MTP causes issues with T38 switchover

[jsanders]

David Hanes mentioned that MTPs and transcoders sometimes cause issues in FoIP switchover for standards based T38. Does anyone know why or if there is a workaround? I need an MTP for this particular SIP trunk but also want to use T38. As long as the MTP is in the call flow, the T38 switchover fails.

[simon.granger]

Hi

I was just wondering if you managed to get this to work? we have exactly the same issue.

Thanks

[jsanders]

I did not. We ended up redirecting the fax calls at the CUBE to another CUBE(running on the MTP routers) and bypassing the UCM all together.

[wilson_1234_2]

Hello,

I am new to voice and was curious about this:

"I need an MTP for this particular SIP trunk but also want to use T38. As long as the MTP is in the call flow, the T38 switchover fails."

Can you explain this?  Why do you need and MTP and how did it get in the call flow?

[Steven Smith]

You could try using an MTP on a router and having codec pass-through setup under that MTP.