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

[Livio Zanol Puppim]

Neus 2000 does not have FCoE.

2010/2/9 Manu Chao <linux.yahoo at gmail.com>

> 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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>
>


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Lívio Zanol Puppim