I adopted a 5 site, frame relay WAN, that was undersubscribed at the main location. All WAN links and the main are at 1.5M. No math degree required to figure out that the cumulative bandwidth between remote sites and main will get congested. Right now, we are very close. If two branch locations have a busy day, it directly impacts all branches.
This is a hub/spoke configuration with Voice, Data and Management in each location and call management centralized.
My frame relay provider gave several options to aleviate the problem, one being a full ATM connection in the main location with the remote DLCIs pointed to the ATM at the main location. I am really looking for some feedback as to whether this is a solid solution, and How does the router configuration in the main location change from it's frame-relay config. Also, documentation and references would help.