Here we explain the Inbound DID settings that will enable you to match the incoming DID number with the internal extension number.

Inbound DID's

Here you can specify how the incoming dialled number is changed so that only the internal extension number remains.

Example: Last 3 Digits are the internal numbers

Invite message from the provider looks like this: Request-Line: INVITE sip:999205998@ SIP/2.0

999205998 is the number that is dialled and extension 998 should receive the above call.


  • Remove the not used digits, 999205(\d)
  • The remaining digits will be defined as variable $1

In this example it will mean that the last 3 digits are used to match to the internal number. When an user/group/IVR/.. has the number 998, it will get the incoming call.

Destination: Last 3 numbers (DDI) match the internal numbers

You also need to use the following setting for the inbound routes:

^(.*) = Every incoming number range

$1 = The variable that is in this example every DDI that is dialled.

Destination: All numbers are routed to one number

All numbers needs to be forwarded to an fixed internal number.


Destination DDI 997 is routed to fixed number

DDI 997 has to be routed to extension 200, Do not to forget to add also option 1 that all other DDI's are directed to the internal numbers.


Example: Last 3 Digits are internal numbers but the in a different number range.

Like in the example above, the internal number range is not 900-999 but 800-899. We need to change the incoming DDI number.


  • Remove the not used digits, 9992059(\d)
  • The remaining digits will be defined as variable $1 but we add the additional 8

For every incoming DDI the 9xx will be changed to 8xx.





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