Teams rejects call with error 422

Copper 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.




3 Replies

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.

Has the issue been resolved, having the same issue.
Call forwarding to external number works but when the carrier sends a new re-invite Teams returns with 422 Session Interval Too Small and the call gets dropped.

This is my failed log, very desperate, MS case opened for a month now. 
---- Incoming SIP Message from to SIPInterface #2 (SIP_Teams) TLS TO(#919) SocketID(5762094) ---- [Time:16-02@12:32:31.466]

SIP/2.0 422 Session Interval Too Small
FROM: <sip:xxxxx
TO: <sip:+xxxxxx
CALL-ID: xxxxxx
VIA: SIP/2.0/TLS xxxxx
REASON: Q.850;cause=127;text="d71eea37-6fc6-4ddf-8291-dfb20edb98ff;Session Interval Too Small"
MIN-SE: 300
SERVER: Microsoft.PSTNHub.SIPProxy v.2024.2.6.5 i.EUNO.12