Software-defined networking (SDN) is often described as a way of programming the network. Wouldn't it make sense, then, for someone to offer a compiler for the network?

That's what startup Contrail Systems wants to do, as executives explained to Light Reading this week.

Contrail, based in Santa Clara, Calif., is notable because it's packed with veterans of the big networking vendors, particularly Juniper Networks Inc.. It's the company that lured Multiprotocol Label Switching (MPLS) expert Kireeti Kompella away from there. (See Juniper Veteran Departs for SDN Startup.)

The compiler approach, which Kompella noted in a talk at the recent MPLS World Congress in Washington, D.C., isn't the only way to do SDN. But for the customers that want the network to be simplified as much as possible -- and Contrail is betting there are a lot of them -- the compiler approach could do the trick. "You tell us what you want to have happen, not how," he says.

In computer programming, a compiler translates a high-level language -- one where the code uses familiar human words -- into executable instructions. Contrail is saying its software, still not commercially released, does the analogous thing to the network.

Kompella describes it this way: You'd tell Contrail's software how the network should look, who can talk to whom, or which services (like load balancing) traffic should go through. The software would program the switches, routers and/or appliances accordingly, using OpenFlow or ordinary routing protocols or whatever other means it can.

The key, and the real promise of SDN, is to operate on the network as a single organism, rather than having to tweak things at the systems level, he says.

— Craig Matsumoto, Managing Editor, Light Reading