Forum Discussion
MS Teams Direct Routing - Internal call transfer failure
Lt_Flash I had no luck with changing the voice route, so ended up raising it with MS support.
Apparently if you disable REFER as an allowed method within your SBC's signalling messages, then MS Teams does not use REFER for transfers and just re-INVITEs to the SBC. That way the internal transfers work perfectly fine.
No, not by rejecting the REFER with a response code. I basically did a message manipulation rule to re-build the Allow header for calls to MS Teams without including REFER. Which vendor are you using? If you have an AudioCodes as well, I can give you the rule syntax.
Hi could you please share the syntax? I am in the same boat, many thanks in advance.
Paula
i have the same issue, could you please send me the manipulation you did to the response
You need to modify 'Allow' header in original message coming from MS Teams to your PBX, removing 'REFER' method and then in any responses from PBX you also need to remove 'REFER' method. In this case MS Teams will be sending Re-INVITE packet instead of REFER packets. Hope this helps.
Hi, We are having a similar transfer issue and I see you have the Audiocodes syntax to remove this in the ALLOW header. Any chance you could send this across so I can try this?
'No, not by rejecting the REFER with a response code. I basically did a message manipulation rule to re-build the Allow header for calls to MS Teams without including REFER. Which vendor are you using? If you have an AudioCodes as well, I can give you the rule syntax.'
Cheers
Darren
Have you setup on the opposite trunk (IP Profile for provider SIP trunk or your internal PBX not Teams side) Handle Locally of the REFER messages?
This will do the same job basically and you do not need this special manipulation which I personally consider as too much because it does not give you any chance then manipulate REFER messages.
So for IP profile of the SIP trunk towards your provider/on-prem PBX
I would setup these parameters on Audiocodes SBC
Remote REFER Mode Handle Locally Remote Replaces Mode Handle Locally Play RBT To Transferee Yes Remote 3xx Mode Handle Locally
