Juniper Networks Inc. (NYSE: JNPR) is joining the packet-optical transport systems (P-OTS) ranks, proposing an architecture that stands out for its emphasis on Multiprotocol Label Switching (MPLS).

Juniper's PTX Series Packet Transport Switch, scheduled to launch Thursday, adopts the philosophy of using MPLS for handling packet traffic and Optical Transport Network (OTN) for circuit traffic. That's in contrast to the OTN focus of other packet-optical products on offer from vendors such as Alcatel-Lucent (NYSE: ALU) and Ciena Corp. (NYSE: CIEN).

"We're saying LSPs [label switched paths] rather than OTN, because we believe LSPs are the future," says Luc Ceuppens, Juniper's senior director of marketing. That packet-based approach is more suited towards the bursty, unpredictable patters of future network traffic, Juniper believes.

The PTX is starting life as an MPLS switch -- what used to be called a Label Switch Router (LSR). As a core box it's a Layer 2 alternative to expensive core-router ports, a concept that Verizon Communications Inc. (NYSE: VZ) has been championing at optical conferences for a couple of years.

Did we mention the PTX is big? Based on a new chipset called Junos Express, the PTX can support 480 Gbit/s per slot. An eight-slot version will be available in July, and a 16-slot version should follow six to 12 months later. Later on, Juniper plans to introduce a multichassis version of the PTX, with arrangements that can handle a claimed 3,800 Tbit/s of total traffic.

Why this matters
As P-OTS has grown in importance, with even Cisco Systems Inc. (Nasdaq: CSCO) announcing a box, the pressure has been on Juniper -- a company with no optical heritage -- to come up with something. And Juniper has decided to make its entrance big, producing a core P-OTS system to compete with AlcaLu's 1870 Transport Tera Switch and Ciena's 5400.

But not right away. Key elements still aren't there: Reconfigurable Optical Add/Drop Multiplexer (ROADM) support will come in 2012 and OTN switching in 2013, says Heavy Reading analyst Sterling Perrin.

"It looks like everybody has the same endgame in mind. They're just coming at it from different strengths in terms of what comes out first," Perrin says. Huawei Technologies Co. Ltd. , for instance, took the opposite tactic, starting with a big optical box that could add packet handling later.

Ceuppens claims the "majority" of Juniper's customers have not asked for OTN. Perrin, on the other hand, points out that practically every telco still has circuit-switched traffic that OTN was designed to support. It's going to be tough marketing to telcos without OTN, he notes.

Cable operators, though, would be more willing to go with an all-packet core. Maybe that's where Juniper's real initial targets for the PTX will have to be.

For more
Here's what's transpired with Juniper and optical networking in the past year or so.

And here's the skinny on core P-OTS.

— Craig Matsumoto, West Coast Editor, Light Reading