Network Efficiency Trumps Speed, Says AT&T
What's at least as important is the ability to operate more efficiently and to turn up services more rapidly, and that will come with new colorless, directionless ROADM technology now on the market.
"Speed only helps if you are able to build networks in an efficient manner," King said in his keynote here Thursday.
Tunable directionless ROADMs are enabling point-and-click provisioning, and coherent detection eliminates the need for dispersion compensation modules (DCMs).
""We see a significant improvement in latency from not having those [DCMs], plus there is considerably simpler planning and a larger component of our legacy fiber network [that] is able to handle [the] highest bit-rate," King says.
The new ROADM control plane can find the most efficient routing from point A to point Z of a network, King added, and provision circuits in seconds or minutes -- a vast improvement over today's much more manual process of provisioning ROADMs.
"On a control plane-based capability at the ROADM layer, we can provision, change, or restore services in seconds or minutes, which is a tremendous revolutionary change," King said.
OTN switching also remains important to AT&T because, even as the company deploys 100G transport, the carrier's complex networks serve a variety of customers, many of whom won't be moving to 100G so quickly, King said. With OTN switching, AT&T can serve multiple line rates more efficiently, and maintain carrier-grade reliability with Sonet-like ability to survive multiple failures.
AT&T is looking for an industry solution that minimizes the cost of the packet/OTN interface with traffic shaping, King says.
Vendor solutions tend to fall into the "god box" category -- achieving convergence of the network layers with a hardware solution. Those might work for networks smaller or less complex than AT&T's.
"For me, the dream of the god box is still a dream -- I know I cannot prove a negative, that there will ever be a god box," King says. "I haven't seen one yet that will work for us, but that doesn't mean I won't see one. We continue to evaluate; we continue to ask you to bring us more."
Lacking a god box or industry standards that spell out how control planes from different network layers should talk to each other, AT&T will continue to require its vendors to "play nicely with others," and is perfectly happy to achieve multi-vendor interoperability through cooperative arrangements among its chosen set of vendors, well ahead of standards that sometimes stoop to the lowest common denominator of functionality, King said. — Carol Wilson, Chief Editor, Events, Light Reading