[nsp] Re: Catalyst 6500 Hybrid

[sthaug at nethelp.no]

> In one corner: Cisco 12000 and basically all the Junipers and in 
> some aspect perhaps the 7300. Real routers, real hardware LPM routing, 
> deep packet buffers.
> 
> In the other corner, L2/L3 switches, more or less hardware enhanced
> routing, most of the time small packet buffers. Here I'd place the
> 6500/7600 (even though the OSM cards complicate things). Juniper has
> nothing here. On the other hand, Extreme and Foundry does.
> 
> A couple of years ago the argument was pretty easy to do, the switches
> just didn't do proper routing. With the Sup720, Extremes BD10k, Foundry
> has something (I dont know about them) that'll do real routing. They still 
> lack deep packet buffers.

I don't see how the Sup720 is more of a "real" router than Sup2, with
the possible exception of the TCAM size (enabling uRPF with current
Internet routing tables). The Sup2/MSFC2/PFC2 still do longest prefix
match like any other router.

> I have talked to vendors about the size of buffers. Seems everybody is 
> making the argument that deep packet buffers costs HUGE amount of money. 
> Even putting 80ms instead of 5ms (no to even mention the 600ms buffers on 
> the real routers) is a big price hike.

Interesting that you should mention buffer sizes. On the end2end-interest
there is now an argument going, part of which is that you probably do
*not* want as deep buffers today as you previously did. However, 80ms
would still be nice to have!

> Now, if we're talking just about the Cisco 7600 versus the 12000:
> 
> Ok, I want a chassi, 4 10GE ports and 10 1GE ports. If I go with the 7600 
> LAN cards I can do this for less than $100k. If I go with the 12000 I'd 
> have a hard time doing it for less than $500k. Doing it with 7600 OSM 
> cards puts it somewhere in the middle.

I'm used to the 7600 OSM cards in connection with MPLS (you need them to
do MPLS with Sup2). We found to our great surprise that the OSMs cannot
handle ACLs (and it's even documented, if you know where to look). That
means the OSMs are lacking one significant feature - do I want to pay
extra to get deeper buffers if that means I can't have my ACLs?

> I like the 12000 and Junipers, these are real routers and they're 
> appropriate core tools, but THEY ARE TOO EXPENSIVE. I'd rather build two 
> cores and know I'd never overload it, than to build a single core that'll 
> handle occasional overload properly.

Agreed that 12000 and Junipers are expensive - the basic impression is
that any kind of equipment that can handle hardware based forwarding 
for non-Ethernet media is outrageously expensive. I don't see this
changing any time soon :-(

Steinar Haug, Nethelp consulting, sthaug at nethelp.no