LANCOM Support Knowledgebase Document No. 1906.1813.5335.MMÜL - V1.20

Modifying the “connected number” in ISDN for outgoing calls

In scenarios where an ISDN PBX or an ISDN telephone is operated at a LANCOM router with the Voice Call Manager, a CONNECT signal informs the ISDN device that a telephone call has been established. This message includes the number of the call destination, which is often used by the ISDN device as the “called number”.

In some cases it may be necessary to modify the “connected number”, for example by removing the country code for national calls.

This article describes how to modify the “connected number” with the use of the call-routing table.

The "connected number" can be modified, but it cannot be suppressed completely.

  • LANCOM router with the Voice Call Manager enabled
  • SIP trunk


The call route to be modified has to be the final one that is processed. This changes not only the "connected number” displayed by the ISDN device, but also the dialed number that is transmitted to the provider.

1) In LANconfig, open the configuration dialog for the router and switch to the menu item Voice Call Manager -> Call router -> Call routing.

2) Changing the “connected number” only make sense for local and national calls. In these cases, the country code can be removed.
  • National call: If necessary, replace the Dest. ID entry +49# (e.g. for Germany) with 0#.
  • City area call: If necessary, replace the Dest. ID entry +492405# (e.g. for Germany) with 02405#.

You must ensure that the provider is still able to route the number for outgoing calls. For example, the country code 0049 can be removed from the “connected number” 0049240567890, so that only 0240567890 is displayed. The “connected number” cannot be modified so that only the number 240567890 is displayed.

Catchwords: Connected Number; call routing table
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