As the folks at Hammerhead Systems briefed me on their new system for interworking PBT and MPLS, a spokesperson pointed out that it addresses two of the biggest criticisms of PBT so far from entrenched MPLS router vendors: namely, that it’s a just point-to-point technology, and it can’t handle multicasting.

Hammerhead’s gear, which uses control plane software from Soapstone Networks, is designed to allow multicasting, point-to-multipoint and multipoint-to-multipoint PBT networks. So what, the spokesperson asked, will those router vendors say now?

I don’t imagine PBT’s critics will wave any white flags this week.

For starters, they might reiterate the argument that a multipoint PBT network doesn’t really eliminate the complexity of an MPLS network (PBT’s chief selling point); it just sweeps that complexity into the control plane. Soapstone Networks, the control plane provider, will argue that it isolates and hides that complexity from the network operator, keeping the user controls simple. (“You just use it,” Soapstone’s Larry Dennison told me once. “It’s black magic.”) And the other side will ask which major carriers will be willing to trust their crucial provisioning and management functions to this start-up’s mysterious black magic. And so on.

Journalists are naturally inclined to gravitate toward these types of debates. And sure, Juniper Networks CEO Scott Kriens probably helped fuel the perception of this as a religious argument when he called PBT potentially “catastrophic.” But PBT and MPLS suppliers are not quite Hatfields and McCoys. Nortel, the first PBT torchbearer, has said that the two technologies are complementary. (In fact, one of the first U.S. telcos to deploy PBT, Frontier, also uses Juniper’s MPLS routers in its backbone.) And some MPLS vendors have conceded that if their customers start demanding PBT, they’ll find a way to satisfy that demand.

Hammerhead and Soapstone are helping PBT compete with MPLS more effectively for metro networks. But they are also helping to foster an environment in which PBT and MPLS can more easily coexist. So it will be interesting to see to what extent MPLS router vendors are in support of that.

E-mail me at ed.gubbins@penton.com.