Denver Motorola Computer Group and NTT Corp. of Japan have jointly proposed a multicast version of the multiprotocol label switching standard, and the Internet Engineering Task Force has agreed to form a project within its MPLS working group.
Multicasting will improve quality-of-service capabilities and deterministic behavior for broadband Internet Protocol transport, the companies said.
They had demo'd M-MPLS operating on PC-based routers at the MPLScon exhibition in Washington last month, using client implementations of Internet Group Management Protocol to let clients join or leave multicasting groups.
John Fryer, director of product management for the NetPlane group of Motorola, said NTT had searched for a U.S. partner to help develop the multicast since early 2002, when Fryer's NetPlane Systems group was part of Mind-speed Technologies. NetPlane had developed a reputation as a base of expertise for ATM and MPLS protocols, and NTT was eager to work with a focused protocol specialist.
Open telecom standards
Since Motorola acquired the NetPlane group last year, the joint effort for M-MPLS development garnered more support, since Motorola saw it as a way to drive open telecom system standards.
Seisho Yasukawa, senior research engineer at NTT Network Services Systems Laboratory, said the force driving what NTT calls "tree-explicit route objects" came from realizing that streaming video scaled to millions of users could not use the simple forwarding trees common in point-to-point unicast routing protocols. Instead, the tree-explicit route-object method developed at NTT allows arbitrary shapes of trees for point-to-multipoint traffic, which can be configured as cost-optimized Steiner trees or as other router tree types.
Content servers will not have to implement special software for multicasting, Yasukawa said. Instead, an edge router that terminates a label-switched path for MPLS can retain information about the multicast trees, allowing clients to use standard internal gateway protocols and group management protocols.
The IETF has set late 2004 as the time when a draft of an M-MPLS standard should be submitted for consideration as a request-for-comment standard.