LOS ANGELES -- OFC/NFOEC 2011 -- The recently announced PTX from Juniper Networks Inc. (NYSE: JNPR) turns out to have a behind-the-scenes helper: an OEM'ed version of the FSP 3000 from ADVA Optical Networking .

Juniper calls it the OTS1000, and it's been on display at OFC/NFOEC all week.

The OTS acts as the optical shelf for one or more PTXs. It's where the DWDM transponders for the PTX could reside, for instance, if a carrier opts to not use IP-over-DWDM. The OTS would also house things like ROADMs or add/drop multiplexers -- in other words, everything the FSP 3000 does.

So, it plays a key role in what Juniper calls the converged supercore, the conceptual unit that also includes the PTX and Juniper's T-series core routers. (See Juniper Makes Its Packet-Optical Move.)

The OTS wasn't mentioned at all in last week's PTX launch. Juniper will sell and support the box, but only as a companion to the PTX. Juniper will never sell the OTS by itself, says Luc Ceuppens, Juniper's senior director of marketing. (Makes sense; they'd basically be doing ADVA's job, which might strain that relationship a little.)

One key element of the OTS is that it's running Junos and uses the same management system as the PTX. Juniper's software treats the OTS and PTX as one unit.

They probably won't ever be physically integrated, Ceuppens says. The boxes have fundamentally different backplanes. The PTX uses an active backplane because it's likely that some traffic will hop from one blade to another. Optical systems don't do that, so the OTS has a passive backplane.

— Craig Matsumoto, West Coast Editor, Light Reading