Protection Interoperability for WDM Optical Networks

The failure of a single optical link or node in a Wavelength Division Multiplexing (WDM) network may cause the simultaneous failure of several optical channels. In some cases, this simultaneity may make it impossible for the higher level (SONET or IP) to restore service. This occurs when the higher level is not aware of the internal details of network design at the WDM level. We call this phenomenon ``failure propagatio

A Path Selection Method in ATM using Pre-Computation

An algorithm that pre-computes a list of routes for each node in the network. An alternate route is also computed in case of overload of the primary one. Simulations show that this algorithm provides routes as good as On-Demand ones

A Dynamic Hierarchy of Intelligent Agents for Network Management

Routing as well as the management of communication networks that support hybrid types of communications requiring quality of service is a hard problem. We present here a framework1 that decomposes the network into a hierarchy of abstract views of the network that summarizes the available bandwidth resources and highlights bottlenecks in the network in order to reduce the complexity of the previously mentioned tasks. This framework can easily be distributed to a hierarchy of intelligent agents. This framework is technology independent and can be applied to any connection-oriented communication network

Design Protection for WDM Optical Networks

With WDM networks, the failure of a single link or component may cause the simultaneous failure of several optical channels, potentially making impossible the restoration by rerouting in higher layers directly using the optical network (SDH, ATM, IP). To address this, we introduce the concept of Design Protection, which aims at making such failure propagations impossible. We present the Disjoint Alternate Path (DAP) algorithm which places optical channels in order to maximise design protection. We show the result on the example of the ARPA-2 network. Keywords: WDM, optical network, survivability, routing, tabu search. 1 Introduction The large bandwidth of optical fibres have made them attractive for high-speed networks. The use of Wavelength Division Multiplexing (WDM) allows aggregation of many channels onto a single fibre without the need of high-speed optoelectronic devices for end-users [1, 2, 3, 4, 5]. It is the simplicity of this multiplexing scheme, permitting a relatively e..