A simple design requirement that I'm having trouble finding a useful solution to... Hopefully I'm merely overlooking something obvious...
Background:
Two dial-in servers using local authentication with about 100 lines each (ISDN PRI to 3640s).
Spokes using ISDN backup with all calls placed by spokes using a single BRI interface and no dial back.
Just enough lines for 1 b-channel per spoke if all spokes require ISDN backup at the same time (think disaster scenarios).
The Goal:
Under normal conditions, only a few to a few dozen spokes will need ISDN, so the desire is to use MLPPP for maximum possible bandwidth. The challenge is that as the number of spokes requiring ISDN exceeds 50% we need a way to force all spokes to limit themselves to a single B-channel without manual intervention or additional hardware.
Acceptable Alternative (if "the Goal" can't be met):
First "X" spokes to dial in get MLPPP, any additional spokes which call in get limited to a single channel (note that this requires provisioning extra PRIs to handle X 2-B-channel calls under worst case conditions).
Further Constraints:
Manual intervention is not acceptable--operation is 24x7 but staffing is only 8x5.
Local authentication is strongly preferred. Adding RADIUS or TACACS servers would have a major cost impact.
Dial-in servers also support other classes of callers and dial-out connections, so dialer profiles must be used, which eliminates BAP/BACP.
Single points of failure are not acceptable, nor are solutions which the TAC could not support (I don't want to be a single point of failure either :-).
Thanks in advance for any ideas which lead to a cost effective solution.
Vincent C Jones
www.networkingunlimited.com
