Juniper Antes Up on Ethernet (Finally)

Pump up the Ethernet
Filling one third of a telecom rack and sporting 12 slots for linecards (plus two for switching cards), the MX960 has a 480-Gbit/s capacity -- that is, it can handle 480 Gigabit Ethernet ports or 48 10-Gbit/s Ethernet ports. The MX960 will launch with two types of linecard: 40 ports of Gigabit Ethernet and four ports of 10-Gbit/s Ethernet.

Those figures appear to give Juniper the lead in raw Ethernet density for this type of box. Alcatel's 7750 has a 400-Gbit/s capacity but in practical terms is limited to 200-Gbit/s throughput -- that is, it can pack a maximum of 200 Gigabit Ethernet lines. The Cisco 7609 can manage 384 Gigabit Ethernet lines.

Juniper's lead could shrink quickly. "What will probably happen in the next six months is, Alcatel will upgrade the 7750 to give it 400 Gbit/s of throughput," Ovum's Seery says. Cisco likewise has a capacity upgrade in the works, Seery believes, although he thinks the 7600 will still end up lagging on the density side.

The MX960 runs on Juniper's JunOS operating system, meaning it's compatible with the M- and T-series routers and will be familiar to carriers.

But that creates a temporary handicap when it comes to operations, administration, and maintenance (OAM), a key element toward making Ethernet "carrier class" and therefore palatable to service providers. The current JunOS version doesn't support connectivity-layer OAM as defined by IEEE standard 802.1ag -- meaning that standard will be absent from the first MX960 release.

Link-layer OAM as defined by IEEE 802.3ah is present in JunOS and is therefore supported in the MX960. Still, companies including Cisco have already announced support for both IEEE standards. (See Ethernet Crew Tackles OAM.)

The MX960 also falls short of Alcatel and Cisco in some subscriber metrics. The two competitors boast the ability to shape traffic per subscriber, a feature lacking in the MX960. And for quality of service, Alcatel and Cisco allow each port's traffic to be sorted into 8,000 queues, compared with eight queues per port for Juniper's new box.

Juniper points out it doesn't intend the MX960 to be used for subscriber management, preferring to keep those functions in its E-series boxes. "If you talk to Alcatel, Alcatel is going to say our platform does not have subscriber management features. Well, it's not meant to," says David Boland, Juniper senior product manager.

The difference is part of the argument over whether subscriber management should be combined with routers or left as a separate function. Seery, for one, thinks Juniper should gravitate towards the former, as Alcatel has done. "That's the direction to go in. Juniper needs to hurry up and pursue subscriber management on the '960," he says.

— Craig Matsumoto, Senior Editor, Light Reading