Applies To

Call2Teams - Customers


Registration can refer to two separate, but related things:

  • PBX and Trunk Service Registration refers to the need for those entities to register with the service.
  • User Registration refers to the service user successfully registering with the PBX/Trunk.

This article lists diagnoses of common issues with registration, and provides advice as to how to resolve them.


PBX/Trunk Registration Diagnostics

Diagnostic: Domain

Ensure that the customer's domain resolves correctly for PBX/Trunk realm or proxy if used, use this link to check: DNS Lookup

If users are stuck in the 'First Registration Queued' stage, this can be because of DNS issues, caused by the service being unable to resolve the settings entered to a valid SIP endpoint.

The service attempts to use SRV records (if available), otherwise it will fallback to using A records. Please check these are correct before raising a case.

Diagnostic: Firewalls

Ensure that the customer's firewall is not blocking any of the service's SBC IP addresses. These are listed on the service portal: Navigate to Services > PBX/Trunk

Note that these IPs are only used for SIP signalling. The call media can come from different IP addresses -adding said IP addresses for RTP to an allow-list during a call is not recommended.

Try clearing NAT sessions on the customer's NAT device (such as a firewall or router). If the NAT device does not support clearing NAT sessions then a reboot may be required.

Try changing the affected customer/user's PBX/Trunk location. Save this change, change the location back, and save again. The SBC Addresses (mentioned above) should change. 

If this resolves the issue then it indicates that you the firewall/NAT device may have blocked some of the service's IP addresses.

Diagnostic: Credentials

Double check the affected user's authentication credentials to ensure they are correct. 

This can be tested by using the credentials on a soft phone to confirm registration. If the soft phone registers correctly, ensure the credentials match those entered on the service portal for the affected user.

Diagnostic: Security Certificates

If the customer is using TLS, check that the SSL certificates meet the service criteria:

  • The Certificate type must be PKI that are issued by a recognised certificate authority. They must not be self-signed.
  • The Certificate must be served directly - it must be served by the PBX/Trunk, not just trusted by the PBX/Trunk.
  • The customer's PBX/Trunk must support TLS v1.2 or above.
  • Check the SSL status at the following site: SSL Checker
    • If the customer uses a firewall, it will need to allow access.
    • Ensure all sections have a green tick.

Diagnostic: Ports

Check the port(s) the customer's PBX/Trunk is expecting to communicate over.

On the service's side, this is shown on the services > PBX/Trunk page in the service portal. 

This will show the IP and port the service uses for communication. 

This is where incoming calls should be sent and the IP where the service will originate outbound calls. 

Note: The port is non-standard.

On the customer's PBX/Trunk, the port will be given in the SRV record. 

If the customer is not using SRV then the service will use the A record result to find the destination IP and then use port 5060

Users can amend the domain/IP address in the proxy field on the service portal page with :<port number> if it is needed to specify a non-standard port.

Ensure the transport the customer uses matches the settings on the service portal. If the transport is not known, start with UDP.

Check the specification given by the customer's PBX/Trunk provider, and ensure that the Call2Teams Authentication Types offered can be supported.

User Registration Diagnostics

Diagnostic: Registration Status

Check the Registration Status of users from the Users tab of the service portal:

If the status is showing Green, then the system has successfully matched the credentials of the user to a PBX or Trunk entry.

If the status is showing Amber, this indicative of the initial registration being stuck. This may be due to DNS records. Please ensure these are correct and that enough time has passed to allow for propagation before raising a case for investigation.

If the status is showing Red, then registration is failing. Hover over the status indicator for more information; a tooltip will show:

The tooltip should give an indication of the issue. 

In the screenshot above it shows "Unauthorized". This means that the SIP username and password combination do not match those held by the PBX/Trunk Service and must be amended.

The message may also display "No response received after 10 seconds". 

This happens when a REGISTER packet is sent to the PBX/Trunk but no reply was received.

If a registration issue persists, customers may need to raise this with their PBX/Trunk supplier.

Click the link on the tooltip to launch a diagnostics page:

Ensure the user's SIP username/password/domain matches a user on the PBX/Trunk.

Ensure that the proxy port is correct - the default (5060/5061) may be rejected by the PBX. 

Enter the SIP Proxy so that it includes the preferred Port, for example:

The REGISTER contact header received by the customer's PBX may be too long. Try amending the following setting on the PBX configuration page on the service portal: Suppress Contact Data Param - this is shown in the screenshot below:


Please note Destiny Automate Ltd. (formerly Qunifi Limited) cannot be held responsible for the content of any third-party documentation offered.