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Rethinking the Network

Marten Terpstra

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Top Stories by Marten Terpstra

I don't read nearly as much as I should. On plane rides I tend to grab a Vince Flynn, James Patterson or David Baldacci, they are usually enough to entertain me on the way there and back. One of the more interesting books I have read in recent years that does not include murderers, spies and explosions, is "Brainrules" by John Medina. A rather good leadership seminar at my previous employer had this on its reading list, and I tore through it. John Medina is a molecular biologist and in his book he describes how our brain works by breaking it down into several areas, each describing a major function of the brain, coupled with some suggestions on how to improve or impact that function after understanding how it works. There are many fascinating facts and studies in the book, but two specific items stuck with me. One, the brain is incapable of multitasking. We all love ... (more)

Managing Tables in Our New Virtual Reality

In traditional networks, MAC addresses are inserted into tables using standard learning techniques.  When packets arrive, if the source MAC address is not known, it is added to the MAC forwarding table for that VLAN with the ingress interface as its destination. If the destination is unknown, the packet is flooded through the VLAN, with the side effect that each switch along the way inserts the source MAC address in its own forwarding table for that VLAN. Assuming the destination actually exists, one of the flooded copies will reach its destination. The device at the destination ... (more)

Many Waze to Cambridge

I work mostly in Plexxi’s office in Nashua, NH. That is about a 12-minute commute for me, backroads only through two sleepy towns. Very convenient and a great improvement over my previous commute. Every now and again I make the trek out to our Cambridge office and it is painful. About 40 miles and around 45 minutes of mostly highway on a good day; early morning this is easily a 90-minute exercise, and finding myself on the road for two hours is not unusual. I am not very attached to a GPS, but whenever I travel a distance or know I am going to hit traffic, I turn on Waze on my p... (more)

OpenFlow Evolution: Standardized Packet Processing Abstraction Is Hard

With the Open Network Summit 2014 about to start in Santa Clara next week, I realized I had not done much OpenFlow reading recently. It is no secret that Plexxi does not use OpenFlow as the API between our switches and controller due to restrictions in what OpenFlow can do (or in some cases could do when we needed to make architecture and design choices). When I saw the ONS announcement I thought it an opportune moment to sync myself to the latest and greatest in OpenFlow world. What started out as a mechanism to program flows into network switches and routers in a standard way ... (more)

Network Services, Abstracted and Consumable

Perhaps not as popular as its brothers and sisters I, P and S, Network-As-A-Service or NaaS has slowly started to appear in industry press, articles and presentations. While sometimes associated with a hypervisor based overlay solution, its definition is not very clear, which is not at all surprising. Our industry does not do too well in defining new terms. I ran across this presentation from Usenix 2012 that details a NaaS solution that adds a software forwarding engine to switches and routers that provide specific services for some well known cloud computing workloads. I have ... (more)