Threats On The GTP Protocol And The Protection Design

3G mobile communication system can provide many kinds of data services with Qos to subscribers that communicate with each other or with user access to fixed network by using mobile station anywhere and anytime. As a family member of 3G, UMTS adopts WCDMA as its radio transmission technology. In UMTS, core network is compatible with GSM.Compared with the Core Network in the GSM, GPRS/UMTS adds the PS switch. To support the PS, they add two network entities:SGSN and GGSN. GSNs communicate with each other by using GTP which can encapsulate many kinds of PDU such as IPV4, IPV6, PPP and so on. MS can access to varities of network by using GTP.GTP is critical of 3G, but has no inherent security mechanism; various attacks against GTP from air, Internet, PLMN would bring huge threat to 3G infrastructure, Internet and mobile uses. This paper analysis the GTP protocol deeply which included the VO version and V1 version. There are four kinds of threaten on the GTP protocol, and they are the GTP header threaten, the path management message threaten, the tunnel management message threaten and the location management message threaten. This paper described the scope of threaten and the protection against. To avoid these attacks, we can use the hardware firewall to analysis the GTP protocol with right security strategy. This paper designed the data strut and the flow chart of the GTP security module, each module interacted with the others. At last the paper has given the test with the example and the test result, confirms completeness which and the accuracy this kind of design function realizes.