Research And Implementation Of Mobility Support Mechanism Based On LISP

In this paper,under the background of the rapid development of mobile Internet,we analyze the urgent need for mobility support in future Internet and the current weaken status of mobility support provided in network layer.Academics and industry have proposed several identity/ location separation schemes for the root cause of the current poor mobility support,namely,IP address semantic overloading.Among them,Cisco's Locator/ID Separation Protocol(LISP)is the most representative one,since it has become the IETF standard and been integrated into the Cisco routers.However,LISP is proposed to solve the problem of routing scalability,and it does not directly provide mechanisms to support arbitrary access and handover of mobile terminals.Based on the study of the running mechanism of the existing LISP-relevant mobility support scheme and comparison among the advantages and disadvantages of various schemes,we expand LISP and propose a mobility support identity / location separation architecture named LISP-MNet.LISP-MNet effectively solves the problem that LISP does not support arbitrary access and handover for mobile terminals and mobile sub-networks by introducing mobility support mechanism.It includes mapping entries storage and update mechanism and mobile registration and handover mechanism.Mapping entries storage and update mechanism in LISP-MNet,running in the core network,is designed to maintain the consistency of the mapping entries in the global system.The active notification mechanism is used to update the mapping entries stored in the mapping system.Mapping distribution mechanism based on communication chain table and active query mechanism based on timer update and synchronize the mapping entries cached in the tunnel router,with combination of passive and active way.Mobile registration and handover mechanism in LISP-MNet,running in the access network,is designed to support arbitrary access of mobile terminals and sub-networks.It provides mechanisms to support terminals access into sub-network,terminal(or sub-network)access registration,terminal(or sub-network)access keep alive,terminal(or sub-network)mobile handover.They are completely transparent to the mobile terminals.New access location are registered,updated and synchronized all by the network side instead of the modification of terminal protocol stack.Finally,we design and implement a prototype system of LISP-MNet.A series of functions and performance tests are carried out in the prototype system,such as basic communication function test,mobile handover function test,mobile video transmission test,stress test of mapping system registry item scale,and so on.The experimental results indicate that the link payload ratio of LISP-MNet is higher than that of standard LISP and LISP-MN.When the packet length is 64 bytes,the link payload rate of LISP-MNet is 1.2 times of LISP and 1.43 times of LISP-MN.The prototype system can also support arbitrary access of both mobile terminals and mobile sub-network.The actual mobile handover latency can be less than 2s.For VLC video streaming transmission,the server and the client can achieve synchronization within 2s after the client accesses into the new access network.The scale of mapping registration entries in single mapping system site can be up to 100 M,which shows the feasibility of large-scale deployment of LISP-MNet.