Rethinking the Network

Marten Terpstra

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Top Stories by Marten Terpstra

A while ago I wrote a few articles describing the various tunnel protocols used for network virtualization between vSwitches on servers, and between vSwitches and physical network gateways. These are the mechanisms that construct overlay networks on top of a physical network. VMWare uses STT as the tunneling mechanism between vSwitches on servers and VXLAN to communicate with gateways to the non virtualized world. NVGRE is used mostly by Microsoft, and is an extension to GRE tunneling that has been around for a while. Each one of these mechanisms have their pros and cons. They are all pretty much standard, or at least published by a standards organization, and multiple implementations exist of most of them. Outside of my complaint about the stream like nature of STT, the biggest problem with all of them is the fact that they are fixed in their definition. The head... (more)

The Power of Correlated Visualization by @MartenT1999

I am sure our work environment is not all that different from many others. There are large whiteboards everywhere and you cannot find a meeting room that does not have circles, lines and squares drawn on them. Some of our favorite bloggers have written blogs about network drawing tools and aids. Probably not restricted to just networking folks, but we certainly love to visualize the things we do. Out of all the customers I have visited, the amount of them where one of us did not end up on a whiteboard can probably be counted on one hand. It is not surprising that we are drawn t... (more)

The Network as a Complex Distributed System By @MartenT1999 | @CloudExpo

Through http://blog.ipspace.net I landed on this article on acm.org discussing the complexity of distributed systems. Through some good examples, George Neville-Neil makes it clear that creating and scaling distributed systems is very complex and “any one that tells you it is easy is either drunk or lying, and possibly both”. Networks are of course inherently distributed systems. Most everyone that has managed a good sized network before knows that like the example in the article, minor changes in traffic or connectivity can have huge implications on the overall performance of a... (more)

Traffic Advisory: Your Packets May Be Delayed

The past few years have seen a dramatic improvement in the latency in network switches. Single ASIC based switches can all pretty much switch packets in less than a microsecond. Current 10GE switching silicon provides anywhere from 300 to 800 nanoseconds, specialized silicon shaves that to less than 200 nanoseconds when limiting the amount of searching that needs to be done by reducing the size of lookup tables. Even other solutions play some smart tricks by providing forwarding hints for intermediate switches make those lookups take less than 50 nanoseconds. Modular switches i... (more)

The Silence of The Lambdas

We still see quite a few eyebrows raised when we explain how we use WDM optics in our datacenter solution. In the various descriptions of the Plexxi solution it is often mentioned and referred to, but it is worth explaining what that optical infrastructure actually looks like and why it is part of our solution. One of the key attributes of the Plexxi solution is the ability to create network topologies at L1, L2 and L3 that meet the need of the workload offered, calculated based on the load on the network, and the Affinities created that describe the needs of specific applicatio... (more)