Backup reprovisioning with partial protection for disaster-survivable software-defined optical networks

Abstract

As networks grow in size, large-scale failures caused by disasters may lead to huge data loss, especially in an optical network employing wavelength-division multiplexing (WDM). Providing 100 % protection against disasters would require massive and economically unsustainable bandwidth overprovisioning, as disasters are difficult to predict, statistically rare, and may create large-scale failures. Backup reprovisioning schemes are proposed to remedy this problem, but in case of a large-scale disaster, even the flexibility provided by backup reprovisioning may not be enough, given the sudden reduction in available network resource, i.e., resource crunch. To mitigate the adverse effects of resource crunch, an effective resource reallocation is possible by exploiting service heterogeneity, specifically degraded-service tolerance, which makes it possible to provide some level of service, e.g., reduced capacity, to connections that can tolerate degraded service, versus no service at all. Software-Defined Networking (SDN) is a promising approach to perform such dynamic changes (redistribution of network resources) as it simplifies network management via centralized control logic. By exploiting these new opportunities, we propose a Backup Reprovisioning with Partial Protection (BRPP) scheme supporting dedicated-path protection, where backup resources are reserved but not provisioned (as in shared-path protection), such that the amount of bandwidth reserved for backups as well as their routings are subject to dynamic changes, given the network state, to increase utilization. The performance of the proposed scheme is evaluated by means of SDN emulation using Mininet environment and OpenDaylight as the controller

Running the Network Harder: Connection Provisioning Under Resource Crunch

“…If it is profitable, degrade such connections and serve the request. This is similar to the approach of [16], [20], [21].…”

“…Similar problems to ours have been analyzed in other works, however, without our goal of maximizing the network operator's profits. In [16], service degradation was used to reduce blocking and increase network survivability. Flexibility in both time-to-complete and desired bandwidth was studied in [17], to allow for reliable multi-path provisioning, and in [18] for deadline-driven scheduling.…”

“…This approach tends to find optimum degradation sets, since it investigates a large number of paths. 8) SP-k10: a similar approach as the one described in IV-C (which is also similar to [16], [20], [21]). Instead of only considering the single shortest path, this approach goes from the shortest to the k th shortest path and, for each path, degrades the cheapest connections that lie in it until enough capacity is freed for the crunched request.…”

Software Defined Optical Networks (SDONs): A Comprehensive Survey

“…17. Illustration of application layer modules of SDN based network reprovisioning framework for disaster aware networking [387].…”

“…Network resource reprovisioning is a process to change the network configurations, e.g., the network topology and routes, to recover from failures. A Backup Reprovisioning with Path Protection (BRPP), based on SDN for optical networks has been presented by Savas et al [387]. An SDN application framework as illustrated in Fig.…”