I've gone to work for a business that has around 150 networked end users.
There is a FAC for everyone-and it's my option on whether or not to have them. It takes about twenty seconds after entering an authorization code to dial, and it has become a huge hassle.
What is the main purpose of this functionality? To be able to track when and where phone calls went out? Any time anyone tries to dial long distance, it requires the FAC. I will be consulting with the President of this company today in regards to the phone systems, and up to this point, I've had some successes. I definitely want to be well informed on this issue, and have read all of Cisco's documentation, just need some clarification!
It's a basic method to make sure only people that should be able to make a certain kind of calls (LD/international) is able to do so.
You set a level on their FAC and a minimum level in the route patterns.
A user needs to match or exceed the level from the route pattern to make the call.
ie, you FAC has auth level 10, CEO has auth level 40.
Your international RP has 30. You can't call, your CEO can.
The whole explanation is here.
Introducing Forced Authorization Codes
FACs/CMCs (both explained in above link) are also subject to interdigit timeout caused by overlapping, from what you mention that is what's happening. Read below:
Avoiding Overlap of Extension Dialing
There cannot be overlapping strings of different length. For example, a system with extensions 1000 and 10000 would force users to wait for the interdigit timeout when they dial 1000.
Tell users to press # after FAC or change the dial plan to avoid above situation.
EDIT: you can also change the T_302 timer to lower the interdigit timeout but ideally you shouldn't have any overlapping.
If this helps, please rate