Bandwidth priorities per call cost

Hello all !

First of all, thank you for this efficient software.

Here is the thing that I want to do. I got a given bandwidth, and 2 clients, and a fixed cost for the calls.

The first client usually does not use the whole available bandwidth, but should always be able to call through asterisk.

The second client will then use the remaining bandwidth.

Basically here is what I want to do.

Could you point me some hints, and where to look in asterisk to do that ? If it is not an implemented feature ?

Thanks a lot in advance for your answers.