Information Assurance

4.6. Multilayer Issues

As noted above, the networks composing the Internet are multilayer in nature and survivability and restoration can be addressed at multiple layers with different techniques at each layer. However, the majority of the literature focuses on providing survivability for various network technology (WDM, SONET, MPLS, ATM, IP, Overlay/Application) layers independently and multilayer issues are an area of ongoing research [49] that present several challenges.

Consider, for example, a two-layer backbone network such as an MPLS/WDM network. Survivability techniques in two-layer networks can be classified as survivability at the bottom layer, survivability at the top layer, and survivability at both layers, depending on the layer ...