Can't make calls out to the public network

To troubleshoot an outbound call issue please verify the following:  Are calls reaching the EasySBC, and if they are, where is the call failing?

How to check this: Go to Status and then Call data records on your EasySBC. Here you will see all call activity along with "cause codes" indicating an issues with a call.

You will see that in the DIRECTION column the calls are tagged as IN or OUT.  The IN tag tells you origin of the call.  This may be internal (from your VoIP system) or external (from your SIP trunk provider).

Note the time of the last call record and then place a call from your internal phone system to an external number.

There are 3 possible outcomes for this test:

  1. The test call does not show as a Call Data Record - there is a configuration issue on the internal VoIP system as calls are NOT being sent to the EasySBC.
  2. The test call appears but only an IN record is shown - there is a configuration issue on the EasySBC
  3. The test call is shown with both IN and OUT records - there may be an issue with the EasySBC configuration OR the SIP trunk providers configuration


Here in this example, using the top call data record, we can see that:

  • calls are reaching the EasySBC
  • the call originates from internal (Direction = IN)
  • the call is passed to the SIP trunk provider by the EasySBC (corresponding OUT call)
  • the calls to the Provider are failing due to a Forbidden (403) error.
  • EasySBC returns a failure code (481) to the internal VoIP System

In this instance we see outcome number 3, the error is either a configuration issue on the EasySBC or the SIP trunk providers network.

Based on the outcome of you test call please see below for advice on how to proceed:


Outcome 1: No call appeared in the Call data record list

The call is not reaching the EasySBC.  Verify the following:

  • The SIP trunk configuration on the VoIP system sends calls to the IP address of the EasySBC
  • The EasySBC is reachable from the VoIP system (try to PING the EasySBC from the VoIP system)

Outcome 2: CDR appears but only an IN record

The call is being rejected by the EasySBC for some reason.  Most likely cause will be the SIP domain being used by the VoIP server.

The following screen shot shows a failed call and the highlighted RED area shows the SIP domain being used is

This SIP domain will need to match the address of the Internal VoIP Server configured in the EasySBC configuration page:

Note: if a fully qualified domain name (FQDN) is used rather than an IP address then the name will need to resolve in DNS. You can check this by going on to a PC and typing PING <fqdn>


Outcome 3: CDR appears with both IN and OUT records

If you can see both an IN and OUT CDR for the call then the call has been successfully presented to your SIP trunk provider BUT the call has failed.

If you see a 403 Error in the CDR entry this error has been caused by an authentication failure:

SIP Registration: If your provider requires SIP registration then please verify that the     EasySBC is registered with the SIP trunk provider.  Click here for details on how to verify SIP registration.

IP Authentication: If your provider doesn't use SIP registration then you are most likely using IP authentication, where the IP address of the SIP packets leaving your network have to be from the IP address you have given to your SIP trunk provider.

If you see a 404 Error in the CDR entry there is a problem with the number being sent to the provider.  The number will either be in the wrong format or is a number that doesn't exist. Check the number by calling from another known working phone to verify the number works. If that works then verify the format of the number being sent to the provider, this can be seen in the Call record.


For other Error codes please check here.


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