Hi, the simplest method to reduce network usage is put more than 1 compressed sound frame into each udp packet.
This does increase the latency, but it is not noticable. There is already a 200 msec transmit time, 200ms jitter buffer. An extra 40ms cause there are an extra is 2 gsm frames in an audio packet will not be significant. The chart at: http://www.voxgratia.org/docs/codecbw.html illustrates this point. I am told that IAX2 does have the option of allowing you to put more audio frames into each packet. I know that H.323 and SIP have been doing this for years also. Derek. =============================================================== On Sun, 12 Feb 2006, Kristian Kielhofner wrote: > Hello everyone, > > A long, long time ago someone somewhere told me about a feature with > RTP to reduce overhead (and bandwidth). By trunking I mean trunking as > in "IAX trunking" - stuffing multiple voice channels into the same UDP > packet on connections between the same systems to reduce UDP/etc > overhead (you know what I am talking about). :) > > I was told that such a feature exists for use with RTP. The closest > thing that I have been able to find is RTP header compression (RFC > 2508). With the calculations that I have seen, RTP header compression > can increase call capacity by over %50: > > http://www.connect802.com/voip_bandwidth.php > > Are there any other ways to improve bandwidth usage with SIP/RTP? > Perhaps something more like IAX trunking? RFC 2508 appears to only > apply to PtP serial links (it also compresses the IP header, but that > may be optional). I'll continue to read the spec. > > Lets just say that RFC 2508 (or something like it) is the only way to > reduce RTP bandwidth usage. I have several questions: > > If an ideal implementation for Asterisk was created, would it stand a > chance of being put in CVS? What equipment/vendors also support it? > This is key. If I'm using just Asterisk (I wish) I would just use IAX2! > > Thanks! > > -- Derek Smithies Ph.D. Any fool can write code that IndraNet Technologies Ltd. a computer can understand. Email: [EMAIL PROTECTED] Good programmers write code ph +64 3 365 6485 that humans can understand. Web: http://www.indranet-technologies.com/ Martin Fowler _______________________________________________ --Bandwidth and Colocation provided by Easynews.com -- asterisk-dev mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-dev
