Routers in Data Centers

Steven King sking at
Sat Sep 25 07:11:25 UTC 2010

 Cisco uses their own ASICS is their higher end flag ship devices.
Devices such as the Catalyst 6500 series or the 2960 switches. You
pretty much singled out all the major players, including those who have
been bought out (Foundry by HP) and claimed they do not provide their
own, yet 3rd party flawed ASICS. I am actually surprised you didn't
mention HP, Linksys or Dell as they are the most guilty of using 3rd
party ASICS and shotty software. If you are buying data center grade
equipment from these vendors, it will be quality hardware backed by
their support (if purchased) such as Cisco's SmartNet agreements.

Moral of the story, do your research on the devices you plan to
implement and ask for data sheets on how the features you need are
handled (in software or hardware). I know Juniper and Cisco provide such
documentation for their devices. Quality hardware, however more
expensive, will give you less trouble in the long run. You truly get
what you pay for in the networking industry.

On 9/24/10 9:28 PM, Richard A Steenbergen wrote:
> On Fri, Sep 24, 2010 at 03:52:22PM +0530, Venkatesh Sriram wrote:
>> Hi,
>> Can somebody educate me on (or pass some pointers) what differentiates
>> a router operating and optimized for data centers versus, say a router
>> work in the metro ethernet space? What is it thats required for
>> routers operating in data centers? High throughput, what else?
> A "datacenter router" is a box which falls into a particular market 
> segment, characterized by extremely low cost, low latency, and high 
> density ethernet-centric boxes, at the expense of "advanced" features 
> typically found in more traditional routers. For example, these boxes 
> tend to lack any support for non-ethernet interfaces, MPLS, advanced 
> VLAN tag manipulation, advanced packet filters, and many have limited 
> FIB sizes. These days it also tends to mean you'll be getting a box with 
> only (or mostly) SFP+ interfaces, which are cheaper and easier to do 
> high density 10GE with, but at the expense of "long reach" optic 
> availability.
> A "metro ethernet" box also implies a particular market segment, 
> typically a smaller box (1-2U) that has certain advanced features which 
> are typically not found in other "small" boxes. Specifically, you're 
> likely to see advanced VLAN tag manipulation and stacking capabilities, 
> MPLS support for doing pseudowire/vpn PE termination, etc, that you 
> might normally only expect to see on a large carrier-class router.
> Also, an interesting side-effect of the quest for high density 10GE at 
> low prices is that modern datacenter routers are largely built on third 
> party "commodity" silicon rather than the traditional in-house ASIC 
> designs. Many of the major router vendors (Cisco, Juniper, Foundry, 
> Force10, etc) are currently producing "datacenter routers" which are 
> actually just their software (or worse, someone else's software with a 
> little search and replace action on a few strings) wrapped around third 
> party ASICs (EZchip, Marvell, Broadcom, Fulcrum, etc). These boxes can 
> definitely offer some excellent price/performance numbers, but one 
> unfortunate side effect is that many (actually, most) of these chips 
> have not been fully baked by the years of experience the more 
> traditional router vendors have developed. Many of them have some very 
> VERY serious design flaws, causing everything from preventing them from 
> fully implementing some of the features you would normally except from a 
> quality rouer (multi-label stack MPLS, routed vlan interface counters, 
> proper control-plane DoS filter/policing capabilities, etc), or worse 
> (in some cases, much, much worse). YYMV, but the 30 second summary is 
> that many vendors consider "datacenter" users and/or use cases to be 
> unsophisticated, and they're hoping you won't notice or care about some 
> of these serious design flaws, just the price per port. Depending on 
> your application, that may or may not be true. :)

Steve King

Senior Linux Engineer - Advance Internet, Inc.
Cisco Certified Network Associate
CompTIA Linux+ Certified Professional
CompTIA A+ Certified Professional

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