A QoS routing algorithm to support different classes of service

In order to satisfy the quality of service (QoS) requirements of the applications on Internet, the Internet Engineering Task Force (IETF) has defined two network service architectures: IntServ/RSVP (integrated service / resource reservation protocol) and DiffServ (differentiated service). Both architectures need a QoS routing mechanism and algorithm to find out an adapted route. Moreover, MPLS (multi-protocol label switching) can be used in these architectures to perform explicit routing. Based on existing routing algorithms, we propose a new pre-computed QoS routing algorithm which we call CCPF (classified minimum cost path first), which uses bandwidth as a basic metric and takes a weighted cost function as a path optimal criterion. We compare our algorithm with existing ones using simulation, and found that it can get different routes among different bandwidth-ranges to support multiple service modes. This can improve network performance.