Optical Networking Best Practices Handbook

1.7. SUMMARY AND CONCLUSIONS

This chapter described IP and integrated optical network solutions and discussed a network architecture for an optical and IP integrated network as well as its migration scenario. Also, this chapter took a look at a framework for an incremental use of the wavelengths in optical networks with protection. The framework provides a flexible network structure against the traffic change. Three phases (initial, incremental, and readjustment phases) have been introduced for this purpose.

In the incremental phase, only the backup lightpaths are reconfigured for an effective use of wavelengths. iIn the readjustment phase, both primary and backup lightpaths are reconfigured, since an incremental setup of the primary lightpaths tends to utilize the wavelengths ineffectively. In the readjustment phase, a one-by-one readjustment of the established lightpaths toward a new logical topology is performed so that a service continuity of the optical networks can be achieved. The branch-exchange method can be used for that purpose. However, improving the algorithm for minimizing the number of the one-by-one readjustment operations is necessary; this issue is left for future research.

1.7.1. Differentiated Reliability in Multilayer Optical Networks

Current optical networks typically offer two degrees of service reliability: full (100%) protection (in the presence of a single fault in the network) and no (0%) protection. This reflects the historical duality that has its ...