[Users] Is this configuration possible?

I'm trying to build Openser with these requirements. Sorry, for the newbie questions. I have 10 users and a PSTN gateway. Let's say each users makes a call for 10 minutes. Is it possible to just show 100 minutes being charged on the PSTN gateway instead of 10 seperate users? If that is possible. Would I need the B2BUA in asterisk to accomplish this? I read Asterisk at large. I was wondering besides using Asterisk for voicemail, what other functions are used with integrating asterisk and openser? __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com