Call2Teams - Customers
There are several reasons why an inbound call may fail to reach your Teams device.
In the first instance, please read this article: Inbound/Outbound Call Issues
Shown below are a few examples for why you may not be receiving calls. Often, looking into the call logs as described in the linked article above, will shed some insight into these.
TABLE OF CONTENTS
- Applies To
- Registration Timeouts
- 403 Permission Denied: No Match for Service User Part
- 403 user Not Enterprise Voice Enabled
- 404 Not Found Errors
- 422 Session Interval Too Small
- 488 Not Acceptable Here
- 504 Couldn't Classify Packet or No Response
- Q850 Codes
- SIP Codes Wiki
- SIP Methods, Requests & Responses
If your registration times out, your Teams device will not be available to receive calls. This may be noted as an intermittent ability to receive calls.
Hover over the Registration indicator in the Users section of the portal and check the 'Next Sync' advisory.
Ideally a shorter Sync time of 5 - 10 minutes is advisable to prevent timeouts.
You should amend this setting.
403 Permission Denied: No Match for Service User Part
This error usually means the number offered by the PBX or Trunk for a user is incorrect. It is most likley to be caused by E164 number mapping issues. refer to this article for help: e164 number formatting
403 user Not Enterprise Voice Enabled
This error is presented when there has been an amendment to the User's Phone Number which has resulted in their not being enabled to pass PSTN traffic. Please check the user's phone number in the Teams Admin portal matches the number in our portal. To realign these, manual amendment and a fresh Sync may be required. Alternatively, you can run a PowerShell command to amend the MS configuration.
404 Not Found Errors
These are errors produced when the user referenced in the INVITE are not allocated against the end system , also if there are no route for the dialed number.
422 Session Interval Too Small
This error relates directly to the MIN-SE and Session-Expiry settings in the INVITE header.
The Min-SE can be left at the default of 90 in most cases, but the Session-Expires needs to be set to at least 1800 to allow for the exchange of INVITES and Re-INVITES.
488 Not Acceptable Here
504 Couldn't Classify Packet or No Response
This is likely to be a mismatch between the IP address used when Call2Teams registered with the PBX, and the PBX IP address being used for the call delivery.
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.
Reason header: Q.850 ;cause=63 ;text="9810e5a9-667c-4513-8d3a-5d83503e1c71;Current call site state prevents fork to this entity."
SIP Codes Wiki
This link will take you to an external Wki listing all known SIP codes and their meanings. SIP Codes Wiki
SIP Methods, Requests & Responses
You can read more on SIP Messages here.
Please note Qunifi cannot be held responsible for the content of any third-party documentation offered.