Survey on Dependable IP over Fiber Networks

Algorithms for Failure Protection in Large IP-over-fiber and Wireless Ad Hoc Networks

“…Alarms can be generated by devices at the optical, SDH/SONET or IP layer. A full review of the available monitoring information is provided in [3]. Failure location in IPover-WDM networks is known to be NP-hard [4] and several algorithms have been proposed to solve this intractable problem in the literature (see [3] for a complete review of the existing failure location algorithms).…”

“…A full review of the available monitoring information is provided in [3]. Failure location in IPover-WDM networks is known to be NP-hard [4] and several algorithms have been proposed to solve this intractable problem in the literature (see [3] for a complete review of the existing failure location algorithms). Although many researchers [4] have suggested that failure location algorithms must be able to cope with alarm errors, most location algorithms today avoid this issue because of the complexity of covering all possible failures and corrupted alarms.…”

“…The inference of internal link properties given end-to-end observations is called network tomography. A detailed survey of the current tomography techniques is provided in [3]. In most networks end-to-end data do not provide enough information to identify the exact link loss rates but enough to identify the worst performing links.…”

“…This issue is especially important in the IP-over-WDM architectures, where one physical link can carry many lightpaths, and thus where a single physical link failure may bring down a large number of logical links. A survey of different approaches for providing survivability of IP-over-WDM networks can be found in [3]. In this paper we consider exclusively the IP restoration approach that was shown to be effective and cost-efficient (see e.g., Sprint network [11]).…”

“…The probability P rob li path that l i will be unsurvivable on a path is the probability that it will be unsurvivable on at least one physical link of the path. The probability P rob li p that l i will be unsurvivable on a physical link p of the path is the probability that l i will cause unsurvivability when routed together with any of the other logical links l j which use p, 3 which is estimated in z li,lj . We use formula (5) to estimate P rob li p and formula (6) to estimate P rob li path .…”