The Research And Design Of MPLS Forwarding Based On IXP2400 Network Processor

Based on the national 973 research project, The Obtaining and Monitoring of High Speed Network Information, in which the author has taken an active part, this paper discusses the related theories and techniques of MPLS, the hardware architecture and software development technology of IXP2400 network processor, the MPLS forwarding technology with IXP2400.At present, Both MPLS and network processor are the core technologies in high speed network. MPLS is a kind of L2/L3 integrated data transmitting technology. It takes some important expansions for IP network in packet forwarding, traffic controlling, QoS supporting. Network processor is a programmable hardware, which is an optimize design especially for the demands of network data processing. It has the ability of high speed processing. And there is no lack of high flexibility.In the architecture of MPLS networks, ingress LER receives and transmits unlabeled packets, classifying Forwarding Equivalence Class(FEC) and executing FTN(FEC to NHLFE) forwarder; LSR and egress LER receive and transmit labeled packets,executing ILM(incoming Label Map) forwarder. After researching MPLS and IXP2400, the paper puts forward a MPLS forwarding design model based on IXP2400 and describes the design scheme in detail. In particular, it analyzes how to implement the data forwarding and microcodes this part. It adopts a 6-tuple classifier for FEC, which is independent of IP Forwarding. It is comparatively easy to upgrade the traditional router. The MPLS forwarder comprises the blocks: FTN forwarder and ILM forwarder,which both support the operation of label stack and the TTL processing rules described in the RFC3443 (TTL Processing in MPLS Networks).The network processing speed of the design reachs to OC-48 (2.5Gbps). If using IXP2800 , it can implement the speed of OC-192 (10Gbps). Therefore, it can meet the requirement of network speed growing rapidly now.