1 Introduction

Problems of network survivability have gained much attention recently due to the tremendous development of computer networks, expansion of new services and growing expectations of users. The main objective of this paper is to study the hop-limit approach applied to the flow assignment (FA) problem in survivable connection-oriented (c-o) network. In c-o networks prior to transmitting the data, a virtual connection is established and the data is carried along this connection. Popular network technique using this approach is MultiProtocol Label Switching (MPLS). The standard method to enable survivability in c-o networks is as follows. Each label switched path has a primary route and a backup route. The primary route is used for transmitting of data in normal, failure-free state of the network. After a failure of the primary route, the failed circuit is switched to the backup route that uses spare capacity not used...