Google's Move to Software-Defined Networking | Hacker News Reader

Google's Move to Software-Defined Networking

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51 pointsalanfranzoni6 comments

"Basically, what I think Google and some other companies find attractive about SDN is the ability to affect policy more directly from a single location with one view of the network as a whole."

That's "Software defined networking", which is a lot like virtual circuits. The first time A tries to send to B, a request is sent to some central server which decides if A can talk to B, how A gets to reach B, and whether it's desirable to listen in or MITM the conversation. The central server then sets up the routing, but doesn't handle the traffic.

This is amazingly like Tymnet, circa 1969.

Amazon has something like this internally, which they use as a big patchboard for their servers. This gives them freedom in allocating IP addresses. It's am example of "There is no problem in computer science which cannot be solved by adding another layer of indirection."

Or more specifically in networking "another layer of encapsulation".

https://en.m.wikipedia.org/wiki/Virtual_Extensible_LAN

The logical end case for VXLANs: https://en.wikipedia.org/wiki/Distributed_Overlay_Virtual_Et...

Everything old is new again :-) I read through the SDN specs and thought "Hmm, this reads like they are trying to implement ATM, badly." But one of the really fun things is that nearly all of the switching fabric patents from DEC/Tandem/Etc. from the 90's are evaporating and so we can actually build something like ATM now without getting bogged down in that mess. Because of that I'm pretty optimistic that it will make things a bit better than they were.

Indeed. While I am not a fan of everyone "doing SDN", I did enjoy this article. It seems that Google are doing interesting stuff, in so far as rejecting legacy protocols where practical (i.e their private WAN) and building something better, which hopefully will eventually seep into common knowledge and usage.

Except this is actually working pretty well as opposed to ATM :)

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