With the advent of Sonet framer chips that support the link capacity adjustment scheme (LCAS), virtual concatenation and the generic framing procedure (GFP), Sonet designs become simpler for the market at large. The recent arrival of ADM-on-chip designs from the likes of Agere Systems, Galazar Networks, Parama Networks and PMC-Sierra have made it feasible to stuff ADM functions and true Sonet termination into the confines of a 1U "pizza box."
Second time around
The brave new world of edge aggregation sparked a revolution of sorts at Supercomm. Market analysts were toasting startups that offered systems for the "multiservice edge," while extolling Nortel Networks Inc. (Kanata, Ontario) for defining a category between public and private networks that was something more than an edge router or a glorified Ethernet switch.
Pioneers trolling the edge included Mangrove Systems Inc. (Wallingford, Conn.), which launched an edge-to-central-office system at Supercomm based on what the company calls MetroMPLS, and Hatteras Networks Inc. (Research Triangle Park, N.C.) and World Wide Packets Inc. (Spokane, Wash.), which demonstrated Ethernet access systems for carriers that could coexist with Sonet and MPLS systems in the metropolitan core.
But there was something all too familiar about the accolades to the edge. Three years ago, as the recession hit the local carriers with full force, a new breed of Sonet ADM was promising to be Ethernet-friendly. Meanwhile, the IEEE's 802 LAN/WAN group had defined a new metro topology, resilient packet ring (RPR), that was touted as the way to bring Sonet redundancy to a simpler, packet-optimized world.
Interest in 802.17 RPR remains strong in certain Asian markets, and the RPR Alliance was in Chicago last week touting the benefits of the technology as a transition point between Ethernet in the enterprise and Sonet in the metro core.
Discover the benefits of scalable backbone and network services for application and cloud providers.
Network automation is gaining momentum. Here's how you can drive this powerful technology to its full potential.
Subsea cable alternatives can provide a level of comfort for those concerned about disruptions. Realistically, they will continue to play a small, but critical role in the short term.
