Avaya Session Manager and CUCM 8.x

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Aug 5th, 2010
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Has anyone had troubles getting the SIP trunk to work properly between these two systems?    The trunk seems to work, but the RTP stream is avoiding the Avaya Session Manager completely.  From what i can tell, the SIP packet is getting changed on the user agent and marking the destionation as the CUCM rather than the Session Manager.  So the RTP stream goes from the end device on Avaya to the CUCM.   Basically, we are trying to trunk the call between the PBXs so RTP flows from one system to the next... not around the Session Manager.

CUCM----SIP trunk-----Session Manager-------SIP trunk------Exchange UM.

When a call rolls from CUCM to Exchange UM, the signalling goes through, but the RTP stream goes from Exchange UM/CUCM.

I have MTP setup on the CUCM trunk SIP to Session Manager, but the RTP stream still goes around Session Manager. 

Im guessing its an Avaya problem, that they are manipulating the SIP header to make the RTP packet go back to CUCM and not through their system for some reason.

Fun stuff right?!

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Wes Sisk Thu, 08/05/2010 - 08:22
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I am a bit confused by your question. In that scenario the 'natural flow' would be for RTP to flow directly between the ipphone and ExchangeUM.  Forcing MTP on CUCM forces the RTP to flow through CM's MTP resources (on the CM if using software mtp, otherwise hardware mtp on c6k or ios).  None of this would force RTP to flow through session manager. If you want to force RTP through session manager then session manager is the one that needs either MTP resources or to behave as a session border controller.

The default in most voip call control protocols is to establish RTP directly between endpoints bypassing the potential bottleneck of central control.

dpaquet Thu, 08/08/2013 - 20:11
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I'm trying to get the same configuration working.  Do you have examples of the configurations.  I'm having problems with the MS UM platform rejecting the call setup.  "Options unavailable"


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