Japanese giant NTT Group (NYSE: NTT) is set to put carrier Ethernet technology PBT (Provider Backbone Transport) to the test in early 2008, according to industry sources, so joining a host of Tier-1 operators intrigued by the technology's proposition. (See PBT: New Kid on the Metro Block and PBT's Ethernet Appeal.)

While NTT has not responded to questions regarding PBT -- a controversial pre-standard, connection-oriented implementation of Ethernet -- sources say the carrier is pulling together a group of vendors with a view to testing PBT's data transport capabilities in March 2008.

Nortel Networks Ltd. , the leading vendor driving force behind PBT, won't say if it's involved with NTT's plans. "We're engaged with a number of the world's leading operators [regarding PBT], but we can't confirm if NTT is one of those," says a spokesman for the Canadian vendor. (See Nortel Pushes More PBT and Nortel Preps New PBT Switch.)

NTT isn't the only major carrier that's more than a little curious about PBT. Largely thanks to BT Group plc (NYSE: BT; London: BTA)'s decision to deploy the technology in the U.K. and overseas, many operators are keen to check out its potential as an alternative to MPLS. (See BT Goes Live With PBT and MPLS: Metro a No-Go?.)

Verizon Communications Inc. (NYSE: VZ) and BCE Inc. (Bell Canada) (NYSE/Toronto: BCE) have previously shown an interest in PBT, while Deutsche Telekom AG (NYSE: DT) is already putting the technology to work in its labs. (See Deutsche Telekom Flirts With PBT and Verizon Preps God Box RFP.)

Now sources say Orange (NYSE: FTE) and Telefónica SA (NYSE: TEF) are also planning or running lab trials, though neither carrier has confirmed as such.

Growing interest from the world's largest operators is driving increasing interest among equipment vendors: The Carrier Ethernet Ecosystem initiative, led by Nortel, now has 22 vendor members, having just named seven new recruits. (See PBT Club Grows.)

It's notable, though, that Nokia Networks , BT's other PBT supplier alongside Nortel, has not signed up. (See Nortel, Siemens Win PBT Deals at BT.)

And there are signs that the interest from vendors and carriers alike is beginning to generate real business.

While Nortel continues to lead the way in striking a number of small PBT-related equipment deals, Tpack A/S , which provides FPGA designs and applications software for multiple technologies -- including PBT and its MPLS equivalent, Transport MPLS (T-MPLS) -- says the interest is shifting from information requests to orders. (See Nortel Lands PBT Wins, Nortel Wins in Colombia, and Nortel Lands More PBT Action.)

In June, Tpack's marketing director Dan Joe Barry noted there was a lot interest in PBT and T-MPLS. (See PBT Parties On.)

Now, he says, "there are actual orders where PBT is involved, and not just people looking for information. People have signed actual contracts, but with options for T-MPLS as well," notes the Tpack man, though he says he can't identify any PBT customers other than Meriton Networks Inc. , which is supporting PBT in its hybrid packet/optical Carrier Ethernet Transport platform. (See Meriton Tackles Ethernet Transport and Meriton Uses Tpack.)

"PBT is attracting more attention, but no one is discounting T-MPLS. Some vendors have made a marketing call, but most don't want to paint themselves into a corner. It's difficult to say right now" if the market will favor one technology over the other, adds Barry.

"I think 2008 will be the year when we will see concrete trends -- it's still an emerging market at the moment," he concludes.

There are certainly some companies that will be hoping the 2008 trend is anti-PBT. The main MPLS router vendors -- Alcatel-Lucent (NYSE: ALU), Cisco Systems Inc. (Nasdaq: CSCO), and Juniper Networks Inc. (NYSE: JNPR) -- have all spoken out against the new flavor of Ethernet, with AlcaLu taking a major swipe at the technology, and questioning the PBT camp's cost efficiency claims, at a recent industry event. (See PBT Cost Claims Questioned, BT Counters PBT Claims, and Vendors Clash Over PBT.)

— Ray Le Maistre, International News Editor, Light Reading