Provisioning nonconflicting restoration policies in a multiservice IP network
Joseph B. Kroculick, Cynthia S. Hood · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 2001
Limited attention has been paid to the interactions of service restoration protocols that operate during a fiber cut to restore connectivity between communications equipment. Historically, restoration protocols were deployed only at the SONET layer in telephony networks. SONET frames that carried voice-grade signals such as a T1 or T3 would be redirected to protection path over architectures that supported bidirectional communication. With the advent of new communication technologies such as ATM, IP and WDM, a cable cut can affect multiple routing processes at each of these layers even if a particular network region only supports a few of these technologies. For example, restoration processes at an arbitrary layer in adjacent networks might trigger if lower-layer protocols don't finish within specific deadlines. With the growth of data traffic and a wide range of service offerings, the telecommunication networks of the future are growing more complex, requiring multiple interactions between software systems. Failures will be difficult to pinpoint and the cooperation of the repair processes will be key to ensure that services traversing multiple networks are not interrupted.