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InterDomain Redundancy Path Computation Methods Based on PCE
Rie HAYASHI Eiji OKI Kohei SHIOMOTO
Publication
IEICE TRANSACTIONS on Communications
Vol.E91B
No.10
pp.31853193 Publication Date: 2008/10/01
Online ISSN: 17451345
DOI: 10.1093/ietcom/e91b.10.3185
Print ISSN: 09168516 Type of Manuscript: PAPER Category: Network Keyword: interdomain, redundancy paths, PCE (path computation element), path determination,
Full Text: PDF(2MB)>>
Summary:
This paper evaluates three interdomain redundancy path computation methods based on PCE (Path Computation Element). Some interdomain paths carry traffic that must be assured of high quality and high reliability transfer such as telephony over IP and premium virtual private networks (VPNs). It is, therefore, important to set interdomain redundancy paths, i.e. primary and secondary paths. The first scheme utilizes an existing protocol and the basic PCE implementation. It does not need any extension or modification. In the second scheme, PCEs make a virtual shortest path tree (VSPT) considering the candidates of primary paths that have corresponding secondary paths. The goal is to reduce blocking probability; corresponding secondary paths may be found more often after a primary path is decided; no protocol extension is necessary. In the third scheme, PCEs make a VSPT considering all candidates of primary and secondary paths. Blocking probability is further decreased since all possible candidates are located, and the sum of primary and secondary path cost is reduced by choosing the pair with minimum cost among all path pairs. Numerical evaluations show that the second and third schemes offer only a few percent reduction in blocking probability and path pair total cost, while the overheads imposed by protocol revision and increase of the amount of calculation and information to be exchanged are large. This suggests that the first scheme, the most basic and simple one, is the best choice.

