Book contents
- Frontmatter
- Contents
- Preface
- Acknowledgments
- 1 Optical networking technology
- 2 Design issues
- 3 Restoration approaches
- 4 p-cycle protection
- 5 Network operation
- 6 Managing large networks
- 7 Subgraph-based protection strategy
- 8 Managing multiple link failures
- 9 Traffic grooming in WDM networks
- 10 Gains of traffic grooming
- 11 Capacity fairness in grooming
- 12 Survivable traffic grooming
- 13 Static survivable grooming network design
- 14 Trunk-switched networks
- 15 Blocking in TSN
- 16 Validation of the TSN model
- 17 Performance of dynamic routing in WDM grooming networks
- 18 IP over WDM traffic grooming
- 19 Light trail architecture for grooming
- Appendix 1 Optical network components
- Appendix 2 Network design
- Appendix 3 Graph model for network
- Appendix 4 Graph algorithms
- Appendix 5 Routing algorithm
- Appendix 6 Network topology design
- References
- Index
3 - Restoration approaches
Published online by Cambridge University Press: 18 December 2009
- Frontmatter
- Contents
- Preface
- Acknowledgments
- 1 Optical networking technology
- 2 Design issues
- 3 Restoration approaches
- 4 p-cycle protection
- 5 Network operation
- 6 Managing large networks
- 7 Subgraph-based protection strategy
- 8 Managing multiple link failures
- 9 Traffic grooming in WDM networks
- 10 Gains of traffic grooming
- 11 Capacity fairness in grooming
- 12 Survivable traffic grooming
- 13 Static survivable grooming network design
- 14 Trunk-switched networks
- 15 Blocking in TSN
- 16 Validation of the TSN model
- 17 Performance of dynamic routing in WDM grooming networks
- 18 IP over WDM traffic grooming
- 19 Light trail architecture for grooming
- Appendix 1 Optical network components
- Appendix 2 Network design
- Appendix 3 Graph model for network
- Appendix 4 Graph algorithms
- Appendix 5 Routing algorithm
- Appendix 6 Network topology design
- References
- Index
Summary
The restoration schemes differ in their assumptions concerning the functionality of cross-connects, the traffic demand, the performance metric, and the network control. Survivability paradigms are classified based on their rerouting methodology as being path-/link-based, execution mechanisms as centralized/distributed, by their computation timing as precomputed/real time, and their capacity sharing as dedicated/shared. This classification is shown in Fig. 3.1.
Pro-active vs. reactive restoration. A pro-active or reactive restoration method is either link-based or path-based. In a special case, a segment-based approach can also be used. In a segment-based detouring, a backup segment is assigned for more than one link. A link may be covered by more than one segment. The restoration path, as shown in Fig. 3.2, is computed for each path. In the case of a link failure, the backup segment is used.
Link-based restoration methods reroute disrupted traffic around the failed link, while path-based rerouting replaces the whole path between the source and the destination of a demand. Thus, a link-based method employs local detouring while the path-based method employs end-to-end detouring. The two detouring mechanisms are shown in Fig. 3.3. For a link-based method, all routes passing through a link are transferred to a local rerouting path that replaces that link.
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- Information
- Publisher: Cambridge University PressPrint publication year: 2006