Exchange Unified Messaging

[Chakara]

  This one is interesting.  I have a small 3300 with PRI.  All sets are 5340's.  Exchange is their voicemail over SIP trunks.   Here is the scenario:

 - Receptionist receives a call from the PRI
 - Desired destination extension is busy (all users have single line only for prime)
 - Receptionist initiates a transfer (either with DSS/BLF or X-fer key)
 - Receptionist hears the beginning of the users greeting (IE: from the Exchange mailbox)
 - Receptionist completes the transfer (either with "Release Me" or by hanging up)
 - Call drops.
 - Exchange logs a Fax communication error (at bottom of post)

This strange behavior also happens if you attempt to build a 3 way conference between the PRI, and extension and the Exchange server - the connection to Exchange drops.

A bit of reading shows that Exchange does not do fax tone detection, but does support T.38.  To me it seems that the 3300 is presenting the call as a T.38 fax rather than a voice SIP call, but dunno.  I've sent a Wireshark trace to Mitel support but thought I'd run it by your guys.....

Any ideas?

-Chak


(in the below errors, 10.10.10.10 is the 3300 icp)
------If Exchange T.38 Fax is disabled
* Event ID: 1033
* Source: MSExchange Unified Messaging
* Description:
* The Unified Messaging-enabled user "Shannon Wong" is
* not configured to receive fax messages. The fax message that
* originated from phone number "Anonymous Caller", destined for
* extension "8000", was terminated. To resolve this issue, use the
* Exchange Management Console or the Set-UMMailbox cmdlet to enable
* the user to receive incoming fax messages.
* Or
* --------If Exchange T.38 Fax is enabled
* Event ID: 1150
* Source MSExchange Unified Messaging
* Description:
* The Unified Messaging server was unable to create a
* message for the fax call with ID "7968032-61458883@10.10.10.10". The
* following invalid media details were received in the session
* description: "v=0
* o=- 2385 2386 IN IP4 10.10.10.10
* s=-
* c=IN IP4 10.10.10.10
* t=0 0
* m=audio 50088 RTP/AVP 0 8 101
* a=rtpmap:101 telephone-event/8000
* a=fmtp:101 0-15
* a=X-mitel-dtmf-type: std mitel inband
* a=X-mitel-crypto:1 AES_128
inline:xQYR6PRb3WWtBD3t7ipGnNOlBUSaiZiaAAAAAAAAAAA3xcwFz imV6GhyTXjmyQ
* AA:|0|
* a=X-mitel-crypto:2 NO_SECURITY
* ".

[chadmaynard]

Does the decode of the SIP session show a REINVITE from G.(whatever you are using) to T.38 ?  If so which party is requesting the signaling change? Exchange 2007 with SP1 will do inband fax tone detection and media negotiation. You need to do this on one side or the other, probably on the Mitel side if you are already using it there... If you are detecting faxes in the 3300 you should disable it on exchange. When exchange gets a sip reinvite from the mitel to T.38 media it will wait for a fax whether it receives a tone or not. If there is no fax involved at all then either the dial plan is forcing T.38 or some option in the PBX is forcing it.

[Mattmayn]

Are you sure that it is not something simple in one of your COSs like say, Public to Public connection allowed?

I could be way off base here but it almost sounds like this is what is happening.

[Chakara]

Matt, I checked that - remember that if you call a non-busy extention it will redirect and work correctly. 

Chad,  I'm attaching the trace if you are interested.  The trace is from the perspective of the 3300 and is fitered for only traffic that goes to the Exchange.  (10.10.10.10 is 3300 and 10.10.10.3 is Exchange).

Looking at the trace I don't see any REINVITE - Just INVITE and BYE.  I did not turn on fax tone detection on either device - we don't need/want that.  But perhaps it is on by default on the Exchange?  Not sure but will check that.

Thanks for the feedback guys - right now I'm seriously thinking about calling up Microsoft....

-Chak

[ralph]

Chad,  I'm attaching the trace if you are interested.  The trace is from the perspective of the 3300 and is fitered for only traffic that goes to the Exchange.  (10.10.10.10 is 3300 and 10.10.10.3 is Exchange).

Chak,
How do see the uploaded traces?   I don't see any link that would give me access to it.

Ralph