PROCEEDINGS ARTICLE | November 19, 2007
Proc. SPIE. 6783, Optical Transmission, Switching, and Subsystems V
KEYWORDS: Wavelength division multiplexing, Multiplexing, Networks, Switching, Head, Optical networks, Switches, Signal processing, Legal, Telecommunications
IP/WDM traffic grooming is a scheme that let different fine-grained IP layer Packet Label Switched Paths efficiently
share the coarse-grained WDM layer lightpath. Choosing those nodes with high nodal degree as the terminals of
lightpaths can save the transfer times of Packet LSP, thus on average each lightpath can hold more service to achieve
better resource utilization and network throughput. To improve the resource utilization, this paper proposes the
Topology-Based Lightpath Establishment Algorithm (TBLEA) which employs network topological characteristics to
build more efficient lightpaths whose terminals are with high nodal degree. In the algorithm, a long lightpath, which is
potentially less efficient, might be cut into several shorter lightpaths based on the topology characteristics and remaining
resource of nodes in the primer lightpath. The algorithm has the advantages that not only the terminal nodes but also the
length of new lightpath can promise to improve the PSC and LSC resource utilization. In the implementation of the
TBLEA algorithm, a two-layer virtual graph helps to calculate the explicit integrated route to build Packet LSP, and
different formulas are adopted to calculate the total costs of existing lightpaths and new lightpaths. A long lightpath
might be cut into shorter lightpaths on the basis of the node weight, which is determined by the nodal degree and relative
remaining resources. And iterative procedures offer the loop-free optimization of the changed explicit route for Packet
LSP.
