Mitel 3300 MCD

[pbxnkey]

I have a customer with multiple sites networked and using a centralized server. When any of the remote sites calls the main site the audio gets choppy intermittently. The choppiness is only heard at the remote site though. Remote site to remote site is just fine.
All sites are using Mitel TDM phones connected via fiber to sx-200 nodes.
When capturing packets I do not see any retransmissions on UDP packets.
I did notice that in the captures that the Mitel was using g.729/g.711 interchangeably.
The customer has indicated dropped packets when pinging the remote sites.
Is there anywhere that I can set the codec to always use g.729?

 

[dbijen]

UDP-packets don't get retransmitted, that's how UDP works.

What type of connection is used between the sites? If this is IP-based, is QoS configured? Can you test call quality outside business hours, when there's possibly less other IP traffic?

In MCD, intra-zone compression is configured in Voice Network - Network Zones and Users and Devices - Location Specification.
By default, compression is used between zones and if compression is available at both endpoints.

 

[pbxnkey]

You are correct on UDP. My mistake, it was a TCP retransmission probably between the 2 MCD's. I did not save the capture so I cannot look back.
Between the sites they are on an MPLS network. QoS is enabled for 75% bandwidth.

I looked at the manual before posting this thread and did notice that section on compression between zones. I changed the the main site and 1 remote site to zone 2 and In the Network Zones page for Zone 2 I changed it to Yes.
We tested making a call between sites and same problem (broken up audio).
For Compression the manual only specifies the Zones for IP phones but I figured there must be a way to do it for trunks also, but I could not find it.

 

[LoopyLou]

Stupid question: do you have a DSP module and compression licenses on the 3300's that you want to run compression between?

IP sets establish their own compression between themselves without using resources on the 3300. TDM devices attached to a 3300 will neet to make use of the compression generated by the controller itself. This requires a DSP module and compression licenses on each 3300 controller.

I ask because you didn't say.

I'd tell you a UDP joke but I'm afraid you won't get it. TCP jokes are the best because you always get them.