We need to set up ISDN connections from the main office to multiple branches. The main office will have fewer ISDN connections than the number of branches. This is because branches do not need constant connections.
Each branch will be able to dial up, go through a hunt group at the phone company, and connect to the main office router via ISDN.
How can I determine the optimal ratio of ISDN lines at the branches to ISDN lines at the main office?