Rapid and Efficient Protection for All-Optical WDM Mesh Networks

Abstract

Survivability becomes increasingly critical in managing high-speed networks as data traffic continues to grow in both size and importance. In addition, the impact of failures is exacerbated by the higher data rates available in optical networks. It is therefore imperative to address network survivability in an efficient manner in order to design and operate reliable networks.Transparent optical networks (TONs) provide several advantages over optically opaque networks for supporting the growing communication demands, but suffer from several drawbacks that reduce the efficacy of most applicable capacity-efficient survivability techniques. In this paper, we present a protection algorithm (for single link and/or node failures) called Streams. Streams protection is identical to 1:1 dedicated path protection in terms of recovery speed, but requires significantly less capacity.We study both online non-dynamic routing as well as (online) dynamic provisioning scenarios to compare Streams with dedicated and shared path protection in terms of capacity, blocking probability, path lengths, and recovery time/data loss, and report the relative tradeoffs between the different protection schemes in detail. Our results show that our simple heuristic for Streams under online provisioning scenarios offer attractive tradeoffs in terms of blocking, recovery speed, data loss and implementation overhead. We also briefly cover simple ILP solutions to address static offline routing problems, and show that the Streams protection scheme is also efficient under offline routing scenarios as well.

Impairment-Aware Dynamic Routing and Wavelength Assignment in Translucent Optical WDM Networks

“…BFS-RWA has been tested using both real and synthetic network topologies. The real network topologies used in the simulations include NSFNET (14 nodes) [27], ARPANET (21 nodes) [27] and USANET (24 nodes) [28]. (calculated using the OSNR tool parameters, considering only class 1 impairments) was used in the simulations.…”

“…As expected, the blocking probability decreases, as the number of regenerators at the regeneration sites increases. This effect can be seen clearly in medium sized networks having [24][25][26][27][28][29][30] nodes. In small translucent networks, the number of regeneration capable nodes is very small (usually 1 or 2) and the number of lightpaths requiring regeneration is also relatively low.…”

QoT-guaranteed protection: Survivability under physical layer impairments

“…1:1, in contrast, utilizes backup paths only after failures and takes about 40-50ms for the data to reach the destination from the time of the failure. The recovery is considered to be complete when the data reaches the destination, but it is important to note that 1+1 and 1:1 both incur the same amount of data loss, which occurs while the network is unaware of the failure (about 10ms detection) and until data is physically placed on the backup path (another 10ms) [12]. We focus on 1:1 to avoid the extra cost of 1+1 (especially with QoT).…”

“…Shared path protection (SPP) schemes offer significant reduction in capacity usage, but have slower recovery. Since cost-efficiency is an important aspect of network design and management, shared protection has gain much attention in the literature [13], [14], [15], [11], [12]. In this paper, we evaluate both DPP and SPP.…”

A hybrid protection strategy based on node-disjointness against double failures in optical mesh networks

“…Based on various protection methods mentioned above, most previous research works focused on designing various protection algorithms for single-link/node failures and double-link failures [1][2][3][4][5][6][7][8][9][10], few references aimed at doublenode failures [11]. Generally, protection approaches for link failures need to pre-provision link-disjoint backup paths for working paths, and protection approaches for node failures need to pre-provision node-disjoint backup paths for working paths.…”