There's a funny thing about the OSI stack: It's not just an abstraction of a communication system, but also a social hierarchy that creates a kind of class system in the engineering world.
Think about it. Those folks working on the layers below you -- what do you call them? If you're like me, you've spent most of your working life calling them "plumbers." If pushed, you would admit you couldn't get along without them, but there is still a kind of superiority implied: What you're working on is more valuable, more clever, and, obviously, a lot more interesting.
For me, the teams working on optics have always been the plumbers. So imagine my surprise when in a meeting between our SDN and IP router teams, the SDN folks, who work closer to the application layer, referred to us IP "infrastructure" folks as -- you guessed it -- "plumbers." That was putting the shoe on the other foot!
After getting over my surprise, I started thinking about how unhelpful this whole plumbing thing is. After all, the future of this industry requires a convergence of IP and optics: It's time to give the optics guys some overdue respect and dig into the world of optical transmission and switching.
Working with the experts who are pushing the limits of technology on a daily basis exposes the nuances of the technology that you could never learn from books or the Internet. One thing for sure is that optical networking is very different from IP networking. The base system designs and some of the underlying technology are similar, but the design goals and resulting optimizations are quite different.
Here are four key observations I'd like to share:
The first problem to solve is automating the optical layer, because much of what happens, even today, involves hands-on setup. ROADMs were a great start, but they only allow automation of the middle of the route, but not the ingress and egress points. Next-generation ROADMs solve a lot of these issues by making them colorless, directionless, contentionless (CDC) and, for networks over 100 Gbit/s, flexible (CDCF). But the key will be getting the routing layer to talk intelligently to the optical control layer and vice versa.
Again, there is a lot of sophisticated and tricky maneuvering happening at the optical layer, which few IP engineers recognize or understand. While that was OK in the past, it is entirely insufficient today. We're on the cusp of a major shift in how networks are architected and there are just too many opportunities to build those networks better and more efficiently by bringing together IP and optical technologies.
— Steve Vogelsang, VP Strategy and CTO, IP Routing and Transport Business Division, Alcatel-Lucent