PBT's promoters shift gears as market stalls

The latest sign of unfulfilled expectations for the once-hot Provider Backbone Transport (PBT) sector came this week as the first vendor to develop a PBT control plane reported trouble finding traction.

Soapstone Networks announced a 10% reduction in its workforce this week to adjust for what it called an unexpected delay in the development of a market for PBT, also called Provider Backbone Bridging – Traffic Engineering (PBB-TE) by industry standards groups.

“The PBT market didn’t develop as we expected it was going to,” said Bill Stuart, Soapstone’s chief financial officer, while the company reported fourth-quarter earnings Thursday.

Though the original drivers for the technology remain, as does interest in it, the market for PBT has been “delayed,” said Chief Executive Officer Bill Leighton, as technological pieces are still missing that would allow PBT, originally developed as a point-to-point technology, to handle multicast and local area network services.

“Those technical aspects are being addressed over time, and we expect to see continued interest in the technology,” Leighton said.

Soapstone’s control plane software was designed to help PBT take such evolutionary steps past its point-to-point roots. Nortel announced E-Tree multicasting functions for its own PBT gear in late 2007 and the development of its own PBT control plane last year.

After Nortel Networks proselytized PBT in 2006 as a simpler alternative to MPLS in metro networks – a connection-oriented Layer-two-type technology that uses tunnels of reserved bandwidth in transport networks – a cadre of other vendors announced their own support for PBT, including Extreme Networks, Hammerhead Networks, Fujitsu Network Communications, Ciena, Anda Networks and chip vendor Lightstorm Networks. Some of them entered into marketing agreements with Nortel to promote the nascent technology, and some also partnered with Soapstone.

But demand for PBT cooled significantly last year, according to multiple sources, leading many of PBT’s promoters to dial down their discussion of it. (Some blamed a shift away from PBT and toward MPLS by UK carrier BT, which helped Nortel develop PBT.) Even Nortel began to talk more about PBB, an existing superset of PBT technology not connection-oriented in nature.

In a recent interview with Telephony, Hammerhead Networks -- one of the first to follow Nortel’s lead with a gateway to interwork PBT and MPLS networks -- claimed to have sold that product to unnamable tier-one and tier-two carriers alike and that interest in it continues. But a company spokesperson was eager to avoid being pigeon-holed by PBT.