By Jim Theodoras
Shiny gold plated laser housings. Gleaming AWG wafers. Rainbow colored ribbon cables. Stuff. There is something exciting (dare I say tantalizing) about seeing new gadgets, and being the first to see, touch, and feel them. It always seems much of the buzz at #OFCNFOEC each year centers on the tangible. XFPs, QSFPs, CFPs, TOSA’s, ROSA’s, ribbon cables, etc. Yet, this year, I challenge attendees to resist their natural tendencies honed over centuries of evolution, and to look beyond mere devices.
Often the largest leaps in technology cannot be held in the hands. Theoretical breakthroughs, progress milestones reached, algorithms developed, software coded. This year I suggest we revisit an old friend: the control plane. Huge advances were made almost two decades ago in having all the layers of the OSI networking stack work together for optimal communication. Then WDM came along and made all the elegant solutions very messy. It seems dealing with colors made networks inflexible. Ever since then, much of #OFCNFOEC has centered on making colored transport networks as flexible as grey.
After Billions dollars of industry investment over the years, static colored networks have given way to agile core networks, finally reaching the same level of flexibility that grey networks had many years ago (a fact SONET proponents would be eager to point out). But what to do with this flexibility? It turns out the optical transport layer is not smart enough to switch intelligently; it needs to be commanded from higher layers that see the big picture, which is where the control plane comes in. Have you noticed the return of Router vendors and Service Providers to #OFCNFOEC? That is not merely a coincidence. The next frontier in optical communications is routers dynamically controlling the optical transport layer, automatically optimizing the links between themselves.
Fortunately, visionaries at standards bodies have kept far ahead of the technology curve, and there are well developed protocols to make this happen. Routers running IP/MPLS can talk to the optical transport layer running GMPLS via a UNI interface as defined by the OIF or IETF. Path computation elements and clients are defined to determine the optimal path for information to flow. When the path needed involves multiple network domains, the necessary parameters can be tunneled using Generic Routing Encapsulation. It sounds complicated, and it is; however, it works very well, just as network architects envisioned. Their dream has become reality. So this year, when walking the show floor, keep an eye out for advances in the control plane. It may not be glitzy, but control plane advances are ushering in a new era in optical communications.
Jim Theodoras is Senior Director of Technical Marketing at ADVA Optical Networking, where he actively promotes the company’s portfolio of Optical+Ethernet transport products and related technologies. He has over 25 years of industry experience in electronics and optics, spanning a wide range of diverse topics. Jim is a past President of the Ethernet Alliance, holds 16 patents in the field of telecommunications, and is a frequent contributor to industry publications.
Posted: 15 February 2012 by
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