The Optical Control Plane Is Finally Hot
For many years, the optical control plane has been a relatively dry topic at optical events. Topics such as 100G, switched OTN, and colorless, directionless, contentionless (CDC) ROADMs have had the spotlight, while control plane technology progressed rather quietly. This year, the optical control plane takes center stage, and we expect much discussion and debate in New York. Here are some of the factors driving the surge in interest:
- OpenFlow and Software-Defined Networking (SDN): These two terms are all over the trade press right now, including in Light Reading. OpenFlow is a protocol, and SDN is the broader term for the physical separation of the control and data plane in networks. OpenFlow is seen as a great fit for data centers, and its applicability for more complex telco environments is being hotly debated. Regardless of where operators stand on OpenFlow specifically, its existence has sparked a new round of investigation of how SDN can be applied to telco networks. Currently, there is a lot of interest in Path Computation Element (PCE) as a telco-oriented form of SDN. Born of the IETF, PCE moves some control to the cloud (the path computation function) but leaves much of the intelligence on the elements. While PCE has momentum, we are also hearing about OpenFlow, so none of this has been decided.
- Switched OTN and CDC ROADMs Enable Control Planes: These two trends in network hardware have opened up new possibilities for the optical control plane. For the past decade, optical control planes have been associated with switched Sonet/SDH networks, primarily in the core. Now, as switched OTN is moving to replace switched Sonet/SDH, the optical control plane is being ported over to this new Layer 1 transport elements. In addition, switched photonic networks -- enabled by these new CDC ROADMs -- have opened up the possibility of an optical control plane for the photonic layer. This is being standardized by the ITU-T as WSON. And finally, as operators have this control plane functionality up and down the OSI stack, interest has arisen to define and build multi-layer control planes through which all of these control plane layers can interact. Again, this is all new and much is to be done.
Beyond 100G Gets Real
For the past five years at our optical events, we have been discussing the coming of 100G transport. Now, 100G is here and shipping in volume. At POTE 2012, we turn our attention to what lies beyond 100G -- with an entire panel dedicated to the terabit transport topic. We believe the timing is right for this industry discussion, as there is much that must be decided and history shows that it takes about five years for a new rate to move from lab experiments to commercial deployments. One of the first issues to be resolved is: What will the next-gen bit rate be? On the table are 400G and 1T, as well as a very real possibility that the next line-side rate will be a variable rate composed of building blocks that can be added and subtracted. The key enabler here is the superchannel -- a composite signal built from multiple sub carriers. This superchannel is widely viewed as the only viable way for suppliers to get to terabit channel rates in the next ten years.
Beyond P-OTS and CESR
We revisit the topic of packet-optical integration to learn the state-of-the-art and to understand the likely future trajectory. Not too long ago, many were skeptical that operators would ever deploy hybrid products that combine packet switching and TDM; now these systems are widely deployed by operators around the world. Moving forward, greater emphasis (and development) rests on the packet side of these hybrid products. Some topics to discuss include: the current state of the MPLS-TP standard, the role of switched OTN in the metro, and how next-gen ROADMs may change architectures. Another very interesting topic is how high up the OSI stack suppliers should go in integrating packet technology into transport systems. Layer 2.5 has been the ceiling, but we are starting to see a move to add IP.
These are just a few the topics we’ll discuss at POTE 2012. We hope to see you in New York!
— Sterling Perrin, Senior Analyst, Heavy Reading