Nortel Networks has yet another IP router play and this time it thinks it has a winner.

The Multiservice Provider Edge (MPE) 9000 platform -- codenamed "Neptune" -- is what Nortel calls a next-generation IP/MPLS service-converged edge system as opposed to a router or a switch retrofitted to collapse Layer 2/3 services for transport over an MPLS core.

MPE 9000 IP routing and frame/ATM switching from Nortel's older Shasta IP services and Passport multi-service switches, respectively. It is Nortel's most recent attempt to re-engage itself in IP after several missteps.

MPE 9000 features two models, scalable from 2.5G bit/sec to 80G bit/sec, targeted primarily at services such as IP/VPNs, Internet access, Layer 2 circuits over MPLS (Virtual Pseudo-Wire), any-media Layer 2 interworking, virtual private LAN and broadband aggregation. The MPE 9200 is targeted at small and mid-sized central offices and offers 20G bit/sec of switching capacity in 5U of rack height. The MPE 9500 is designed for medium to large central offices. It provides 40G or 80G bit/sec of throughput in 14U of rack space.

Sounds like another multi-service router or switch, right? Nortel is very careful not to classify the MPE 9000 as either/or.

"We're not going after the router or switch business" with the MPE 9000, says Sue Spradley, president of Nortel's Wireline Networks business unit. "This is a new category of device designed to go after the edge where services converge."

"What's different is Nortel's existing expertise in QoS and reliability," says Mark Bieberich, an analyst at The Yankee Group. The MPE 9000 "was designed from the ground up to address consolidation. That's a differentiator to others retrofitted to consolidate."

Some of Neptune's features include:

-- A "flexible and scalable triad" (FAST) midplane hardware architecture that uses programmable processors to provide a fully meshed interconnection topology separating control and data plane traffic, and enabling mixing and matching of card types for sparing. MPE's Multiprocessor Control Plane enables scale at the card and processor level via field installable Control Plane Extender modules.

-- A "secure autonomous fault-tolerant environment" (SAFE) software architecture enabling hitless software upgrades, rollback, and patching to reduce scheduled and unscheduled downtime. Nortel says SAFE is a partitioned and protected software architecture featuring "independent" software processes designed to prevent "leaked" routes, fairly allocate processing and memory resources, and isolate faults and recover from failures via a redundant hot-standby process or process restart.

-- A Linux-based "services routing operating system" featuring weighted-fair-queuing and scheduling of CPU and memory resources.

Some of Nortel's competitors, including Cisco Systems, Juniper Networks and Alcatel, already have these features in their multiservice switches and routers, in whole or in part. Neptune will have more company in June when Lucent Technologies is expected to ship Phase 1 of its 35G bit/sec CBX 3500 multiservice switch.

Like Neptune, the CBX 3500 is expected to feature a midplane architecture with distributed mesh switching that enables incremental capacity upgrades, sources say. The midplane separates the frontside I/O adapters (IOA) from the backside I/O switching modules (IOM). Two central slots in the 16-slot 3500 chassis are reserved for active and standby switch processors.

Each IOM features a 2.5G bit/sec independent switch fabric that enables service providers to incrementally add capacity as needed, the sources say. This is different from the previous generation CBX 500, which required the 622M bit/sec IOMs to connect to the central switch processors to access the switch fabric.

On the software side, the 3500 will feature a "non service impacting upgrades" capability that limits outages to less that 50ms for protected ATM circuits, sources say. This capability is not expected until the Phase 2 release of the switch in October, however.

The 3500 will also support a modular routing blade, developed by Juniper and analogous to the routing vendor's M71 or M10i platforms, to perform MPLS Label Edge Router functions for services such as IP-enabled Frame and RFC 2547 VPNs, the sources say. This capability is expected to be previewed at Supercomm in June.

Lucent was not immediately available for comment.

As for the MPE 9000, the product will ship in the fourth quarter. Service providers Equant NV, Infonet Services Corp. and Telus Corp. are currently putting the system through trials and it is also currently undergoing interoperability testing with Avici Systems Inc.'s TSR core router in Nortel labs in Ottawa.

Meanwhile, the future of Nortel's Shasta and Passport switches for the edge are secure ... for now. Spradley says the MPE 9000 will "complement" those products initially but become the "vehicle of choice" down the road.