[nsp] IP over ATM?

[Tony Mucker]

We're currently looking at getting something a little more beefy than 
our current T1. 

Right now, I have two options in front of me, IMA (Inverse Multiplexing 
for ATM) and four bonded T1's (both from different providers).  Either 
option would get me 6 Mbps.

I've got the hardware handy to do 4 T1's, but don't have the module for 
my Cisco routers to do the IMA (NM-4T1-IMA).  I also see that the module 
has been EOL'd by Cisco, with a final sale date of 31MAR04. 

Has anyone had experience with IMA?  Seems like the IMA modules (both 
NM-4T1-IMA and NM-8T1-IMA) were never too popluar.  The monthly cost for 
both options is the same, but with the IMA I'd need to find a module 
somewhere.

Are there any pitfalls?  The 4 T1's would be round-robined, which I 
don't have a problem with.

Thanks for your help.
Tony