P Series SIP Trunk Failed Checklist



  • Model: P Series PBX
  • Issue: SIP Trunk Setup Failed



There are several kinds of trunks that can be used on the PBX side.

  • Peer Trunk
  • Account Trunk
  • Register Trunk


There is also a special trunk that may be used on P Application Edition and P Software Edition PBX which use the SIP Dedicated Line. We call it SIP Dedicated Line Trunk. 


If you are not familiar with the types of trunks, try to refer to the below guide.

Different Scenarios of SIP Trunk Registrations



1. Check the information of the trunk.

Make sure the information (transport/domain/IP/port/username/password) of the trunk is correct.


If you are using register trunk, you can try to register the trunk on an IP phone/ softphone for a test. 

If failed to register as well, you can double-check with the trunk provider.


2. Check the network.

Make sure PBX connects to the Internet and the DNS server setting is correct.

·  When the trunk you are using is a domain, try to ping it to check if the Domain can be analyzed and get a reply or not.

·  When the trunk you are using is an IP, try to ping it to check if you can get a reply or not.

If not, you have to check the network first.



3. Check the firewall on PBX.

Have a double check on the router as well to make sure there is no restriction for them.



4. Check NAT setting only when you have enabled it.

The wrong local network added may cause the trunk failure as well.

If you don’t use it, you can ignore it below.



5. If you are using SIP Dedicated Line Trunk, refer below.

The SIP Dedicated Line often be used with a peer trunk.

The difference is this trunk is based on using the sip dedicated line on the WAN port with Dual Mode of Network on PBX.

So we have to pay attention to the Static Route setting on PBX.



6. A Known Issue:

When you are using P Cloud PBX integrated with Yeastar Gateway Product with 401 authority error, plz refer to the below to get the firmware of Gateway.

Dedicated Firmware


More Information:

The below article contains several cases of SIP Trunk failure which you can refer to.

SIP Trunk Registration Troubleshooting Guide Content


In The End:

Still failed? Get the below log and contact us!

We need PCAP+System Log to check in advance.

(1) PCAP

Try to disable the trunk and re-enable it when capturing the PCAP.


(2) System Log


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