/internet-drafts/draft-ietf-behave-turn-03.txt">
+ *    <B>draft-ietf-behave-turn-03</B></A> for TURN usage of STUN,
+ *  - and several other drafts explaining other STUN usages.
+ * 
+ * The PJNATH library provides facilities to support both the core 
+ * <B>STUN-bis</B> specification and the <B>TURN</B> usage of STUN, 
+ * as well as other STUN usages. Please see #pj_stun_attr_type for 
+ * list of STUN attributes supported by this library.
+ *
+ * 
+ * The following are some design principles that have been utilized
+ * when implementing the STUN library in PJNATH:
+ *
+ *  - layered architecture, with \ref PJNATH_STUN_MSG as the lowest
+ *    layer and \ref PJNATH_STUN_SESSION as the highest abstraction
+ *    layer, to accommodate various usage scenario of the library.
+ *
+ *  - no transport -- the STUN library is pretty much transport
+ *    independent and all sending and receiving functionalities will
+ *    have to be implemented by application or higher level
+ *    abstraction (such as ICE). This helps facilitating an even
+ *    more usage scenarios of the library.
+ *
+ *  - common functionalities for both STUN client and server
+ *    development. All STUN components can be used to develop both
+ *    STUN client and STUN server application, and in fact, in ICE,
+ *    both STUN client and server functionality exist in a single
+ *    ICE session.
+ *
  * \n
- * This is the documentation of PJNATH, an auxiliary library providing
- * NAT helper functionalities such as STUN and ICE.
+ *
+ * \subsection PJNATH_STUN_ARCH STUN Library Organization
+ *
+
+ \verbatim
+
+    +-----------------------------------------------------------------+
+    |                                                                 |
+    |                   A P P L I C A T I O N                         |
+    |                                                                 |
+    +-----------------------------------------------------------------+
+         ^                          ^
+         |                          |
+         v                          v
+    +--------+    +-----------------------------------+    +----------+
+    |        |    |                                   |    |          |
+    |  Appl- |<-->|      S T U N   S E S S I O N      |<-->| S T U N  |
+    | ication|    |                                   |    |  Authen- |
+    | Trans- |    +-----------------------------------+    | tication |
+    |  port  |    |                                   |    |          |
+    |        |<-->|  S T U N   T R A N S A C T I O N  |    +----------+
+    |        |    |                                   |
+    |        |    +-----------------------------------+
+    |        |    |                                   |
+    |        |    |    STUN MESSAGE REPRESENTATION    |
+    +--------+    |            AND PARSING            |
+                  +-----------------------------------+
+
+ \endverbatim
+
+ * The STUN library is organized as follows:
+ *
+ *  - the lowest layer of the library is \ref PJNATH_STUN_MSG. This layer
+ *    provides STUN message representation, validation, parsing, and
+ *    debugging (dump to log) of STUN messages.
+ *
+ *  - for client, the next higher layer is \ref PJNATH_STUN_TRANSACTION,
+ *    which manages retransmissions of STUN request.
+ *
+ *  - \ref PJNATH_STUN_AUTH provides mechanism to verify STUN
+ *    credential in incoming STUN messages.
+ *
+ *  - for both client and server, the next higher abstraction is
+ *    \ref PJNATH_STUN_SESSION, which provides management of incoming
+ *    and outgoing messages and association of STUN credential to
+ *    a STUN session.
+ *
+ * As mentioned previously, all STUN library components are independent
+ * of any transports. Application gives incoming packet
+ * to the STUN components for processing. and it must supply the STUN 
+ * components with callback to send outgoing messages.
+ * 
+ * \n
+ *
+ * \section PJNATH_ICE ICE Implementation
+ *
+ * Interactive Connectivity Establishment (ICE) is a standard based 
+ * methodology for traversing Network Address Translator (NAT), and
+ * is described in 
+ * <A HREF="http://www.ietf.org/internet-drafts/draft-ietf-mmusic-ice-14.txt">
+ * <B>draft-ietf-mmusic-ice-14.txt</B></A> draft. The PJNATH ICE
+ * implementation is aimed to provide a usable and generic ICE transports
+ * for different types of application, including but not limited to
+ * the usage of ICE in SIP/SDP offer/answer.
+ * 
+ * \subsection PJNATH_ICE_ARCH ICE Library Organization
  * 
- * Please go to the <A HREF="modules.htm"><B>Modules</B></A> page for list
- * of modules.
+ * The ICE library is organized as follows:
+ *
+ *  - the lowest layer is \ref PJNATH_ICE_SESSION, which provides 
+ *    ICE management and negotiation in a transport-independent way.
+ *    This layer contains the state machines to perform ICE
+ *    negotiation, and provides the most flexibility to control all
+ *    aspects of ICE session. This layer normally is only usable for
+ *    ICE implementors.
+ *
+ *  - higher in the hierarchy is \ref PJNATH_ICE_STREAM_TRANSPORT,
+ *    which binds ICE with UDP sockets, and provides STUN binding
+ *    and relay/TURN allocation for the sockets. This component can
+ *    be directly used by application, although normally application
+ *    should use the next higher abstraction below since it provides
+ *    SDP translations and better integration with other PJ libraries
+ *    such as PJSIP and PJMEDIA.
+ *
+ *  - the highest abstraction is ICE media transport, which maintains
+ *    ICE stream transport and provides SDP translations to be used
+ *    for SIP offer/answer exchanges.
+ */
+
+/**
+ * @defgroup PJNATH_STUN STUN Library
+ * @brief Open source STUN library
  *
+ * This module contains implementation of STUN library in PJNATH -
+ * the open source NAT helper containing STUN and ICE.
  */
 
 #endif	/* __PJNATH_TYPES_H__ */