The Design And Implementation Of GGSN Gateway Used In Pocket Switch Domain Of Mobile Telecommunication Network

The communication technology is developing in a very high speed. Because core Network works as one of main parts of telecommunication network, it also develops faster. It will be a trend that all the services that core network provides will be based on IP packages. GGSN is a core equipment of mobile telecommunication network. This paper designed and realized the gateway function of GGSN in order to meet the need of design, development and test of SGSN equipment in mobile telecommunication network.On the base of deep study of the mainframe of mobile communication network, tunnel techonology, NAT technology, GTP protocal and GPRS protocal, this paper introduces the protocal stack of mobile communication network and the format of data packet, and then introduces the process that GGSN and SGSN communicate with each other in control plane and user plane. In control plane, this paper introduces the process that is used to create and maintain date path. In user plane, SGSN could communicate with other IP network by NAT technology. This paper also introduced a log management module, it could be used to record system information. In the end, I summarized the main content of the paper and offered some advice.This paper introduces an algorithm to assign IP addresses in Creating PDP context process and an algorithm to retrive assigned IP addresses in control plane. We use NAT technology to connect core network and PDN outside, adding and deleting GTP head, transform date format from one protocol to another protocol.