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Brad Hedlund is a Systems Engineer at Cisco Systems in the U.S. Enterprise Sales Organization and is the editor of Internetwork Expert.ORG. Brad has 12 years experience in Enterprise IT networking and has been CCIE certified for 8 years - CCIE #5530 (Routing and Switching). In August 2007, Brad received recognition as a "Top Engineer" at Cisco.

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Cisco Nexus 5000 announced Today

April 8th, 2008 • Related • Filed Under
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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.

One thing for sure is that this is a great time to be at Cisco and a great time to be a Cisco data center customer!

 

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There Are 6 Responses So Far. »

  1. Comment by Omar Sultan on 8 April 2008:

    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. Comment by Brad Hedlund on 8 April 2008:

    Thanks Omar.

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

  3. Comment by Kai on 25 April 2008:

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

  4. Comment by Brad Hedlund on 27 April 2008:

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

  5. Comment by Kai on 29 April 2008:

    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. Comment by Brad Hedlund on 24 May 2008:

    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.

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