# Introduction

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@192.168.178.164:5060 SIP/2.0*

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

Solution:

- 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.

Solution:

- 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.