Sub-optimal routing in unreliable packet switched computer communication network

The paper is devoted to introduce and describe an approach leading to sub-optimal traffic routing in unreliable packet-switched computer network. It is assumed that average packet delay in unreliable network may be estimated based on average packet delays obtained both for the reliable and the unreliable networks; it is approximated by linear function of both considered delays. It is also assumed that optimal routing in network, when failure of particular channel occurs may be replaced by re-routing performed only in some separate part of the network containing the channel with failure.