help • 8 Trunks  • Forwarding and number substitution • Defining call number substitutions for a trunk group
8.7.1 Defining call number substitutions for a trunk group
For individual phone numbers or SIP URIs, you can define a special, automatic phone number substitution. You can create number substitutions for
*outgoing caller numbers,
*outgoing Target numbers,
*incoming Caller numbers and
*incoming destination numbers
Example:
Original number +4923112345 is replaced by 12345
If using a profile that has the setting "national" for the destination number, then without this entry 023112345 would be dialed. However, certain special phone codes can be reached only with 12345, and not with a prefixed local area code.
* 
Numbers that are to reach the public telephone network must be entered in canonical format.
 
You can also use placeholders when defining rules, see 15.5 Placeholder.
"Apply also in reverse" option
If you activate the option Also apply in reverse option, this replacement applies in both directions, i.e. the incoming caller number is replaced and vice versa the outgoing destination number, as well as the incoming destination number and the outgoing caller number.
Replacement configured for
"Apply in reverse" affects
Outgoing caller number
Incoming destination number
Outgoing destination number
Incoming caller number
Incoming caller number
Outgoing destination number
Incoming destination number
Outgoing caller number
Example:
Original number +44* is replaced by 0044*
If "Also apply in reverse" is activated, then for incoming calls the 0044 in the caller number is replaced by +44.
To set a call number substitution
1 In the menu, select Connections | Trunks.
2 Select Trunk groups.
3 A list appears with all Trunk Groups.
4 In the row of the desired trunk group, click .
5 Select in the menu Trunk group name | Forwarding & Replacement.
*The tab Forwarding entries.
6 Select the desired tabs
*Outgoing caller number
*Outgoing destination number
*Incoming caller number
*Incoming destination number
7 Click Add phone number replacement.
*The configuration wizard appears Add phone number replacement.
8 Define the replacement for a phone number or a SIP URI.
Label
Explanation
Original call number:
Enter the original phone number or URI.
Replacement:
Enter a replacement for the original phone number.
Also apply in reverse
Enable the option to apply the replacement to both directions.
9 Click on OK.
*The phone number replacement is added and appears in the list.
You can adjust or delete the number replacements using the buttons and .