func_channel: Reorganize documentation

* Following the example of the PJSIP channel driver, the channel
  technology specific documentation has been moved to the respective
  channel drivers that provide that functionality. This has the benefit
  of locating the documentation of items with those modules that provide
  it.

* Examples of using the CHANNEL function for both standard items as well
  as for PJSIP have been added.

* The 'max_forwards' standard item has been documented.

Change-Id: Ifaa79a232c8ac99cf8da6ef6cc7815d398b1b79b

1 files changed, 82 insertions, 0 deletions

diff --git a/channels/sip/dialplan_functions.c b/channels/sip/dialplan_functions.c
index 644da3852..988378835 100644
--- a/channels/sip/dialplan_functions.c
+++ b/channels/sip/dialplan_functions.c
@@ -23,6 +23,88 @@
 	<support_level>extended</support_level>
  ***/
 
+/*** DOCUMENTATION
+<info name="SIPCHANNEL" language="en_US" tech="SIP">
+	<enumlist>
+		<enum name="peerip">
+			<para>R/O Get the IP address of the peer.</para>
+		</enum>
+		<enum name="recvip">
+			<para>R/O Get the source IP address of the peer.</para>
+		</enum>
+		<enum name="recvport">
+			<para>R/O Get the source port of the peer.</para>
+		</enum>
+		<enum name="from">
+			<para>R/O Get the URI from the From: header.</para>
+		</enum>
+		<enum name="uri">
+			<para>R/O Get the URI from the Contact: header.</para>
+		</enum>
+		<enum name="useragent">
+			<para>R/O Get the useragent.</para>
+		</enum>
+		<enum name="peername">
+			<para>R/O Get the name of the peer.</para>
+		</enum>
+		<enum name="t38passthrough">
+			<para>R/O <literal>1</literal> if T38 is offered or enabled in this channel,
+			otherwise <literal>0</literal></para>
+		</enum>
+		<enum name="rtpqos">
+			<para>R/O Get QOS information about the RTP stream</para>
+			<para>    This option takes two additional arguments:</para>
+			<para>    Argument 1:</para>
+			<para>     <literal>audio</literal>             Get data about the audio stream</para>
+			<para>     <literal>video</literal>             Get data about the video stream</para>
+			<para>     <literal>text</literal>              Get data about the text stream</para>
+			<para>    Argument 2:</para>
+			<para>     <literal>local_ssrc</literal>        Local SSRC (stream ID)</para>
+			<para>     <literal>local_lostpackets</literal> Local lost packets</para>
+			<para>     <literal>local_jitter</literal>      Local calculated jitter</para>
+			<para>     <literal>local_maxjitter</literal>   Local calculated jitter (maximum)</para>
+			<para>     <literal>local_minjitter</literal>   Local calculated jitter (minimum)</para>
+			<para>     <literal>local_normdevjitter</literal>Local calculated jitter (normal deviation)</para>
+			<para>     <literal>local_stdevjitter</literal> Local calculated jitter (standard deviation)</para>
+			<para>     <literal>local_count</literal>       Number of received packets</para>
+			<para>     <literal>remote_ssrc</literal>       Remote SSRC (stream ID)</para>
+			<para>     <literal>remote_lostpackets</literal>Remote lost packets</para>
+			<para>     <literal>remote_jitter</literal>     Remote reported jitter</para>
+			<para>     <literal>remote_maxjitter</literal>  Remote calculated jitter (maximum)</para>
+			<para>     <literal>remote_minjitter</literal>  Remote calculated jitter (minimum)</para>
+			<para>     <literal>remote_normdevjitter</literal>Remote calculated jitter (normal deviation)</para>
+			<para>     <literal>remote_stdevjitter</literal>Remote calculated jitter (standard deviation)</para>
+			<para>     <literal>remote_count</literal>      Number of transmitted packets</para>
+			<para>     <literal>rtt</literal>               Round trip time</para>
+			<para>     <literal>maxrtt</literal>            Round trip time (maximum)</para>
+			<para>     <literal>minrtt</literal>            Round trip time (minimum)</para>
+			<para>     <literal>normdevrtt</literal>        Round trip time (normal deviation)</para>
+			<para>     <literal>stdevrtt</literal>          Round trip time (standard deviation)</para>
+			<para>     <literal>all</literal>               All statistics (in a form suited to logging,
+			but not for parsing)</para>
+		</enum>
+		<enum name="rtpdest">
+			<para>R/O Get remote RTP destination information.</para>
+			<para>   This option takes one additional argument:</para>
+			<para>    Argument 1:</para>
+			<para>     <literal>audio</literal>             Get audio destination</para>
+			<para>     <literal>video</literal>             Get video destination</para>
+			<para>     <literal>text</literal>              Get text destination</para>
+			<para>   Defaults to <literal>audio</literal> if unspecified.</para>
+		</enum>
+		<enum name="rtpsource">
+			<para>R/O Get source RTP destination information.</para>
+			<para>   This option takes one additional argument:</para>
+			<para>    Argument 1:</para>
+			<para>     <literal>audio</literal>             Get audio destination</para>
+			<para>     <literal>video</literal>             Get video destination</para>
+			<para>     <literal>text</literal>              Get text destination</para>
+			<para>   Defaults to <literal>audio</literal> if unspecified.</para>
+		</enum>
+	</enumlist>
+</info>
+ ***/
+
 #include "asterisk.h"
 
 ASTERISK_REGISTER_FILE()