From Survivability and Traffic Grooming in WDM Optical Networks
A subgraph-based routing strategy attempts to provide a passive form of redundancy to optical networks in the event of a given set of failure scenarios such as a single link failure or a single node failure. It is passive in that, before a connection is established, it is subjected to the constraints that it can be routed in the network as a fault free of any given set of failures, and is thus guaranteed in the event of a failure from the set. The end user experiences nominal interruption in service due to network state restoration and it is characterized in . The key characteristics of the subgraph-based routing strategy are as follows.
The redundancy in routing is provided using the resources available in the network.
Fault recovery network states are maintained throughout the operation of the network.
Subgraph fault tolerance provides a 100% guarantee for recovery from all possible predefined failure states.
Subgraph routing is a pro-active path-based fault tolerance strategy.
The network state must be altered to accommodate the new topology of the network caused by a failure state.
The first characteristic highlights one of the most important aspects of the strategy; it does not require the allocation of system transmission resources to ensure recoverability after the detection and location of a link failure. Simply put, there is no explicit link capacity lost due to the routing of backup connections because no active backup connections exist in this strategy. The second...
Products & Services
Fire alarm control panels (FACPs) transmit signals between fire detection devices and alarms, suppression systems, and monitoring centers. This device reduces the potential for fatalities and property loss from structure fires.
Topics of Interest
Overview Although the failure of a single component such as a link or a node is the most common failure scenario, it is possible to have multiple links fail simultaneously. In particular, double-link...
In the previous chapter we reviewed various graph-theoretical techniques for determining graph similarity. Of particular interest to the work presented here are the distance measures based on the...
Introduction Regardless of how hard administrators work to protect their networks and systems from disaster, sometimes the worst occurs. Servers are subject to hardware failure due to age, overuse,...
3.14 MPLS, MPλS, AND GMPLS The generic multiprotocol label switching (GMPLS) protocol is a generalization of a previously defined IETF multiprotocol wavelength switching (MPλS) in...
Adding fault tolerance Within any enterprise-wide system, if one node fails, you have a problem! Within a hierachical model, this could effect the mail delivery for the entire company so adding fault...