[Asterisk-Users] MTP required for CCM integration ?

[Dan Austin]

> Is it required to use an MTP on the Cisco callmanager, when
integrating
> with asterisk (using h323) ?
As of CCM 4.X, Cisco indicates that any H.323 trunk that will support
MoH/Transfer/etc need MTP resources.  Annoying.  

> I am working on a project where the goal is to interconnect Cisco
> Callmanager (version 4) clouds together, using either SIP or IAX
between
> multiple * servers. Basic setup will be:

> PHONE - sccp - CCM (V4) - h323 - ASTERISK - iax - ASTERISK - h323 -
CCM
> - sccp - PHONE

> I am working on the first half of it, which is:

> 7920 --- SCCP --- CALLMANAGER (V4) --- chan_oh323 --- ASTERISK 1.0.9

> I want to avoid the use of a gatekeeper.

> In that configuration, I am trying to get call transfer working. The
> phone can call the DEMO app on asterisk, but then I cannot transfer
the
> call to another Cisco phone (on the same callmanager). I have some
PCAP
> traces if required. Basically, the 2nd phone rings, but there is no
> audio channel. After about 10 seconds, I see that that chan_oh323
hangs
> up the call.
Sure will drop the call.  MTP does solve this.

> The idea was to avoid RTP streams through the call manager.
Good plan, and one that I would consider a must for scalability
and quality.

> Now, if I define a Media Termination Point (MTP) on the Callmanager,
> things work much better.

> I have also tried the new ooh323 with 1.2.0-beta1, but I couldn't get
> audio at all.
Odd, I am using ooh323c.  I have a special test release, but the fixes
for our CCM4 enviroment were added to CVS.  Are you using ooh323c from
Asterisk-Addons or a download from Open Systems? 

> I have read a lot about people having success with integratin CCM and
*,
> but without any details, especially around MTP configuration.


> Any help would be greatly appreciated. BR, - Patrick -

http://bugs.digium.com/view.php?id=5374 has a patch that allows *
to send RTP packets when it is not receiving them.  I wasn't expecting
this result, but applying this patch resolved the disconnect when a
SCCP phone put a call on hold and allows transfers.

The bug/patch got quite a bit of early attention, but seems to have
languished.  Try it out and provide feedback.  Maybe enough success
reports will help get it rolling again.

Dan