Multi-wavelength metro WDM sectioned ring for SAN extension under hot node scenario and variable traffic profiles

First-generation storage area networks (SANs) were designed to operate within limited distances. However, with the destructive effects of catastrophic events in a limited distance environment and the need of large organizations to connect their campuses over large geographic distances to share storage recourses among a larger number of users, the need of extending SANs has become essential. Several solutions were proposed to extend SANs over large distances. In this paper, a sectioned WDM metropolitan ring network is proposed as a suitable extension for SANs. SANs in a metropolitan WDM scenario create asymmetrical traffic and hot node scenarios. For the proposed network, two node architectures are considered, one with two fixed transmitters and the other with a tuneable transmitter. A tunable receive is used with both architectures. For the two fixed transmitters node architecture, two versions of medium access control (MAC) protocol are introduced. Simulation is carried out under both symmetrical and asymmetrical traffic. Performance of the sectioned ring is compared with that of the ring network architecture proposed in B. Pranggono and J.M.H. Elmirghani (2005)