LANCOM Support Knowledgebase Dokument-Nr. 1901.2513.1903.MMÜL - V1.10

Sending the calling number for call forwarding over a SIP trunk

This document describes how to send the calling number instead of the called number when forwarding a call over a SIP trunk.

By default, the calling number is replaced by the called number. This means that the called party is unable to identify the original caller and cannot call back.

  • Configured and functional SIP trunk
  • Configured and functional call forwarding (under Voice Call Manager -> Users -> Extensions)
  • Any web browser for access to the web interface (WEBconfig)


This configuration cannot be done in LANconfig, but only via WEBconfig or the command line.

1) Connect to WEBconfig and log in with root privileges.

2) Navigate to the path LCOS menu tree -> Setup -> Voice Call Manager -> Users -> Extensions.

3) Click on the Name and, in the following menu, use the drop-down menu to set the item CF-Set-Cln-Id to the value Calling-ID.

4) Confirm the configuration by clicking on Send.
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