Traffic engineering and routing in survivable multi-service networks

This paper presents a new framework for Traffic Engineering (TE) of primary and backup paths and routing of Quality of Service (QoS) and Best-Effort (BE) flows in multi-service backbone networks capable of surviving against single or multiple node and/or link failure(s). The aforementioned framework involves an off-line and an on-line phase. In the off-line phase either a method based on an Integer Linear Programming (ILP) TE problem or a method based on a heuristic TE algorithm provides the primary and the backup routes (where required) for the QoS-guaranteed flows and the routes for the BE flows. In the on-line phase the QoS and BE flows are routed based on the outputs of the off-line phase. In the case that one or more primary paths fail the corresponding backup paths are used for restoration. However, if one or more backup paths also fail or a backup path is not defined dynamic restoration is applied. Test results regarding the two off-line TE methods are presented.