The Wireless Edge Router: A Network Processor-Based Packet Data Serving Node for a CDMA2000 Network

摘要

A network processing unit (NPU) is increasingly becoming the processor of choice for building custom packet-processing gateways. In this paper, we present an NPU-based design and architecture for a packet data serving node (PDSN) in a CDMA2000 network. A PDSN is a packet-processing gateway that interfaces between the Internet and the wireless radio access network to provide packet data services to mobile users. We map the different functions of the PDSN onto the packet-processing engines and the core processor of an NPU. This involves a complete separation of the control plane, which is implemented in the core processor, and the data plane, which is implemented using a multistage packet pipeline mapped onto the packet-processing engines. We describe resource allocation schemes for packet buffering and processing and also a flexible communication method with the core processor. The mechanisms described in the paper are general enough to be used to implement other NPU-based packet-processing gateways. We also present a prototype implementation of the PDSN on an NPU and show its superiority to commercial products by means of measurement experiments.