IP Over Glass, Who Cares?
Sounds technologically fascinating. But is it practical? Many experts say no.
"There are few systems if any that can put IP over WDM optics," says Scott Clavenna, principal analyst at Pioneer Consulting http://www.pioneerconsulting.com . "But the trend is moving away from efforts to put IP directly on glass. It's more impressive as a demonstration than anything else."
At one time, the idea of putting IP directly over fiber seemed like the next logical step in simplifying carrier networks. This would eliminate the need for expensive Sonet and ATM gear, while greatly reducing the complexity of managing the network.
But views have changed. While simplifying the network is still the main goal, many carriers are turning to optical switches from vendors like Sycamore Networks Inc. http://www.sycamorenet.com to act as middlemen between IP routers and DWDM systems. Using IP centric protocols, optical switches allow for dynamic control of bandwidth by allowing traffic to be switched across different wavelengths giving them more flexibility in deploying new services.
But when an IP router is connected directly to a DWDM system, it doesn't allow traffic to be switched along different light paths throughout the network. Essentially, this configuration allows carriers only one option, a static point-to-point pipe.
"That is a lot of bandwidth to point in one direction," says Rick Thompson product marketing manager for Sycamore. "This announcement is basically a non-event. Connecting optical switches to routers is where there really needs to be interoperability."
This is why Sycamore has led the charge in helping organize the Optical Domain Service Interconnect (ODSI), a group of over 50 service providers and vendors that are working together on standards for routing, optical switching and optical transport systems. (see Third Front Opens on Standards War)
It is important to note that Juniper and Ciena do not endorse IP over glass as the only solution. Both vendors are also members of the ODSI, and Ciena also has its own optical switch, MultiWave CoreDirector.
by Marguerite Reardon, senior editor, Light Reading