Hammerhead Systems Inc. thinks it's got a good spin on the whole Provider Backbone Transport (PBT) thing, acting as a gateway between PBT and the IP/MPLS world.

It's a software feature that Hammerhead introduced today. (See Hammerhead Works PBT.) The reasoning seems straightforward. Hammerhead's HSX 6000 aggregation box can already move various traffic types to an MPLS core, so why not add PBT to the list?

"To us, it's a modest software addition," says Rob Keil, Hammerhead's vice president of marketing. "What we're responding to is increased interest in PBT."

The features comes at the behest of the one Tier 1 customer that Hammerhead is willing to hint about. Hammerhead isn't revealing the name, of course, but industry talk a year ago pointed to the MCI piece of Verizon Communications Inc. (NYSE: VZ). (See Has Hammerhead Nailed Verizon?)

BT Group plc (NYSE: BT; London: BTA) has made the most prominent commitment to PBT. (See Nortel, Siemens Win PBT Deals at BT.) Others reportedly are studying the technology. One Tier 1 carrier is rumored to be preparing a request for proposals (RFP) that includes PBT, a move that's drawn interest from Hammerhead partner Fujitsu Network Communications Inc. (See Will Fujitsu Join PBT Parade?)

It's likely some will create "islands" of PBT in an otherwise MPLS-based network, Keil says. A carrier already using the HSX 6000 for MPLS traffic, then, could use the new software option to plug a PBT island into the box as well, he says.

"Operators are looking for devices that would not eat up as many of those expensive router ports," says Stan Hubbard, an analyst with Heavy Reading. "The idea is that you have these hybrid networks where you have the option of adding PBT into the metro."

The most logical competitor to Hammerhead's gateway idea would be Cisco Systems Inc. (Nasdaq: CSCO), which has the right software pieces to turn a router into this kind of PBT gateway. But Keil says he doesn't expect Cisco to jump in here.

"PBT's promise is to reduce the complexity of IP. It's a threat to any router vendor, in that it could commoditize routers," Keil says.

Cisco, for its part, says it isn't rejecting PBT; rather, its customers are still questioning the technology and aren't willing to commit yet. "We are keeping an eye on this and listening to our customers about PBT. But we're hearing a lot of questions right now," says Mike Capuano, a Cisco senior marketing manager.

— Craig Matsumoto, West Coast Editor, Light Reading