Mitel 3300 MXe dropping SIP calls

[donschult]

I'm experieincing an issue on our Mitel setup where phone calls using a SIP channel are being dropped after 30 to 40 seconds by our service provider because our Mitel controller is not sending back an acknowledgement in the call setup (this is the explanation form our service provider). 
I'm not 100% convinced this is the reason but they have done a wire shark trace that shows after the call is established the service provider sends repeated 200OK commands but never ereceives an ACK comman from the Mitel so the service provider will automatically terminate the call after 30 to 40 seconds in order to prevent a situation where the call is kept online for an extended period that will create a huge telephone bill.

You should be able to download the trace at the following link: https://www.yousendit.com/download/QlVqS3dqY1NuSlJFQmRVag

Fortunately we've got a mix of SIP and analogue channels so we do have the ability to call out but with more staff moving into our building we want to be able to utilise the SIP channels more and generally a phone call is not 30 to 40 seconds.
The servie provider reccomends we upgrade our software version on the Mitel, which is fine, I don't mond doign this but I know of other sites on the same version as us with SIP channels and they don't have these problems.

MCD Release 4.0 SP1 (ICP Call Control 40.0.1.16_SP1)

Any thoughts you guys have on this would be great

[bluewhite4]

If you have access to the other systems, compare their SIP Peer Profiles to your systems. Sounds like an option might be different between the two.

[martyn]

It does sound like a setting in the SIP peer profile that would be the cause of the issue. Are you able to post some shots of that form so that we can narrow things down from there?

[donschult]

Apologies for the late reply.

We decided last week to do an upgrade on the controller to the latest version and (touch wood) it seems to have resolved the issue.  I've confirmed both with Mitel locally and with our ISP that the SIP peer profiles are correctly set for the service we are using so it seems to be directly related to a software issue on the Mitel side although I still firmly believe that our service provider has a lot to do with the issue.

Thanks for your replies.

[ralph]

I've seen similar issues with both Juniper firewalls and InGate Siperator.   The juniper had a tic box that needed to be checked after about 30 seconds and the InGate had a bug that dropped the call after 7 minutes.

Ralph