The Research Of Building Safe VPDN Network In The Core Network Of China Mobile

Mobile VPN is a private network using a mobile data network,which builds a virtual private network between the users outside of enterprise-wide intranet users and the enterprise's inside network,so that users outside the corporate can access the intranet and communicate with the corporate.It focuses on large corporate customers,especially large enterprises,the Group companies.These users typically have a large group,overall business volume,many kinds of requirements such as internal communications and other kinds of business.They also requires high-quality and various kinds of service as well as flexibly controlling to their internal communications,operational modalities or expenses.Currently we set up VPN network in EPC(GPRS)core network primarily use the enterprise VPN solutions by means of GRE,the terminal by way of the PDP IP / bearer activation access to a mobile data network,the mobile data network provides accessing to enterprises data acquisition server network by establishing a GRE tunnel PGW.But GRE tunnels can have the following problems: the security of a VPN network in a way of GRE Tunnel is poor?more limited application scenarios?the users can not be flexible management by the enterprise?tunnel is opaque and unmanageable to the users and To the dispersed users,the tunnel is completely invisible,and cannot detect whether the tunnel is successfully established.In this research,In order to solve the above problems of GRE tunnel,I make a deep research on the signaling flow of the mobile core network.Through the description of "UE registration with HRPD pre-registration procedure" in 3GPP TS 36.508 version 12.9.0 Release 12,Confirm that the UE can activate and set up the bearer on the 4G network using the PPP protocol;and by setting up the experimental environment in the 4G core network,the core network SAEGW and the peer router optical fiber are directly connected to realize the VPDN Special network.Further,by using the dedicated SIM card and the dedicated APN,the VPDN service is authenticated using the dial-test method,and the L2 TP tunnel between the LAC-LNSs has been observed for more than one week,and analyzed in the core network The feasibility of building VPDN private network at the same time,summed up the use of L2 TP tunneling technology there are several points L2 TP specification is not clearly defined,but in the 4G core network using L2 TP but must be clear technical specifications: setting the SAEGW and LNS tunnel timer,SAEGW Must have the cache and SAEGW performance is not strong when the application of PPP synchronization mode;the results of the experiment not only provides 4G core network using L2 TP technology may be several common failure scenarios,which will help operators in the process of fault location,and further defined The 4G wireless network for the use of,built in the 4G core network in the VPDN network of technical specifications.Therefore,VPN network's security,flexibility and manageability for the user is a need to solve the current problems of China Mobile Group,the large enterprises.This thesis analysis by setting the SAEGW and LNS tunnel timer,SAEGW Must have the cache and SAEGW performance is not strong when the application of PPP synchronization mode to set a more secure VPDN network in the EPC(GPRS)core network,pointed out how to improve the security,flexibility and manageability of VPN network in the EPC(GPRS)core network,define the key indicators,through the use of the issue in-depth research and experimental simulation environment agreements more likely to occur,scientific guidance on how to build VPDN network EPC(GPRS)core network and configure the L2 TP tunnel which provides theoretical support for the wider use of VPDN technology in wireless core networks.