Outbound Trunking

Outbound trunking is a Registration feature that allows you to present the CLI of another number on your account, using a trunking number. Outbound trunking relieves phone administrators of the onerous task of individually registering large blocks of numbers to preserve CLI.

Setup Outbound trunking

A Caller ID is made of a combination of a ‘From‘ and secondly ‘Contact‘ or SIP URI. By manipulating the FROM you can set an outgoing CLI, whilst using the trunking number Contact to make the outgoing call. The Outbound trunking example below will present 61240009009 as the outbound CLI while using 61240009000 as the registered trunk number:

From: ”61240009009” sip:61240009000@

SIP Peering: One advantage of SIP Peering over Registration is that we honor any account phone numbers (presented via the primary trunk DID).

  1. Log into your account.
  2. Select Switchboard.
  3. Select your number.
  4. Outbound.
  5. Outbound Trunking.
  6. Click Enable outbound trunking on the line you wish to configure as the accounts Outbound Trunk DID.

Please restrict the Inbound trunking with its own password.

Other Notes

  • Display name: Most devices such as softphones and IP Phones refer to the name part as the Display name.
  • Asterisk-based PBX systems the name part can be set in the SIP or IAX2 configuration with the caller id= field – or if you wish to present it in the dial plan when you use the CALLER ID (name) variable. By changing this name partly to the number you wish to present on the call you can achieve multiple caller ID presentations for each DDI over a single registration or login.
  • P-Asserted-Identity: see also a P-Asserted-Identity header (RFC 3325) to define the Caller ID as an alternative to manipulating the name field (subject to your system support for RFC 3325).
  • Groups: Ensure that all FROM numbers are within the same ‘Group’ as the Outbound trunk number.
Updated on 9 December 2021

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