RATES: A server for MPLS traffic engineering

It has been suggested that one of the most significant reasons for MPLS net work deployment is network traffic engineering. The goal of traffic enginee ring is to make the best use of the network infrastructure, and this is fac ilitated by the explicit routing Feature of MPLS, which allows many of the shortcomings associated with current IP routing schemes to be addressed. Th is article describes a software system called Routing and Traffic Engineeri ng Server (RATES) developed for MPLS traffic engineering it also describes some new routing ideas incorporated in RATES for MPLS explicit path selecti on. The RATES implementation consists of a policy and flow database, a brow ser-based interface for policy definition and entering resource provisionin g requests, and a Common Open Policy Service protocol server-client impleme ntation for communicating paths and resource information to edge routers. R ATES also uses the OSPF topology database for dynamically obtaining link st ate information. RATES can set up bandwidth-guaranteed label-switched paths (LSPs) between specified ingress-egress pairs. The path selection for LSPs is routing algorithm aimed at making the best use of network infrastructur e in an o-line environment where LSP requests arrive one by one with no a p riori information about future requests. Although developed for an MPLS app lication, the RATES implementation has many similarities in components to a n intradomain differentiated services bandwidth broker.