I have a trunk that in addition to the number with which it logs in also has a series of 100 numbers, in Italian it is called GNR, I don’t know in English …
However I have difficulty in diverting incoming calls using “Inbound Routes” I use the did and indicate the extension but it seems to ignore it … Maybe I have to indicate that I accept anonymous calls or something?
As far as I can tell, Gruppo a Numerazione Ridotta, when combined with Selezione Passante, is what the English language, non-VoIP world, would call a DID (direct in dialling) trunk. In the terminology that seems to be adopted by the SIP world, it is a trunk with a collection of DIDs that happen to have consecutive numbers.