[cisco-voip] AAR vs. Route Lists

[Kelemen Zoltan]

Hi,

this may be a noob question to some of you, but there's something I 
don't quite understand:
 don't Route Lists provide the same (or rather - similar) functionality 
as AAR? If not (and I suppose not) what's the difference?

Case in point:
  We have a client with three CCM clusters, all connected through ICTs. 
We haven't used AAR so far, but the calls are routed through Route 
Lists: the trunk is the first route group, but if that fails, calls are 
redirected to the PSTN route group with appropriate transform masks for 
called and calling numbers.

If the IP trunk is congested, shouldn't the calls be rerouted to the 
PSTN anyway? (even though AAR is not set)

thanks,
  Zoltan