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Brad Hedlund is a Consulting Systems Engineer at Cisco Systems focused on Data Center technologies with 13 years combined experience as a Cisco customer, Cisco Partner, and now as a Cisco employee. While at Cisco, Brad has been awarded: "Top Engineer" (August 2007), "Systems Engineer Sales Champion" (August 2008), "SE Excellence" (May 2009). Brad Hedlund is CCIE #5530 (Routing & Switching).

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Cisco Nexus 5000 announced Today

What is the new Cisco Nexus 5000? — The industry first switch to deliver unified server I/O, providing Fiber Channel and IP traffic over a single 10G Ethernet port to the server.  Nexus 5000 delivers very low latency wire speed lossless Ethernet service to the server.

Nexus 5020

As you can see from the photo the Nexus 5000 does not have RJ45 ports, rather it utilizes SFP+ which can be populated by a SFP+ twinax copper cable to deliver 10GE copper down to the server.  Why not RJ45 10GBASE-T??  Two major reasons: (Power and Latency)

Power consumed (each end) by 10GBASE-T = ~8W

Power consumed (each end) by SFP+ Coax = ~.1W

Latency of 10GBASE-T = ~2.5us

Latency of SFP+ Coax = ~.25us

You could also use SFP fiber to the server but of course at the disadvantage of cost.  The SFP+ copper cable, on the other hand, is expected to be in the $100 or less range.

This will be the cable you can buy for dowlink connectivity to the server.  As you can see the SFP+ connector is soldered to the coax copper cable from the factory:

What is the downside of this SFP+ twinax copper cable?? — Max Distance = 10m

This means your SFP+ twinax copper will remain within the rack as it does not have the distance to travel throughout the data center.

The Nexus 5000 is therefore a Top of Rack switch.  You will then run fiber from your Nexus 5000 (in the top of the rack) to the 10GE Ethernet aggregation point (Nexus 7000) for traditional IP connectivity.  You will then have fiber from your Nexus 5000 (top of rack) to your SAN fabric (MDS 9500).

What is the impact of this? — Is Top of Rack clearly the way to go now?  Traditionally Cisco has never picked sides in the Top of Rack vs. End/Middle of Row debate in data center infrastructure cabling — we accommodate both implementations very nicely. However given that 10GE server connectivity appears to be going the SFP+ direction, does that mean we will start to encourage customers to give Top of Rack more consideration?

Or, will the large existing installed base of End\Middle-of-Row Cat6 push Cisco to deliver a Nexus 5000/7000 with 10GBASE-T notwithstanding the power and latency issues that come with it??  Only time will tell.

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Related post: Top of Rack vs End of Row Data Center Designs


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There Are 14 Responses So Far. »

  1. Brad:

    We are still not advocating a particular access layer topology. With the launch in January, we maybe 10GbE available for end-of-row, rack, and blade form factors. We also noted that the Nexus will be a family of unified fabric switches. So, while the N5K is the first form factor available that delivers FCoE, its not the last, and in the long run, Cisco customers will still have the freedom to design the access layer that best meets their needs without forgoing any functionality.

    Omar

  2. Thanks Omar.

    FYI to readers: Omar is a Product Marketing Manager at Cisco, responsible for new Data Center technologies such as Nexus.

  3. One question, is it possible to connect the Nexus 5000 series to standard 1Gb switches?

  4. Kai,
    The Ethernet downlinks and uplinks on Nexus 5000 today are 10GbE only.

  5. Thats to bad as this switch would be perfect for converged networking and high performance storage even for just a one rack. Il guess Il have to cross my fingers for a pair off down scaled 5010’s. :)

  6. FYI – In a future version of software the first 15 ports of the Nexus 5000 will be able to support 1GB. The ports ASICs on Nexus 5000 are capable of 1G, its just that the current version of NXOS software is not capable of recognizing a 1GB SFP port yet. The next rev of NXOS that will recognize 1GB SFP+ should be available this year.

  7. Does Nexus 5000 support 3rd party SFP+ Cu cables that are not “cisco” brand?

  8. Will a 3rd party SFP+ Cu cable work? YES! (keep in mind Cisco has currently only certified 5 meter cables, if you buy a longer 3rd party cable than 5 meters you are taking a risk).

    Is a 3rd party SFP+ Cu supported by TAC? Only the Cisco cables are currently (as of 6/5/09) TAC supported.

    Will TAC hang up on you? NO!

    If all troubleshooting options have been exhausted TAC does reserve the right to ask you to replace the 3rd party cable with a Cisco cable to continue the troubleshooting process.

    Cheers,
    Brad

  9. If I use the 5000 Today and put it in my Network. Do I have to disable VNTags?

  10. Please rename your site to CiscoBigots.org

  11. If I use the 5000 Today and put it in my Network. Do I have to disable VNTags?

    No. VNTag capabilities are in hardware waiting to be provisioned. The Nexus 5000 forwards frames with or without VNTags by default.

  12. Please rename your site to CiscoBigots.org

    Note to readers: This juvenile post was made by an employee of Hewlett-Packard.

  13. Nicely done. I would have deleted it or posted his log details. HP marketing gets in contact pretty quickly when this type of thing happens.

  14. @etherealmind I have his name, email, and IP address if anybody questions it. Didn’t think it was necessary to post all that info … but my mind could be changed if he keeps it up.

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