Chassis Free Campus Networking for Lower Total Cost of Ownership

As a continuation to my previous blog post “Rethink the Campus: No Chassis Required for Future-Proof Networking”, I wanted to dig deeper to quantify the difference between chassis based architecture and the fixed port based architecture, to support the low price point claim. For a true comparison, we need to look at the total cost of ownership (TCO). TCO is the combination of capital costs (one-time infrastructure expenses) and operating costs (ongoing maintenance and support expenses). To keep it simple let’s look at one time purchase price and power requirements for these architectures.

A typical large campus deployment something like a community college campus or a large hospital would require about 3000 edge ports with support for power over existing network cabling infrastructure (PoE+) and multicast-enabled full streaming audio and video applications for converged services, such as Voice over IP (VoIP), WLAN access points, IP surveillance cameras, and other IP technology devices.

imageWith the new PowerConnect 8100 campus aggregation/ core switch product line and PowerConnect 7024 edge switches a large campus network can be built. This network comprises of 32 stacks of 4 units of PowerConnect 7024P switches each with 24 ports. These stacks can be located in an IDF. The number of stacks and units in stack can be changed. The edge switches are connected to a collapsed core of PowerConnect 8164s located in a MDF. With 2:1 oversubscription in the collapsed core, this architecture enables 3072 edge ports capable of supporting Voice over IP (VoIP) phones hat require low latency and high Quality of Service (QoS) at all times. These technologies place a tremendous strain on the campus LAN network, requiring multiple GbE uplinks to the aggregation layer and onward to the core switches.

When I compared this to couple of chassis based solution from Cisco and HP that require two 10-12 RU chassis to be deployed with same amount of edge port stacks to preserve the oversubscription; the numbers were overwhelmingly in favor of the PowerConnect 8100 based architecture. The fixed port aggregation/ core not only meets all the requirements for design including high-availability, high performance and density but also provides significant CapEx and OpEx savings.  

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The obvious comeback to this argument is that Cisco does have fixed port aggregation options with 4500-X platform. Even when you plug-in the numbers for 4500-X, the total cost for Cisco solution only changes only by $100K to $1.1M and the power requirements change by 4KW to 37KW. Compared with a fixed port option from Cisco, Dell’s solution has much better TCO even when lifetime warranty on the Dell’s product is not part of the equation.

Overall, there are some use cases and deployment scenarios where chassis based architecture is required with features like redundant supervisor modules but there is a compelling case for fixed port 10GbE based solution in a streamlined campus network.

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1 List prices used in calculations are obtained either from the vendor or authorized distributors. Variation in pricing should be expected and may impact TCO.

2 Power requirements used in calculations are obtained from individual product data sheets supplied by the vendor.