Teams rejects call with error 422

Occasional Contributor

Hi all,


I'm having some trouble with calling from a Swyx pbx to Microsoft Teams direct routing. 


When I place a call from Swyx pbx to Teams, the call get's denied. When I checked the logs I noticed the following:

422 Session Interval Too Small error


Teams is rejecting the call because Swyx is sending a 90 sconds field in the Session Expires Header. 

I searched the web for adjusting the allow Session Expire field in Teams but can't find anything.


According to this document:


The rule is to have at least a 90 seconds Header. So Swyx does nothing wrong with that.

Can anybody help me with this? Or point me in a good direction.




1 Reply

Hi @dvermeulen  If you don't get a timely response from this community, you might want to open a ticket at tech support, where authorized MSFT agents can troubleshoot an issue until it's resolved.