A multistate multipath provisioning scheme for combating node failures in telecom mesh networks

Telecommunication networks spanning large areas are subject to various failures. A survivable network provisioning scheme addressing multiple levels of network failures, especially disaster failures which may take out many network components, is desirable in the future Internet. In this study, we propose and investigate the characteristics of a multistate multipath provisioning scheme for telecom mesh networks. We define different provisioning states which correspond to protection approaches against a wide range of failures, including single-link failure (SF), multiple-link failure (MF) (which is one form of a shared-risk group (SRG)), and disaster failure (DF) (initially the failure of a node and all its surrounding links, which is another form of a SRG). We integrate the conventional primary-backup method with reprovisioning and degraded service (i.e., a reduced level of service vs. no service at all) into a state-transition model to handle different levels of failures. A pre-defined level of service is guaranteed for premium customers even if the service cannot be fully recovered. Results from our simulation experiments show that connection dropping probability due to a node failure can be significantly reduced for a small extra cost for SF protection.