The CDC abilities -- especially the contentionless part -- come about by having both the Cyan and Calient optical elements present. Wavelength-selective switches (WSSs) are outfitted on the Cyan Z77 boxes, so they can act as reconfigurable optical add/drop multiplexers (ROADMs), working in conjunction with Calient's S320 photonic switches.
By having one management system run the Calient and Cyan boxes, the companies say their optical network can avoid contention -- that is, they can avoid having two different flows of traffic trying to use the same wavelength at a given node.
The buildout is for Minnesota Telecom, which received $43.5 million in American Recovery and Reinvestment Act (ARRA) money; about half of it was in the form of a grant, the other half a loan. The telco, a subsidiary of Minnesota's Northeast Service Cooperative, has built out a 915-mile fiber ring with 14 nodes so far, serving 340,000 residents of northeastern Minnesota.
That's way the heck out there, so Minnesota Telecom was determined to do as much remote monitoring and provisioning as possible. Having a contention-free network was a big requirement.
"They're extremely sharp, technologically, and they really drove the network vision themselves," says Daniel Tardent, Calient's director of product line management.
Why this matters
There might be some contention (pun possibly intended, but we won't admit it) about that claim of being a CDC "first." Some networks achieve contentionlessness by limiting the possible network configurations. But they don't avoid contention by applying network intelligence.
Besides, contentionless ROADMs didn't really exist until recently. Past deployments are at least one "C" short, in other words.
A multilayer control plane, combining packet and optical views, is a key to the whole deployment. Calient and Cyan are still working on it, but the end result will be that Calient's S320s will be run by Cyan's CyMS management software. CyMS is built to manage multiple layers at once in Cyan's own gear. The company has extended that capacity to a few Ethernet vendors and is now reaching out in the optical direction as well.
Cyan is one of the few vendors actively working to create multivendor control planes. Its progress with Calient on that front might be more important than the CDC stuff.
A bit more on Cyan and Calient, with an eye towards Service Provider Information Technology (SPIT):
- Cyan Widens Its Ethernet View
- Cyan Aiming High With Management Play
- Calient Gets Ambitious With Optical Switching
— Craig Matsumoto, Managing Editor, Light Reading