Forum Discussion

Copper Contributor

Jul 15, 2019

MS Teams Direct Routing - Internal call transfer failure

Hi all, My organisation is planning a move to direct routing. We have an AudioCodes VE SBC. I've been working on this for awhile and got everything to a pretty decent state. I've come across ...

microsoft teams

Lt_Flash

Brass Contributor

Oct 03, 2020

davidmcgrath

Sorry, somehow I have missed your reply and didn't receive a notification about your answer. You need to block 'REFER' method in both initial requests coming from PBX or MS side and in replies too, in that case MS will be sending just Re-INVITES as per my SIP dump above. But currently, in October 2020, it looks like they've fixed REFERs, we're actually testing if they're working fine now, but haven't come to conclusion yet. Looks like REFERs are working, but we haven't finished full testing procedure in our company.

DaveChomi

Iron Contributor

Nov 28, 2020

Lt_Flash
I don't see any issue with REFER over the last year on our infrastructure and we are using almost every type of DR configuration even with Local Media Optimization and proxy SBC. The only issue I had with REFER was that our firewall was setup all the time wrongly for mediabypass (first version) when SBC wanted to reach it's own public IP for media flow and crazy hairpin was needed over the FW.