Traffic Engineering in Optical Networks

The article by Palmieri, 2008 provides a very straightforward explanation of traffic-engineering:

Traffic-engineering functions as an assistant to routing and switching infrastructures. The use of TE aims on balancing the usage of a network and avoid congestion resultant from uneven traffic distribution.

Currently, dynamic routing is protocols rely on shortest paths to forward traffic. This practice while conserving network resource also causes some resources to be over used and others are under used. Also, traditional routing protocols do not consider specific requirements of some traffic flow as QoS and bandwidth.

A traffic-engineering application must provide control over the placement of traffic flows in a network domain promoting a better usage and a manageable network. A traffic-engineering application adequate for a Optical network present the following basic functions:

-Traffic monitoring, analysis and aggregation. Collects traffic statistics and aggregate or analyze them for later use.

-Bandwidth demand projection. Used for sub-sequent allocation, the projection estimates the bandwidth requirements for the near future based on statistics.

-Reconfiguration trigger. Set of policies that decide when a network needs to be reconfigure. The decision is based on operational areas, traffic measurements and bandwidth predictions.

-Topology design. Based on traffic measurements and predictions, it aims on optimizing a graph for specific objectives.

-Topology mitigation. Algorithms used to coordinate the migration to a new topology.

Palmieri, F. (2008) “GMPLS Control Plane Services in the Next-Generation Optical Internet”, The Internet Protocol Journal, Vol.11, Number 3, September 2008.