[c-nsp] Cisco CRS-1

[Richard A Steenbergen]

On Sun, Jul 16, 2006 at 07:41:44PM +0200, Gunther Stammwitz wrote:
>  
> > As opposed to all of those other routers and switches out 
> > there which do more than 40Gbps per slot today?
> 
> Foundry can do 40 gig per slot or even 100 gig per slot. Check out their
> netiron mlx series.

Ok, you people have all lost your minds. A lot of folks replied to me 
private too, saying "but the Foundry XMR/MLX can do 100 gigs per slot!". 
Don't get me wrong the XMR/MLX (and RX which is almost the same thing) are 
actually ok boxes, but they are not magical.

Rather than having typical slots that are "chassis-wide", the new Foundry 
boxes split the box down the middle and make their slots "half-width". The 
individual cards connect to the central fabric via cell-switching over 
multiple parallel links, and stripe data to fabric elemenets on switch 
fabric cards (3 per), giving each slot 48Gbps of cell switching capacity. 
Of course, once the data gets onto the card itself, there are still only 
two 20G links to 20G packet processor ASICs which handle groups of 2x10GE 
or 20/24xGE just like everybody else. There is nothing revolutionary here, 
Foundry doesn't have access to "special" technology that other people 
don't have.

The theory behind the half-slots is that some day in the future when there 
is technology to implement 100GE, they'll be able to make a card that is 
"chassis-wide" (aka takes 2 slots next to each other) and have 96Gbps of 
cell switching capability into the fabric (minus whatever the overhead 
is on it). This is the same kind of theory that went into the BigIron's 
with the 8Gbps per slot capacity being "10GE ready" in 1999, which is 
actually a decent comparison because we're about as far away from 100GE 
today as we were from 10GE then. Of course look at the reality of the 
situation, in the 5 years between new technology came out and now buying a 
10GE port for a BigIron is one of the silliest investments you can make.

But as always, the devil is really in the software not the hardware. I'll 
reserve judgement on the new platforms and new software for heavy duty L3 
use since I haven't tested it, but you can really never go wrong by saying 
"sure fine the hardware moves bits, but what about the software?".

-- 
Richard A Steenbergen <ras at e-gerbil.net>       http://www.e-gerbil.net/ras
GPG Key ID: 0xF8B12CBC (7535 7F59 8204 ED1F CC1C 53AF 4C41 5ECA F8B1 2CBC)