Cyan Inc. and Calient Technologies Inc.
are partners on what they say is the first truly colorless,
directionless and contentionless (CDC) optical deployment -- a bit of a
milestone for optical networking, if true.
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
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):
— Craig Matsumoto, Managing Editor, Light Reading