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Re: Where are ATM NAPs going?

  • From: Stephen Sprunk
  • Date: Tue Dec 19 17:10:59 2000

Thus spake "David Charlap" <[email protected]>
> Leo Bicknell wrote:
> >
> > Regardless of how good the technologies are, the router vendors
> > have killed ATM as a future nap technology.  To use the Cisco
> > example, ATM tops out an OC-12 ...

I thought there weren't commonly available SAR chips for OC48 yet.

> > If there were OC-48 or OC-192 ATM coming, and/or switches
> > with the density to make that work it would have a future, but alas,
> > that seems to not be in any vendors road map.
> My company (Marconi) makes such a switch:

Push as many bits/RU as a typical GE switch and you can reapply for the
term "density".

Claimed Bandwidth: 40Gbit/s
Height: 32 RU
BW per RU: 1.25Gbit/s
Volume: 14.59 cu.ft.
BW per cu.ft.: 2.74Gbit/s

Cat6500 (typical GE switch):
Claimed Bandwidth: 256Gbit/s
Height: 14.4RU
BW per RU: 17.78Gbit/s
Volume: 4.54 cu.ft.
BW per cu.ft.: 56.39Gbit/s

I assume other vendors' GE/POS products have a similar density edge over
ATM; I was just using the most expedient example.

> Non-blocking OC-48c ATM interfaces have been shipping for some
> time now.

Switching/trunking ATM at OC48/OC192 speeds is relatively trivial.
Doing SAR, even on perfectly ordered cells, at those speeds is
non-trivial.  Packet slicing sucks.

> -- David


     |          |         Stephen Sprunk, K5SSS, CCIE #3723
    :|:        :|:        Network Design Consultant, GSOLE
   :|||:      :|||:       New office: RCDN2 in Richardson, TX
.:|||||||:..:|||||||:.    Email: [email protected]