Merged revisions 223756 via svnmerge from

https://origsvn.digium.com/svn/asterisk/trunk

........
  r223756 | dvossel | 2009-10-12 15:58:27 -0500 (Mon, 12 Oct 2009) | 5 lines

  Clarifies trunkmaxsize, trunkfreq, and trunkmtu iax2 options

  SWP-151
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git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/1.6.0@223759 65c4cc65-6c06-0410-ace0-fbb531ad65f3

diff --git a/configs/iax.conf.sample b/configs/iax.conf.sample
index 13ed6d62960900e5b457ecac7be49dcb0807af87..ac20d004dfc5e7408cea18505cc7317932095794 100644 (file)
--- a/configs/iax.conf.sample
+++ b/configs/iax.conf.sample
@@ -148,7 +148,42 @@ forcejitterbuffer=no
 ;resyncthreshold=1000
 ;jittertargetextra=40
 
-;trunkfreq=20                  ; How frequently to send trunk msgs (in ms)
+; Minimum and maximum amounts of time that IAX peers can request as
+; a registration expiration interval (in seconds).
+; minregexpire = 60
+; maxregexpire = 60
+;
+
+; This option defines the maximum payload in bytes an IAX2 trunk can support at a given time.
+; The best way to explain this is to provide an example.  If the maximum number of calls
+; to be supported is 200, and each call transmits 40ms frames of audio using uncompressed
+; 16bit signed linear ((8000hz / 1000ms) * 2 bytes = 640 bytes per frame), the maximum load
+; in bytes is (640 bytes per frame) * (200 calls) = 128000 bytes total. Once this limit is
+; reached, calls may be dropped or begin to loose audio.  Depending on the codec in use and
+; number of channels to be supported this value may need to be raised, but in most cases the
+; default value is large enough.
+;
+; trunkmaxsize = 128000 ; defaults to 128000 bytes, which supports up to 200 calls of 16 bit
+;                       ; signed linear audio at 40ms a frame.
+
+; With a large amount of traffic on IAX2 trunks, there is a risk of bad voice quality when
+; allowing the Linux system to handle fragmentation of UDP packets. Depending on the size of
+; each payload, allowing the O/S to handle fragmentation may not be very efficient. This
+; setting sets the maximum transmission unit for IAX2 UDP trunking. The default is 1240 bytes
+; which means if a trunk's payload is over 1240 bytes for every 20ms it will be broken into
+; multiple 1240 byte messages.  Zero disables this functionality and let's the O/S handle
+; fragmentation.
+;
+; trunkmtu = 1240 ; trunk data will be sent in 1240 byte messages.
+
+; trunkfreq sets how frequently trunk messages are sent in milliseconds. This value is 20ms by
+; default, which means the trunk will send all the date queued to it in the past 20ms.  By
+; increasing the time between sending trunk messages, the trunk's payload size will increase as
+; well.  Note, depending on the size set by trunkmtu, messages may be sent more often than
+; specified.  For example if a trunk's message size grows to the trunkmtu size before 20ms is
+; reached that message will be sent immediately.
+;
+; trunkfreq=20     ; How frequently to send trunk msgs (in ms). This is 20ms by default.
 
 ; Should we send timestamps for the individual sub-frames within trunk frames?
 ; There is a small bandwidth use for these (less than 1kbps/call), but they
@@ -159,24 +194,6 @@ forcejitterbuffer=no
 ;
 ; trunktimestamps=yes
 ;
-; Minimum and maximum amounts of time that IAX peers can request as
-; a registration expiration interval (in seconds).
-; minregexpire = 60
-; maxregexpire = 60
-;
-; With a large amount of traffic on IAX2 trunks, there is a risk of bad voice quality due to
-; the fact that the IAX2 trunking scheme depends on the Linux system to handle fragmentation of
-; UDP packets. This may not be very efficient. 
-; This setting sets the maximum transmission unit for IAX2 UDP trunking.
-; default is 1240 bytes. Zero disables this functionality and let's the O/S handle fragmentation.
-;
-; trunkmtu = 0
-;
-
-; This option defines the maximum size an IAX2 trunk can grow to. The default value is 128000 bytes which
-; represents 40ms uncompressed linear with 200 channels. Depending on different things though
-; (codec in use and channels) you may need to make this value larger.
-; trunkmaxsize = 128000
 
 ; IAX helper threads