On 25th February 2011, the ITU-T Study Group 15 determined a Recommendation that defines Y.1731 based operations, administration and management (OAM) for MPLS transport networks. This decision sets the stage for a divergence in MPLS development; it creates a situation where some vendors will use the IETF standard for MPLS OAM while other vendors implement the ITU-T Recommendation for OAM. This situation ensures that the two product groups will not work together. While the impact may not be immediate, ongoing evolution along this path will jeopardize the globally interconnected Internet, which is an interoperable network of networks.
Russ Housley, IETF chair, commented; “The Internet we know today could not have come about without open, interoperable, global standards. After we have worked so long and so hard together to ensure that MPLS OAM products from all vendors around the world would be compatible with each other, I am surprised and disappointed by the action taken by the ITU-T today, which takes us off the path of global interoperability for this technology. The decision is all the more regrettable because the IETF is just completing work on the first major phase of extensions to MPLS OAM protocols for use in transport networks.”
Furthermore, this ITU-T SG15 action represents a serious breach of the IETF/ ITU-T Joint Working Team (JWT) agreement. This JWT was commissioned by the ITU-T and IETF to examine the feasibility of a single, collaborative solution to MPLS transport requirements. The team unanimously agreed that a single viable solution had been identified; their report was completed in April 2008 and accepted in December 2008. This JWT Report states not only that a single solution was possible but also recommended an approach where protocol development for MPLS-TP would be undertaken by the IETF. The IETF and ITU-T independently accepted and endorsed the JWT report. The ITU-T committed to the IETF that they would abide by the JWT recommendations and recognized the IETF as the design authority for MPLS. Furthermore, the JWT confirmed that it was technically feasible to extend the existing MPLS architecture to meet the requirements of a transport profile, now called MPLS-TP. Since the acceptance of the JWT Report, both organizations have worked constructively until now.
“Resolution 101 represented the clear wishes of the member states of the ITU, and was agreed at the ITU’s Plenipotentiary conference less than six months ago. That Resolution was agreed at the highest level of the Union, and yet SG15 has taken action that directly contradicts it,” said Lynn St. Amour, president and CEO of the Internet Society.
“The IETF will complete its work on a MPLS OAM specification, and the IETF leadership is considering the best way to proceed in light of this surprising development,” added Russ Housley. “At this point, our goal is to minimize the negative consequences of this unfortunate situation. The priority is to establish a measured and careful approach that protects the stability of the Internet while enabling it to grow to serve the entire world-wide population.”
Although the ITU-T SG15 decision is disappointing, in an ongoing pursuit of a globally interoperable solution, the IETF will continue to gather transport requirements and work to extend IETF MPLS forwarding, OAM, survivability, network management, and control plane protocols to meet those requirements through the IETF Standards Process.
When two non-interoperable standards are developed, there are only two possible outcomes: if both technologies are deployed, there will be confusion, if only one is deployed, the existence of the alternative is irrelevant. In this instance, there are believed to be commercial products in development for both proposals, so confusion appears inevitable.
Russ Housley concluded, “The IETF leadership continues to believe that a single OAM solution will better serve the continued growth of Internet, and we hope that the ITU-T leadership will also come to recognize the benefits of a single globally interoperable solution.”
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