Are there any guidelines for determining how many phone lines to order? Let's say we have 80 users. Right now, we have 80 analog phone lines. In a VoIP world, to match that, I'd need to order 4 T1s if I want to be able to support everyone on the phone at once.
But in a typical office environment, not everyone is on the phone at once. Are there any formulas/guidelines telco's use to help size how many phone lines you should order?
I realize of course it all depends on the profile of your users. Call centers might need 100% capacity. But in a standard office, I'm guessing more like 60%? Anybody have any examples they've used?