Teams Direct Routing Extension Transfer Failed

Adityo Prabhaswara H. 

I was also living under impression that life could be easier with Transfer to Teams user 🙂 no way

Teams counts on fact that you wanna have in hands how the REFER message will be handled but they also count on that you will send them the REFER back to handle it properly. No matter if it is user or extension on your PBX it will simply all the time send the REFER to your Teams SBC.

I would recommend to setup on Teams SIP interface (IP Profile) to "handle locally" REFER messages and the same thing also to setup on PBX interface (IP profile). If you have setup already REFER rule in ip routing which should resend all REFER messages to Teams proxy then it should work as described earlier. 

I currently have such behavior:

Teams user transfer PSTN call to user -> SBC catch it -> send back the REFER to Teams -> Teams handle REFER inside 

Teams user transfer PSTN call to PBX extension -> proper dial plan needs to be set to normalize number -> SBC catch it -> send back to Microsoft Teams proxy -> Proxy creates new invite and send it back to your SBC -> SBC handle it as new call to local PBX 

Teams user transfer PSTN call to Teams user extension -> proper dial plan needs to be set to normalize number -> SBC catch it -> send back to Microsoft Teams proxy ->Teams handle it as number of Teams user

All is just based on current findings of my setup. One checkbox in different way and you can have different behavior. 😉 

BTW. I am doing integration with CUCM and also with Openscape Voice in three regions differently. So no worries I have my headaches too 😄