In order to get 56k you have to have PRI or T1 channelized.. I just assumed
that since you did not have PRI then the area was remote and you also did
not have channelized T1.. but if you do then all you need is the ISPorte
with 56k modems, digital adapters and the T1 adapter.
What I think the are talking about with the PPTP tunneling is that you
would actually reroute the ISDN call to another box...
I have the 6100's and they have both ISDN and 56k.. the Cisco 2511
determines if it is a ISDN or 56k and below and the establishes a VPN or
PPTP with the modems.. and they can be in the same chassis or they can be
in another chassis....
Sorry if I confused the issue!!