[Asterisk-Users] IAX2 update - timestamp issue within iax pkts
For those that might be using Cisco 7940/7960 sip phones and placing calls across an iax2 link, we think the voice quality problem has been identified and corrected. The dev cvs should be updated as of about 3:30pm CDT today (April 14). History: Calls originating from a Cisco 79x0 sip phone and sent via iax2 link to some distant * machine resulted in very poor quality audio, and in some cases, the audio was so choppy as to be unusable. The quality problem surfaced around March 5th when coding changes were made to directly associate iax2 timestamps with the sip/rtp timestamps sent to the sip phones. The actual problem was traced back to timestamp issues within the iax2 packets being transmitted from the distant end. Those timestamps were suppose to be exactly 20 milliseconds from one iax2 packet to another, however in actual practice they ranged from as low as 10 milliseconds to well over 40 milliseconds (as observed with ethereal). When those seemingly random iax2 timestamps were transcoded to sip/rtp timestamps, the rtp timestamps became seemingly random. The Cisco 7940/60 phones running v6.x code effectively dumped any rtp packet that did not occur on nice 160 millisecond boundaries. In other words, if the timestamp sent to the Cisco was 152 milliseconds, inbound audio on the Cisco stopped. Very disruptive for the user, and if two or more sequential packets arrived with non-160 millisecond timestamps, the Cisco audio would be stopped for several seconds. Mark and I (mostly Mark) spent a significant amount of time over the last three days tracing the problem with ethereal, etc, and believe the issue has been resolved. Mark committed the changes to cvs earlier this afternoon. Testing from my * to digium (11 hops) today resulted in rock solid audio even with lag times ranging upwards of 500 milliseconds, and jitter ranging upwareds of 200 milliseconds. If you use iax2 and Cisco sip phones, please update from cvs and give it a try. I am not aware of any other sip phone vendor that is sensitive to these timestamps, but there could be others. Keep in mind the fix addresses iax2 timestamp problems at the distant end, therefore iax updates will be required at both ends of an iax link to address the end-to-end audio quality problem. Rich ___ Asterisk-Users mailing list [EMAIL PROTECTED] http://lists.digium.com/mailman/listinfo/asterisk-users To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [Asterisk-Users] IAX2 update - timestamp issue within iax pkts
Would this fix also help random quality issues both on a LAN and also with a remote SIP based installation running CVS from 3/22. We're having too frequent complaints in conjunction with Grandstream phones and very stuttery/choppy sound, usually outgoing to land lines, to the point of being unintelligible, but also on internal voicemail messages. Our voice LAN is a dedicated 100Mb ethernet switch for voice, and no general network traffic. Thanks, Ryan On Apr 14, 2004, at 4:26 PM, Rich Adamson wrote: For those that might be using Cisco 7940/7960 sip phones and placing calls across an iax2 link, we think the voice quality problem has been identified and corrected. The dev cvs should be updated as of about 3:30pm CDT today (April 14). snip If you use iax2 and Cisco sip phones, please update from cvs and give it a try. I am not aware of any other sip phone vendor that is sensitive to these timestamps, but there could be others. Keep in mind the fix addresses iax2 timestamp problems at the distant end, therefore iax updates will be required at both ends of an iax link to address the end-to-end audio quality problem. ___ Asterisk-Users mailing list [EMAIL PROTECTED] http://lists.digium.com/mailman/listinfo/asterisk-users To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [Asterisk-Users] IAX2 update - timestamp issue within iax pkts
I saw the message on the CVS mailing list, but it looked like it was only fixed in CVS latest, not CVS stable. Is this correct? Rich Adamson wrote: For those that might be using Cisco 7940/7960 sip phones and placing calls across an iax2 link, we think the voice quality problem has been identified and corrected. The dev cvs should be updated as of about 3:30pm CDT today (April 14). ___ Asterisk-Users mailing list [EMAIL PROTECTED] http://lists.digium.com/mailman/listinfo/asterisk-users To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [Asterisk-Users] IAX2 update - timestamp issue within iax pkts
No, this is an iax2-sip/rtp-Cisco 7960 problem. (Has nothing to do with LANs, Grandstreams, Snom, etc, etc.) Would this fix also help random quality issues both on a LAN and also with a remote SIP based installation running CVS from 3/22. We're having too frequent complaints in conjunction with Grandstream phones and very stuttery/choppy sound, usually outgoing to land lines, to the point of being unintelligible, but also on internal voicemail messages. Our voice LAN is a dedicated 100Mb ethernet switch for voice, and no general network traffic. Thanks, Ryan On Apr 14, 2004, at 4:26 PM, Rich Adamson wrote: For those that might be using Cisco 7940/7960 sip phones and placing calls across an iax2 link, we think the voice quality problem has been identified and corrected. The dev cvs should be updated as of about 3:30pm CDT today (April 14). snip If you use iax2 and Cisco sip phones, please update from cvs and give it a try. I am not aware of any other sip phone vendor that is sensitive to these timestamps, but there could be others. Keep in mind the fix addresses iax2 timestamp problems at the distant end, therefore iax updates will be required at both ends of an iax link to address the end-to-end audio quality problem. ___ Asterisk-Users mailing list [EMAIL PROTECTED] http://lists.digium.com/mailman/listinfo/asterisk-users To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users ---End of Original Message- ___ Asterisk-Users mailing list [EMAIL PROTECTED] http://lists.digium.com/mailman/listinfo/asterisk-users To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [Asterisk-Users] IAX2 update - timestamp issue within iax pkts
I saw the message on the CVS mailing list, but it looked like it was only fixed in CVS latest, not CVS stable. Is this correct? Yes, that's correct. Two issues: 1) the iax2-sip/rtp timestamp issue impacting cisco phones had not made it to Stable (yet), therefore todays fix does not need to be applied to compensate for that, and, 2) the root-cause problem (iax2 timestamp variation) is apparently in the Stable version. I'd have to guess and say this problem probably has been around since iax2 actually came into cvs existence. There could be some other problems resulting from the iax2 timestamp issues, but I'm personnally not aware of any. Do keep in mind that I'm not a developer and I don't do a lot of testing/playing/support for things that I don't have in our rather small environment (read-- I don't know for sure). I do know (from Mark) the timestamp diff of 20 ms between consequtive iax2 packets was the original design objective, therefore the fix corrects things to that objective. Rich ___ Asterisk-Users mailing list [EMAIL PROTECTED] http://lists.digium.com/mailman/listinfo/asterisk-users To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [Asterisk-Users] IAX2 update - timestamp issue within iax pkts
Rich Adamson wrote: For those that might be using Cisco 7940/7960 sip phones and placing calls across an iax2 link, we think the voice quality problem has been identified and corrected. The dev cvs should be updated as of about 3:30pm CDT today (April 14). Thanks Rich. I'll test this again next week when I get back to our lab. I hope we can close this issue once and for all. Regards, Andres ___ Asterisk-Users mailing list [EMAIL PROTECTED] http://lists.digium.com/mailman/listinfo/asterisk-users To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
