[c-nsp] Nexus 2000 vs Catalyst 4948 for access layer

[Manu Chao]

Two key advantages:
- Technical: FCoE, vPC
- Management: you needn't to manage N2Ks

R/
Manu

On Tue, Feb 9, 2010 at 11:40 AM, Livio Zanol Puppim <
livio.zanol.puppim at gmail.com> wrote:

> Yeah, You are right.
>
> But I would like to use my nexus 5000 10GE/FCoE ports just for access
> servers, maximizing it's use... The uplinks from Nexus 2000 could easially
> go directly to my distribution/core. Unfortunally, nexus 2000 is just an
> fabric extender and can ONLY be attached to Nexus 5000... Maybe CISCO
> changes it's later...
>
> Let's think:
>
> 10 nexus 2000 using all uplink ports = 40 ports. Yes, 40 ports that I must
> use at my nexus 5000. That's more than 1 entirelly switch (1RU) and almost
> 1
> switch (2RU).
>
> I haven't figure out yet what's the advantage of having this design (nexus
> 2000 -> nexus 5000) other than the "old" one (catalyst 4948 -> nexus
> 7000/cisco 6500). That's what I'm talking about.
>
> The only REAL advantage so far is the vPC...
>
> 2010/2/2 Brad Hedlund <brhedlun at cisco.com>
>
> >
> > True, the Nexus 2000 does not locally switch, but lets explore that for a
> > second...
> >
> > 1) a typical enterprise Data Center is running applications that are not
> > latency sensitive, where latencies in the 10s of microseconds are
> perfectly
> > OK and nobody is really counting anyway. Only in the small minority of
> Data
> > Centers running high frequency trading, grid computing, or some other
> ultra
> > low latency application, every *nanosecond* matters and local switching
> with
> > fewer hops is of paramount importance. Furthermore, these applications
> are
> > quickly migrating away from 1GE to 10GE attached servers for the obvious
> low
> > latency advantages.
> >
> > 2) the Nexus 2000 has 4x10GE uplink bandwidth versus the 2x10GE uplink
> for
> > 4948.  This results in a possible 1:1.2 oversubscription ratio for Nexus
> > 2000 to handle the additional uplink load that may otherwise not be
> present
> > on a 4948.
> >
> > 3) The upstream Nexus 5000 implements cut-through switching, and the
> Nexus
> > 2000 itself also uses cut-through for frames entering on 1GE and
> egressing
> > on 10GE.  The two combined often results in port-to-port latencies
> similar
> > to a Catalyst 6500, even without the "local switching".  If you are
> > comfortable with your Catalyst 6500 local switching latencies, you can
> > expect similar performance from a Nexus 2000/5000 combination.
> >
> >
> > --
> > Brad Hedlund, CCIE #5530
> > Consulting Systems Engineer, Data Center
> > bhedlund at cisco.com
> > http://www.internetworkexpert.org
> >
> >
> >
> > On Jan 31, 2010, at 5:25 PM, David Hughes wrote:
> >
> > >
> > > On 29/01/2010, at 6:54 AM, Livio Zanol Puppim wrote:
> > >
> > >> Can anyone please tell me the advantages of using Nexus 2000 over
> > Catalyst
> > >> 4948 as access layers switches?
> > >> Using Nexus 2000, I have to use at least 2 ports at my Nexus 5000,
> that
> > >> could be used by servers with 10GbE/FCoE servers.
> > >
> > > The N2K does no local switching so if you have any east-west traffic
> > between ports on the same switch you'll be better served by a more
> > "traditional" access switch.  Naturally the N2K offers centralised
> > management etc etc but that may or may not be of interest depending on
> the
> > size of your deployment.
> > >
> > >
> > >
> > > David
> > > ...
> > > _______________________________________________
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> >
> >
>
>
> --
> []'s
>
> Lívio Zanol Puppim
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