Hi,
if you have been assigned more than one public telephone number on your incoming ISDN line ( on ISDN you will get usually a block of MSN numbers on one line ) you tend to assign these MSN numbers to individual extensions on your UC320W PBX for DID (to reach directly the extension by dialing the associated MSN for this extension)
Example:
You have been given these 5 public phone numbers on your ISDN line:
089 7737730
089 7737731
089 7737732
089 7737733
089 7737734
On the "inbound calls" tab you can configure the associations ( or call routing ) for incoming calls based on the number dialed.
E.g.
089 7737730 routes to extension 30
089 7737731 routes to estension 31
089 7737732 routes to extension 32
089 7737733 routes to extension 33
089 7737734 routes to extension 34
In the other direction for outgoing calls, if extension 32 places a outside call you want to have MSN 089 7737732 signalled as calling id to the recipient (and not the main line numer of your ISDN line), i.e. for extension 32 placing outside calls the Calling ID should be 0897737732.
You configure this on the same config tab "inbound calls"
Just click on the field "use xxxx as Calling ID". For outgoing calls this number will be used now as Calling ID and not the default line number of the trunk configuration.
(The incoming route does not have to be an actual route, i.e. a route which is really used. You could configure 017112345678 as incoming route to extension 32. You would never receive a call on the UC320W when somebody dials
017112345678 since it might be the number of your home or mobile phone.
However, if you place a call from extension 32, it will signal 017112345678 as calling id. Keep in mind that the service provider now needs to allow user define CLIP (CLIP no screening).