Logical Network Mapping With Content Connectivity Against Multiple Link Failures in Optical Metro Networks
Giap Dang Le, Andrea Marotta, Sifat Ferdousi, Sugang Xu, Yusuke Hirota, Yoshinari Awaji, Massimo Tornatore, Biswanath Mukherjee · 2019
Network connectivity has been the traditional metric for network survivability against failures. In case of a disaster, network connectivity may not always be guaranteed due to multiple link failures. With the shifting service paradigm towards cloud computing/storage, some network services can still be provided if a content replica is available in all disconnected network segments. As a result, content connectivity has been introduced as an additional metric for network survivability under disasters. Content connectivity is defined as the reachability of content from every node in a logical topology under a given failure scenario. In this work, we investigate the content-connectivity problem in optical metro networks in the case of multiple ( n) link failures. We consider the problem of mapping a logical topology over an optical metro network such that every node in the logical topology can reach at least one data center hosting the content after n-link failures. We formulate the problem as an integer linear program to minimize total network resource usage. We provide a cost comparison between content connectivity and network connectivity under typical failure scenarios.