Forum Discussion
MS Teams Direct Routing - Internal call transfer failure
Yes, I'm using the same voice pattern, ".*" to send all digits without any normalization to our SIP trunk. You're right, maybe the issue is because of that, I will update voice rules tomorrow to make it strictly country-based, like '^+44.*' to see if that helps! Good point, mate!
Also, yes, SIP REFER shouldn't be coming back to PBX when we're doing an internal transfer from one Teams User to another one, but it does for some reason, that's the problem.
I'll let you know here how it goes and thanks for your reply!
Hi Sims,
I've removed the ".*" rule from my installation and created all specific rules for DIDs and still no luck, I can see SIP REFER coming back to PBX when I'm trying to transfer call that came from PSTN to Teams user. No luck here, unfortunately. Did you have any luck with this? Thanks.
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.
- How did you disable REFER? I mean - does your SBC sends some 4xx code when MS sends a SIP REFER message? Or somehow different? Thanks!
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.
