How to assign an extension to a channel on a Rhino FXS bank?

General Help
1

Using a Rhino FXS channel bank, how do I go about assigning which
extension goes to which channel on the bank? And how easy is it to
switch them around? x.

Thank you

2

Assuming the T1 is your only DAHDI card it would simply be addressed 1-24

3

I am planning on having 4 channel banks here. Plus one T1 card for voice communication.

Thanks