Typically you won't have all your users calling at the same time
So there are some guidelines when calculating concurrent calls
You have some user types
Heavy Users: 1 line required for every 5 users
Medium Users: 1 line required for every 10 users
Light Users: 1 line required for every 15 users
So normally you have 1 call for every 10 users (but that may vary)
You should plan for 10 E1 connections
A mediation server can cope with 200 simutaneous connections (todays hardware may perform even better)
If you require multiple mediation servers then you also need multiple Gateways (Gateway & Mediation server is a one to one connection)
- Belgian Unified Communications Community : http://www.pro-exchange.be -