[nsp] ATM switching on a 7200

[Robert E. Seastrom]

"Bob Collie" <bob at ena.com> writes:

> Agreed; however you can do Frame Relay switching on the 7200 as well as
> FR-ATM and vice versa Internetworking at the packet level, so why can't
> you do ATM switching?

Because Frame Relay can be thought of as just being a studlier verson
of HDLC/PPP (or a stripped down X.25 depending on whether you're a
glass-half-empty or glass-half-full type) and is handled completely in
software.  ATM, on the other hand, is viewed by the router through a
SAR (segmentation and reassembly) chip.  All of the ATM-ish stuff is
handled by the SAR; the router CPU never sees the ATM cells, just
reassembled packets.

Hope this helps,

                                        ---Rob