[c-nsp] Nexus 7000

[mack]

This is disappointing :(
The sales hype indicated this was revolutionary.
Instead it is a slight improvement over the existing switch gear with crippled MPLS and routing capability.
The 4:1 over subscription at the port level even limits it for intense SAN usage.

--
LR Mack McBride
Network Administrator
Alpha Red, Inc.


> -----Original Message-----
> From: Tim Stevenson [mailto:tstevens at cisco.com]
> Sent: Tuesday, January 29, 2008 7:12 AM
> To: mack; Tom Storey; Pete Templin
> Cc: cisco-nsp at puck.nether.net
> Subject: RE: [c-nsp] Nexus 7000
>
> At 03:04 AM 1/29/2008 -0600, mack observed:
> >Ok that math doesn't make sense.
> >60/48=1 1/3 not 2.
>
> So at small packets, this system can do 4 ports non blocking & 6704 can
> do ~3.
>
> >Even at that 32 ports with 80gbps forwarding is still an
> >oversubscription of 4:1
>
> Yes, this card is 4:1 oversubscribed at the port level - ie 4 ports
> share 10G b/w toward the rest of the system, you will never get more
> than 10G from each 4-port group.
>
>
> >Of course real world will probably allow forwarding of more than
> >80gbps at 60mpps.
>
> You will not get more than 80G out of this card.
>
>
> >The performance listed jives pretty well with the 230gbps / slot
> >(figure 500 byte packets).
>
> The 230G is a characteristic of the intially shipping FABRIC - the
> initially shipping IO modules don't leverage the full fabric b/w.
>
> >Meaning a 1.4:1 oversubscription on the 32 x 10GE card (assuming
> >single direction traffic).
>
> No, you will not get a 1.4:1 ratio on this card.
>
> Tim
>
>
> >--
> >LR Mack McBride
> >Network Administrator
> >Alpha Red, Inc.
> >
> >