Issue with SIP Trunk between cucm and Mitel phone system

[carl_townshend]

Hi All

We are having issues with our SIP trunk between our CUCM v11.5 and a Mitel phone system.

If we call them from older SCCP phones, the call works fine, however when we call them from our SIP 7841 phones we get no audio.

When I look at the packet capture, when dialling the SIP phones, our system is not sending them a 200 OK SDP message.

Any ideas why this is?

The one that's works is at the top, the failed one at the bottom

[Nithin Eluvathingal]

Check the Route between 10.18.60.11 --- 172.30.240.X. Looks like 10.18.60.X doesn't have a route to 172.30.240.X network. Two way communications should be there between all your voice subnets.

[carl_townshend]

Hi There

The route is all in place.

My thinking is that the SIP phone is not sending the 200 OK?

With the SCCP phone the call manager has to send it, where as with SIP it looks like the phone sends it.

SIP profile setting on the phone maybe ?

[Nithin Eluvathingal]

Enable Media termination point required on SIP trunk and apply MRGL. Restart the trunk . 

[Mohammed al Baqari]

Hi,

Check on Mitel why its not responding with 200OK. Because this is missing
the call isn't established. The suggestion in the other post of using MTP
might work but not practical. You need to find the reason for Mitel not
responding.

Compare the invite of the working and non-working call. I suspect that 7841
is sending a header which Mitel is not happy with hence not accepting the
call.

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[carl_townshend]

Hi

in the first trace, the call manager responds with 200 OK (The cucm is the 172.30.208.17 ip)

In the second trace when calling a 7841, the CUCM does not respond.

Why would this be?

Surely the signalling should only come from the CUCM and not the phone itself for calls over the trunk?

[Mohammed al Baqari]

Oks. In this case, from RTMT generate SIP diagram to see why CUCM isn't
sending BYE. Go to Voice/Video > Call Process > Call Activity > Session
Trace Log View > Real Time Data.

Filter your call based on calling/called numbers and see the messages on
CUCM.

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[carl_townshend]

Hi

please find attached trace of the mitel system calling us (cucm)

[Roger Kallberg]

Have a look at this document to see if you’re setup is the same. http://www.mitelforums.com/articles/3300/mitel-3300-Cisco-CUCM-SIP-Trunk-Configuration-guide.php

[carl_townshend]

Hi

I will check this, cheers

Just another question, the only phones what work are SCCP as per the packet capture above, we can see the CUCM responding with the 200 OK SDP message.

When we make a call to the SIP phones, should the call manager respond with the 200 OK SDP message as per the first capture, OR when its a SIP phone, should the SIP phone respond with the 200 OK SDP message?

[Nithin Eluvathingal]

Have a look on below link. its a blog from @Mohammed al Baqari 

http://tek-board.blogspot.com/2015/09/cucm-sip-early-offer.html

[carl_townshend]

Hi

I tried both the options on your link and still no joy.

We still do not send the sdp message back to the Mitel.

Any other ideas ?

[carl_townshend]

Hi

Can anyone pls help with this?