Multiple presentation numbers on 1 isdn 30

Not sure if this belongs here but I’m hoping someone can answer my query because I’m getting conflicting information from everyone involved.

We have a call server running asterix, and an ISDN 30 from BT, is it possible for individual groups to dial out over the isdn 30 using different presentation numbers, so that different businesses within the same office can have separate numbers?

In case you have multiple DIDs from your ISDN-30 provider you could set the callerid of the outside call accordingly to those DIDs.

Basically you have to put Callerid(num)=DID-X for calls initiated by Group X. Of course, each provider have its own rules on how they accept the callerid information from their clients and this is why you have to ask them how many digits you have to put there (the whole DID, last 3 numbers, etc).