The Trunks feature allows you to forward calls made to an Account to a specified path (IP based forwarding).

Related documentation:

Setup of Trunks in <=2021 and Incoming routing configuration:

DID Ranges:


The trunk may be triggered in two call scenarios:

  1. Call from a DID number to the number registered on the Account device. This is the scenario when a call arrives from a DID number (in the DID Pool section) and the softswitch routes it to the registered account. The web GUI has an option inside Incoming Routing that allows you to forward calls from a DID number to the number selected in the Incoming Routing section of the Account TRUNK/PBX server

  2. When an On-net call (e.g. from Account to Account) arrives on an Account and the system routes it to a specified Trunk 

Use of fields on the Trunks page:

  • Name - desired name of the Trunk. Unique within one Account

  • Description - optional description of the Trunk

  • Routing policy - the hunting order policy applicable for trunk connection. Ordered - from top to bottom, Round-Robin - reorder the list of vendor-connections for every call:

            case of four Trunk-Connections a,b,c,d. the call routing would be as follows:

* 1st call gets a,b,c,d connections tried

* 2nd call gets b,c,d,a connections tried

* 3rd call gets c,d,a,b connections tried

* 4th call gets d,a,b,c connections tried

* 5th call gets a,b,c,d connections tried

            Available starting from 2023 version.

Use of fields on the Trunk Connections page:

  • Basic tab - contains MANDATORY parameters

  • Name - the name of Trunk Connection. Unique within specific Trunk.

  • Destination - the main field on the Trunk Connections page that requires input of the IP address (or hostname) of the system (PBX) calls would be sent to. 

  • Authentication tab - contains OPTIONAL parameters

  • Username/ Password - enter the appropriate information needed for digest authentication (in case your Trunk requires it)

  • Outbound CLD - optional parameter that gives you the ability to convert/translate the outbound CLD into some other number

  • Advanced tab - contains OPTIONAL parameters

  • Capacity - desired number of Concurrent Calls (CC) to be allowed through this Trunk Connection

  • Max CPS - desired number of Calls Per Second (CPS) to be allowed through this Trunk Connection

  • Outbound IP - specify the appropriate IP address from the list of IPs assigned to your environment. Thus, Sippy would route SIP requests to the Trunk via the selected IP. It is useful when your PBX demands an exact IP for the authentication of traffic from Sippy

  • From Domain - changes the IP address in the "From" header field of the INVITE request (made to a PBX/vendor) to specified domain name  

  • Random Call Id - setting that allows outbound call IDs to be randomized. This prevents PBX/vendor from seeing the IP addresses when UAs include them in the call IDs

How to setup a Trunk:

1) Open the Accounts page and press the drop-down "Action" menu (see screenshot below):

2) Select the Trunks sub-menu (marked as 2 on the screenshot)

3) For >=2022 version press "Create" button to create a new Trunk and fill Name with optional Description

4) Multiple Trunk Connections are supported. After creation of the Trunk press button with a pen at the right column:

5) Add/Edit Trunk Connections list by pressing the plus button

6) Fill all needed parameters and press check button to save changes. For basic setup it's enough to fill Name and Destination

7) Extra options of Trunk connection are available under Authentication and Advanced tab

8) It's possible to change order that is used to send call to - e.g. try first Connection C, not Connection A.

In the list of Trunk Connections there is Reorder button: