Provider - Custom VoIP

Hello, is there any limit to the amount of Custom VoIP providers that can be created on the system? Our scenario is an AsteriskNOW box situated locally on a network where a number of apartments will use our Internet and VoIP service. They will connect via SIP to the AsteriskNOW PBX and then each “extension” will have it’s own custom VoIP provider created in order to connect to our hosted Enswitch (Asterisk) switch. This will allow the apartments to have a local directory where each client can call the others by their apartment number directly and for free (also preserving WAN bandwidth). Any external outbound and inbound calls will be routed via the Custom VoIP provider trunk per client via the Enswitch. This is where the built in accounting and billing is carried out and inbound DIDs etc are managed. Initially we expect 30-40 subscribers growing to over 100 over the next few months. Regards, Phil.

it looks like that your extension is not a real extension. it is a sip trunk for your down level asterisk.
so from 40 extension to 100 extension means from 40 concurrent calls to 100 concurrent calls.

Asterisk can do this, but you need to be careful.