Setup: Asterisk server in NY. Cisco 7960 IP Phones in NY and London. Dedicated T1 from NY to Ldn. T1: Latency - 100ms Qos applied No errors Default codec on Ldn IP Phones = g711alaw Default codec on NY IP Phones = g711ulaw Both codecs allowed on each phone. Issue: Calls on IP Phones from NY to London hear clicking noise on NY end. Anyone experienced something similar or can offer some assistance? Thanks, Taf.. Send instant messages to your online friends http://uk.messenger.yahoo.com
Hi Carl -> Setup: > Asterisk server in NY. > Cisco 7960 IP Phones in NY and London. > Dedicated T1 from NY to Ldn. > > T1: > Latency - 100ms > Qos applied > No errors > > Default codec on Ldn IP Phones = g711alaw > Default codec on NY IP Phones = g711ulaw > Both codecs allowed on each phone.I'm guessing you're connecting the boxes with IAX. Three questions: 1. What sort of QoS are you using (i.e. what are you tagging on - a tos bit, port number, etc)? 2. What's your routing equipment? 3. Is there other traffic on this T1? If so, what?> Issue: > Calls on IP Phones from NY to London hear clicking > noise on NY end.But not the other way around? Hmm. Does the NY box host any other phone traffic? Any analog cards? Have you tried connecting just a basic IAX softphone to the NY box - does it suffer the same issues? - Noah
Hey Carl -> In answer to your questions: > > Calls over T1 are plain old sip/rtp no iax. > Qos - priority queue end to end > Routing - 2800 router each endCan you confirm on the Cisco that you are successfully tagging on the VoIP traffic? I think I remember you said there were no QoS errors, but you can also watch the packets going through the QoS rule (can't remember command right now, but I'll look it up).> Other Traffic on T1 - Yes usual MS stuff.Aha! How much traffic and what sort is it? Anywhere near saturation?> Thinking it might be a transcoding issue.Sorry, I don't remember if you mentioned this, but what is your hardware setup, and how many calls do you have going through the T1 link? What codecs are you transcoding to/from? - Noah