The Forcer Concept and Express Route Planning in Mesh Survivable Networks
Wayne D. Grover
c/o TRLabs (University of Alberta),
#800 Park Plaza, 10611-98 Ave., Edmonton, Alberta, Canada, T5K 2P7
Email: grover_AT_trlabs.ca
Danny Y. Li
c/o W. Grover, TRLabs (University of Alberta),
#800 Park Plaza, 10611-98 Ave., Edmonton, Alberta, Canada, T5K 2P7
Abstract
To date, mesh network design theory has been developed for the case where
working and protection capacity is terminated at every node. It is recognized
that express routes, which bypass some nodes en-route, would decrease the
total
DCS port costs but it has been unclear how to incorporate nodal bypass
planning
in the optimal spare capacity design for a mesh-restorable network. An
important issue is whether the introduction of nodal bypasses will increase
the
total spare capacity needed for restorability, due to a reduction of
restoration re-routing flexibility. To address these questions, we introduce
the forcer concept for analysis of the relationship between working and spare
capacity in a mesh restorable network. We apply the forcer concept to show
theoretically why bypass in fact need never require an increase in sparing and
may actually permit a decrease in some cases. In tests to validate and
exploit
these findings, an average reduction of 12% in total spare capacity and 16% in
DCS port count totals were obtained simultaneously with an Integer Programming
optimization. These savings are relative to an already optimized fully
terminated network design. The work thus contributes to greater theoretical
understanding and design cost-effectiveness for mesh-based restorable
networks.
Keywords: survivable networks, mesh networks, forcer concept, express routes, nodal
bypass, optimization
JNSM: Vol. 7, No. 2, 1999
The Forcer Concept and Express Route Planning in Mesh Survivable Networks [Vol. 7, No. 2, 1999]
NOTE: only abstract of paper available on-line
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