[sorry about previous mis-post] I have an * switch at home and one in the office. Both similar new CVS head versions and both with chan_sip2 built in: Asterisk CVS-HEAD-10/12/04-17:43:26 Asterisk CVS-HEAD-10/13/04-12:53:52 One is on a T1 connection and the other is on 576k/288k ADSL. The Ping time is about 30ms between the two servers, 90% of which is the ADSL delay. When I interconnect them with IAX2, I get rather choppy audio - with what sounds like dropped packets and jitter. However when I interconnect with SIP is it clean and with no dropouts. The network path and timings are identical for both protocols and there is little noticeable difference when I play with the jitterbuffer setting in iax.conf. Does anyone have any idea why IAX protocol is causing this kind of problem? My ADSL is PPPoE which has an MTU of 1492 I think. Could this be causing the problems? Peter This e-mail and any attachment is for authorised use by the intended recipient(s) only. It may contain proprietary material, confidential information and/or be subject to legal privilege. It should not be copied, disclosed to, retained or used by, any other party. If you are not an intended recipient then please promptly delete this e-mail and any attachment and all copies and inform the sender. Thank you.
Whisker, Peter wrote:>[sorry about previous mis-post] > >I have an * switch at home and one in the office. Both similar new CVS head >versions and both with chan_sip2 built in: > >Asterisk CVS-HEAD-10/12/04-17:43:26 >Asterisk CVS-HEAD-10/13/04-12:53:52 > >One is on a T1 connection and the other is on 576k/288k ADSL. The Ping time >is about 30ms between the two servers, 90% of which is the ADSL delay. > >When I interconnect them with IAX2, I get rather choppy audio - with what >sounds like dropped packets and jitter. > >However when I interconnect with SIP is it clean and with no dropouts. The >network path and timings are identical for both protocols and there is >little noticeable difference when I play with the jitterbuffer setting in >iax.conf. > >Does anyone have any idea why IAX protocol is causing this kind of problem? >My ADSL is PPPoE which has an MTU of 1492 I think. Could this be causing the >problems? > >No, you shouldn't be sending any IAX2 packets which approach this size. 1) What codecs are you using in each case? 2) Do you have other traffic on the link? It's possible that somewhere along your path, the RTP audio traffic from SIP is getting some kind of helpful QoS benefit, while the IAX2 traffic is not? -SteveK
>One is on a T1 connection and the other is on 576k/288k ADSL. The Ping time >is about 30ms between the two servers, 90% of which is the ADSL delay. > >When I interconnect them with IAX2, I get rather choppy audio - with what >sounds like dropped packets and jitter. > >However when I interconnect with SIP is it clean and with no dropouts. The >network path and timings are identical for both protocols and there is >little noticeable difference when I play with the jitterbuffer setting in >iax.conf. > >Does anyone have any idea why IAX protocol is causing this kind of problem? >My ADSL is PPPoE which has an MTU of 1492 I think. Could this be causingthe>problems? > >No, you shouldn't be sending any IAX2 packets which approach this size. 1) What codecs are you using in each case? 2) Do you have other traffic on the link? It's possible that somewhere along your path, the RTP audio traffic from SIP is getting some kind of helpful QoS benefit, while the IAX2 traffic is not? ============ No. I test when the link is quiet. I have tried Ulaw and GSM - in fact bizarrely the GSM is worse. The processors on the Asterisk boxes are only 5% loaded - they are 500MHz Pentiums so this should not be the problem. I don't know about the QoS but have never noticed any difference in the various settings. Peter This e-mail and any attachment is for authorised use by the intended recipient(s) only. It may contain proprietary material, confidential information and/or be subject to legal privilege. It should not be copied, disclosed to, retained or used by, any other party. If you are not an intended recipient then please promptly delete this e-mail and any attachment and all copies and inform the sender. Thank you.