Example of HFO SIP trunk gateway group settings.

Outbound caller ID

As just the last digit of the trunk number block is changing, you can select just the last digit (in brackets) and put it into the variable $1. As the provider wants the signalling number in the format (city-code)(number), you have to enter this number into the next line (here: 0891234567$1, where the $1 represents the changing part).

For external calls, we will present e.g. 08912345678 to the calling provider, and he will take care about the correct representation to the called party.

Asserted Identity

These fields are used specially for external forwardings. Some providers need special settings in order to present the correct number at the receiving party. For HFO Telekom, you can forward the number as it is with ^(.*) and $1copy the entries from the Outbound caller ID fields. Here: \d\d(\d) and 0891234567$1 (new screenshot will follow).

Inbound DIDs

For incoming calls, you can use the regular expression, generated by the setup assistant. In your case you would have to adjust the city-code and the pilot-number, according to your line-settings.

^(?:(?:(?:0049|\+49|49|0)?89)?12345)?(.*)

This expression cuts all possibly available country- and city-codes and the pilot-number from the incoming number and only the extension is remaining (here: 678). This will be forwarded to the Inbound Routes.

Inbound caller ID

For incoming calls, we will add an additional 0 in front of the external number of the caller, in order to use the callback-feature of the phone (e.g. 0089987654321). During the call-setup the additional 0 will be automatically removed.

Gateways

This field will be empty when you create this Gateway group. It will show later the assigned SIP gateways.