Getting a SIP 403 from Teams Direct Routing and debug/logs are worthless

[Anorton1]

We are getting the following 403 and need assistance on dete

SIP/2.0 403 Forbidden

FROM: "CINCINNATI,OH"<sip:+15135557313@customer1.sbc1.directroute.com>;tag=gK0006d317

TO: <sip:5135550967@sip.pstnhub.microsoft.com>;tag=2f3f23b461d8472ca560abe407d5cff2

CSEQ: 30117 INVITE

CALL-ID: 186679315_39318390@8.8.8.8

VIA: SIP/2.0/TLS 8.8.8.8:5061;branch=z9hG4bK00B06f1288e6986b1e9

REASON: Q.850;cause=63;text="57a3b8c8-386c-4cbf-bb46-8c8ea150bbee;Current call site state prevents fork to this entity."

RECORD-ROUTE: <sip:sip-du-a-us.pstnhub.microsoft.com:5061;transport=tls;lr>

CONTACT: <sip:api-du-b-usea.pstnhub.microsoft.com:443;x-i=57a3b8c8-386c-4cbf-bb46-8c8ea150bbee;x-c=a9f7ba1c16b556bc83765fe3b6e87180/s/1/ca57a5aa43874096aa09d6791488907b>

CONTENT-LENGTH: 0

ALLOW: INVITE,ACK,OPTIONS,CANCEL,BYE,NOTIFY

SERVER: Microsoft.PSTNHub.SIPProxy v.2021.2.9.1 i.USEA.9

[#2]

Please share the value for
Users > Select affected user > Policies > Calling policy -PreventTollByPass

[#3 · Accepted solution]

If you see a 403 error in response to difficulties placing calls see if you are also noting a Q850 response from Microsoft.

Explanation

Q850 responses provide reason codes which may also carry verbose detail on the cause for the rejection.

Some diagnostics may be necessary to establish the reason why Microsoft are rejecting a call and where we can we will offer suggestions as to how these can be resolved.

Example

Reason header: Q.850 ;cause=63 ;text="9810e5a9-667c-4513-8d3a-5d83503e1c71;Current call site state prevents fork to this entity." 

Possible solution: AllowCallingPreventTollByPass Setting