Sip trunk issues

[Ceaserx]

Hi

I have a client that we need to connect to a telco via SIP trunks but we have been experiencing some weird issues. It's a 3300 CX2 running MCD6.The SIP link establishes fine and we are able to make calls on three IP phones with audio. No other devices can then connect a call with audio. At first we thought it could be a bandwidth issue but even when those three devices are then not connected we still can't make calls on other devices. The system has 10 SIP licenses so that's not the cause either.It only allows the first three devices to make calls. When rebooting the Mitel and the Telco router three other devices can then connect and nothing else again. When you have a working call and transfer the call to another phone we experience no audio as well. We started off with MCD 5 SP2 and I upgraded earlier today to eliminate the software version.

The Telco say they are not using NAT and that it can't be an issue of not allowing the whole subnet. I have done wireshark traces on working and non working calls but can't see any difference. The trace indicates G.729 is being used in both working and non working calls. We have played around with most settings under the SIP peer profile but it makes no difference.

Any ideas or suggestions that i can put to the Telco?

 

[619Tech]

Was this an existing SIP connection, or is it new? Check your SIP Peer Profile and make sure you have "Maximum Simultaneous Calls" set to 10. Who is the carrier?

 

[TLDuk]

If you mirror the port that connects to the edge router to the port your wireshark PC in running you should be able to capture the audio stream and play it back check this first..

I need to check my notes but i noticed some strange things when setting up sip recently i will check later and com back to you

If its not broke tweak it..