[nsp] Architecture question

[sthaug at nethelp.no]

> I see references littered throughout the internet to the CzBus
> architecture.  Are there any good documents on this?

None that I know of. However, I don't see the Czbus as all that relevant
today.

> Is the 3600, 3700, 7600, & 2600 series routers architectures
> documented anywhere?  In detail like the IOS book?  Are they CyBus,
> CzBus?

2600, 3600 and 3700 are traditional "one processor does all the work"
routers. Yes, they are modular - but the NM / WIC / VIC cards are all
passive in the sense that they don't make any forwarding descisions.

7600 is really a 6500 in disguise. This is a rather complex box,
with one of the most important characteristics being that almost all
packet handling is done in hardware. This includes normal IP routing/
forwarding, policy routing, and also for instance access lists. The
7600 *can* be distributed (line cards with independent forwarding
using a DFCx, e.g. the 6816 16-port GigE card), and it can also be
centralized (forwarding decisions done by the PFCx).

Steinar Haug, Nethelp consulting, sthaug at nethelp.no