Router-switch-router "peering module"

["Howard C. Berkowitz" <hcb () gettcomm com>]

I'm hunting for some presentations or papers on what I've seen called 
a "peering module", using a router, a L2 switch, and a router in 
series, rather than a single router. Unfortunately, I can't remember 
where I saw the detailed description, and I haven't been able to find 
it in the NANOG archives.

IIRC, the rationale was to spread filtering and rate limiting over a 
set of processors, also to keep the configuations more manageable.

Does anyone have any pointers to detail?  I've seen the topology, but 
not a detailed discussion, in a couple of Cisco presentations.