Add and Edit Trunk

Trunks are added to allow callers to dial out. The easiest way of dealing with adding trunks is to create the trunk in the asterisk dial plan, and test it there first before testing with A2billing. This simply removes a level of complexity when debugging a trunk.

VoIP Provider

Select the provider from the provider list already entered.


Give the trunk a sensible name so you can identify it later.

Add Prefix

Add digits from the beginning of the dial string

Remove Prefix

Remove digits from the trunk.

Provider Technology

The type of technology being used to deliver the call, valid parameters may be:-

  • SIP
  • IAX2
  • ZAP
  • H323
  • local -used to dial numbers in the local dial plan

Provider IP

It is simplest to put in the context name or name of the trunk that you created within Asterisk. Make sure it is spelt exactly the same, it is case sensitive.

However, you can put in the URL or IP address, if the carrier only needs a very simple authentication.

Additional Parameters

Rarely used, this is to allow the delivery of extra parameters in the trunk. Variables or tags can be used such as: -

  • %dialingnumber%
  • %cardnumber%

i.e. 'D(ww%cardnumber%wwwwwwwwww%dialingnumber%)'

Failover Trunk

A failover trunk can be defined, but note that the same cost and rate applied to the customer will be applied as for the original trunk.


Submit your changes. The trunk will be active immediately.