Carrier Ethernet technology Provider BackboneTransport (PBT) is back in the news as its leading vendor supporter, Nortel Networks Ltd. (NYSE/Toronto: NT - message board), announces two new, but small, customer engagements and adds test vendor Ixia (Nasdaq: XXIA - message board) to its Ethernet-focused Ecosystem.

    PBT, also known as PBB-TE (Provider Backbone Bridging - Traffic Engineering) in the Institute of Electrical and Electronics Engineers Inc. (IEEE) standards process, has emerged during the past 12 to 18 months as one of the most controversial carrier technologies on the block, mostly because of its reputation as a rival to MPLS in metro network transport deployments. Support for the technology from BT Group plc (NYSE: BT - message board; London: BTA) has raised its profile considerably. (See PBT: New Kid on the Metro Block, BT Pressures Vendors Over PBT, Nortel, Siemens Win PBT Deals at BT, and BT Sells PBT-Based Backhaul Service.)

    But BT isn't the only service provider to have embraced the SDH-like Ethernet technology, as service providers in North America and China are also putting PBT to work. (See Nortel Wins Dakota PBT Contract, Frontier Deploys Nortel PBT, and Nortel's PBT Debuts in China.)

    And now Nortel has two more PBT deals to talk about, albeit very small ones.

    In Australia, Silk telecom , a metro Ethernet services player with its own fiber network in Adelaide and Melbourne, is deploying Nortel's 8600 Ethernet switches in its core and aggregation POPs and the vendor's 1850 Ethernet Services Unit box at the edge of the network in a deal valued at about $1 million. (See Silk Telecom Uses PBT.)

    In India, Mumbai International Airport, the company that manages the city's Chhatrapati Shivaji International Airport, plans to deploy PBT as part of the new communications services network it is building. It is sourcing optical gear, Ethernet switches, and unified IP communications systems from the Canadian vendor. (See Mumbai Airport Uses PBT.)

    At the same time, support for Nortel's Carrier Ethernet Ecosystem, created to build support for PBT and help tackle issues such as interoperability, is growing, with Ixia becoming the first test equipment vendor to sign up. (See Ixia Joins Nortel Ecosystem and Nortel Pushes PBT Pact.)

    Ixia ha sbeen pushing its PBT test capability credentials in the past few months, and is battling with key rival Spirent Communications plc (NYSE: SPM - message board; London: SPT) to attract the attention of the growing number of vendors that are developing PBT products and, therefore, need appropriate lab test equipment. (See Ixia Digs on Wireless, PBT , Mixed Fortunes for Test Vendors, PBT Parties On, Ixia Tests PBT, NSN Touts PBT, PBT Stars at Ethernet Expo , Avici Abandons Routing, Targets PBT, and Huawei Joins PBT Fan Club.)

    While not everyone in the market believes there's a future for PBT, it's clear the technology is attracting increasing interest, and, according to Heavy Reading analyst and Ethernet specialist Stan Hubbard, there are signs that major carriers other than BT are scoping out PBT's capabilities. (See AlcaLu: PBT Is Peripheral and Verizon Preps God Box RFP.)

    Commenting on the record sales of carrier Ethernet equipment reported during the second quarter of this year, Hubbard tells Light Reading that PBT and its close relation, Provider Backbone Bridging (PBB), are "popping up in more RFPs/RFIs, and we understand multiple operators beyond those announced by Nortel are exploring hybrid network solutions." (See CESR Sales Hit All-Time High.)