Hi All,
Strange problem here. We are having intermittent issues where as when an extension phones another, only one side can here the call, or only one side can hear the call initially and then after a few seconds both sides can hear the call. We have spoken with our Telecomms engineer, who had a look at the Mitel and stated that nothing obvious is causing the issue and it is probably network related. We have checked the network switches involved (HP Procurve), and they are not reporting anything unusual either.
I have run a wireshark capture and managed to capture at a time when the problem of one side not being able to hear the other for a little while. I can see the conversation between the originating phone and the telephone system and then the conversation between the two phones. If I decode the UDP packet as RTP and then analyse the streams I can see both streams are there, however I can also see that some of the audio in one direction is missing at the beginning of the call, which matches what was experienced. How do I go about diagnosing / fixing this issue? Is there documentation that describes the call setup phase / handoff / describes the communication between the two phones. That may help me to see what is going wrong.
I can see in the packets that the Differentiated Services is set to EF on the packets and that the switches by default have not had their setting changed (a specific VLAN for voice has been setup). As far as I can see therefore the Voice traffic has the correct QOS setup and shouldn't be dropped even if the switch is busy.
Anyhow any help very much appreciated.
Thankyou,
Paul