From the Last Bastion of Mainframe Computing Perspectives post:

The networking equipment world looks just like mainframe computing ecosystem did 40 years ago. A small number of players produce vertically integrated solutions where the ASICs (the central processing unit responsible for high speed data packet switching), the hardware design, the hardware manufacture, and the entire software stack are stack are single sourced and vertically integrated. Just as you couldn’t run IBM MVS on a Burrows computer, you can’t run Cisco IOS on Juniper equipment. When networking gear is purchased, it’s packaged as a single sourced, vertically integrated stack. In contrast, in the commodity server world, starting at the most basic component, CPUs are multi-sourced. We can get CPUs from AMD and Intel. Compatible servers built from either Intel or AMD CPUs are available from HP, Dell, IBM, SGI, ZT Systems, Silicon Mechanics, and many others. Any of these servers can support both proprietary and open source operating systems. The commodity server world is open and multi-sourced at every layer in the stack.

Last week the Open Network Summit was hosted at Stanford University. This conference focused on Software Defined Networks in general and Openflow specifically. Software defined networking separates out the router control plane responsible for what is in the routing table from the data plane that makes network packet routing decisions on the basis of what is actually in the routing table. Historically, both operations have been implemented monolithically in each router. SDN, separates these functions allowing networking equipment to compete in how efficiently they route packets on the basis of instructions from a separate SDN control plane.

In the words of OpenFlow founder Nick Mckeown, Software Defined Networks (SDN), will: 1) empower network owners/operators, 2) increase the pace of network innovation, 3) diversify the supply chain, and 4) build a robust foundation for future networking innovation.

This conference was a bit of a coming of age for software defined networking for a couple of reasons. First, an excellent measure of relevance is who showed up to speak at the conference. From academia, attendees included Scott Shenker (Berkeley), Nick McKeown (Stanford), and Jennifer Rexford (Princeton). From industry most major networking companies were represented by senior attendees including Dave Ward (Juniper), Dave Meyer (Cisco), Ken Duda (Arista), Mallik Tatipamula (Ericsson), Geng Lin (Dell), Samrat Ganguly (NEC), and Charles Clark (HP). And some of the speakers from major networking user companies included: Stephen Stuart (Google), Albert Greenberg (Microsoft), Stuart Elby (Verizon), Rainer Weidmann (Deutsche Telekom), and Igor Gashinsky (Yahoo!). The full speaker list is up at:

The second data point in support of SDN really coming of age was Dave Meyer, Cisco Distinguished Engineer, saying during his talk that Cisco was “doing Openflow”. I’ve always joked that Cisco would rather go bankrupt than support Openflow so this one definitely caught my interest. Since I wasn’t in attendance myself during Dave’s talk I checked in with him personally. He corrected that it wasn’t a product announcement. They have Openflow running on Cisco gear but “no product plans have been announced at this time”. Still exciting progress and hat’s off for Cisco for taking the first step. Good to see.

If you want a good summary of what is Software Defined Networking, perhaps the best description were the slides that Nick presented at the conference:

If you are interested in what Cisco’s Dave Meyer presented at the summit, I’ve posted his slides here:

Other related postings I’ve made:

· Datacenter Networks are in my Way

· Stanford Clean Slate CTO Summit

· Changes in Networking Systems

· Software Load Balancing Using Software Defined Networking

Congratulations to the Stanford team for hosting a great conference and in helping to drive software defined networking from a great academic idea to what is rapidly becoming a supported option industry-wide.


James Hamilton



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