Optical Networking

Optical networks can send vast amounts of data (IP flows) through lambda connections.

These connections are established through multi-service optical

switches, which have the capability to perform forwarding decisions at different levels in the protocol stack. As a result, long and big IP flows (elephant flows) could be moved from the packet-level to the optical-level. This move could result in a better QoS for both elephant flows and remaining IP flows: the former would have no jitter and plenty of bandwidth at the optical-level; the latter would be better served due to the off-load of elephant flows.

The detection of IP flows and the management of lambda-connections are important tasks to achieve the desired move. Two approaches are currently used for that 

[1]: Conventional management 

[2]: GMPLS signaling. 

The former is characterized by a centralized management entity (e.g., human manager or an automated management process) that is in charge of establishing lambda-connections and deciding which IP flows should be moved to the optical-level. In contrast, the latter is characterized by the fact that optical switches coordinate the creation of lambda-connections among themselves. The decision which IP flows will be moved to the optical level however should be taken by a centralized management entity, or by the entities responsible for the generation of the data flow.

However, there are several problems using these approaches. Both approaches require human interaction to detect flows and manage lambda-connections. This interaction may be slow, since humans need time to perform those tasks, and it is also error prone.

One of the major issues in the networking industry today is tremendous demand for more and more bandwidth. Before the introduction of optical networks, the reduced availability of fibers became a big problem for the network providers. However, with the development of optical networks and the use of Dense Wavelength Division Multiplexing (DWDM) technology, a new and probably, a very crucial milestone is being reached in network evolution. The existing SONET/SDH network architecture is best suited for voice traffic rather than today’s high-speed data traffic. To upgrade the system to handle this kind of traffic is very expensive and hence the need for the development of an intelligent all-optical network. Such a network will bring intelligence and scalability to the optical domain by combining the intelligence and functional capability of SONET/SDH, the tremendous bandwidth of DWDM and innovative networking software to spawn a variety of optical transport, switching and management related products.