Research On Mobility Management In Host Identity Protocol

In the current Transmission Control Protocol / Internet Protocol(TCP/IP) stacks,the IP addresses typically serve as two roles:host identifiers and locators.From the network point of view,an IP address names the current topological location of an interface by which a host is attached to the network.That is,an IP address is used as a name for the location where a specific network interface can be found,and it is often used for the routing.From the application point of view,an IP address identifies a host. That is,an IP address is used as an identifier for the host,and it is often used for the transport layer connections.These dual roles of the IP addresses make mobility complicated. If a host moves to a new subnet and changes its IP address to a new one,all connections bound to the host will not survive,since the transport layer identifier of the connections is gone.The host then has to re-establish the connections.In order to support mobility,it is necessary to separate the identifier and the locator roles of the IP address.Host Identity Protocol(HIP) has been developed alongside the Internet Engineering Task Force(IETF) and the Internet Research Task Force(IRTF) for a few years to provide secure and continuous communications between two nodes.HIP adds a new host identity layer between the network layer and the transport layer,and introduces a new cryptography-based Host Identity Tag(HIT) to serve as the identifier for the host.Therefore,HIP decouples the transport layer from the network layer,and splits the dual roles of the IP addresses.In HIP,the transport layer connections are bound to the HITs instead of IP addresses,which become pure routing tags.Therefore, the change of the IP address is transparent to the transport layer connections,and they do not have to he broken.HIP has efficient solutions to support mobility.This dissertation studies the mobility management schemes in HIP,including the location management and handoff management schemes.The main contributions of this dissertation are shown as follows.1.This dissertation designs a new Domain Name System(DNS) resource record to translate a host domain name into an HIT and an IP address.Based on this new resource record,this dissertation then proposes a location management scheme for HIP called D-HIP.In D-HIP,the Internet is divided into some regional networks, each of which has a Rendezvous Server(RVS) managing the relationship between the HIT and the IP address of the mobile node.The DNS manages the relationship between the HIT of the mobile node and the IP address of the corresponding RVS. This dissertation also develops an analytical model to study the performance of DNS as the location manager in terms of the success rate.The performance results show that within a reasonable range,the success rate remains above 90%,thereby the DNS is a feasible solution for location management for HIP.2.In order to support micro-mobility,this dissertation proposes a dynamic hierarchical location management scheme for HIP called H-HIP.In H-HIP,the regional network is divided into some autonomous domains,and each autonomous domain is divided into some registration domains.For each registration domain,there is a local RVS managing the relationship between the HIT and the IP address of the mobile node. For each autonomous domain,there is a gateway RVS managing the relationship between the HIT of the mobile node and the IP address of the corresponding local RVS.In addition,every mobile node selects its local RVS and computes the optimal size of the registration domain according to its mobility rate and the session arrival rate,which results in the minimal signaling cost.The analytical performance results show that H-HIP outperforms D-HIP in terms of reducing the total signaling cost when the mobile node's mobility rate is higher than its session arrival rate.3.Aiming at saving the power consumption of the mobile node,this dissertation extends the paging scheme into H-HIP,and then proposes a paging-enabled location management scheme for HIP called P-HIP.P-HIP enables the mobile node to stay at the idle mode or the active mode.The idle mobile node does not have to update its IP address when it moves within the same paging area.Therefore,P-HIP can reduce the unnecessary signaling cost as well as the power consumption of the mobile node.The analytical performance results show that P-HIP outperforms H-HIP in terms of reducing the total signaling cost when the mobile node's mobility rate is higher than its session arrival rate,and the paging cost in a subnet and the ratio of the idle mobile nodes becoming active to the total mobile nodes are low.The performance results also show that P-HIP can scale well supporting large number of mobile nodes under a wide variety of system conditions.4.By introducing the HIP-enabled mobile router,this dissertation proposes an HIP-based network mobility protocol called HIPNEMO.In HIPNEMO,the mobile router provides each mobile network node with a private IP address.For each data packet sent from the mobile network node,the mobile router changes the source IP address to the mobile router's IP address.On the other hand,for each data packet destined to the mobile network node,the mobile router changes the destination IP address to the mobile network node's private IP address.In HIPNEMO,only the Il packet of the HIP Base Exchange goes through the RVS,and the mobile network node updates its IP address at the mobile router only when it moves within the same mobile network.Therefore,HIPNEMO can reduce both the location update cost and the packet delivery cost.The analytical performance results clearly show that HIPNEMO outperforms the network mobility support based on the Mobile IPv6 in terms of reducing the total signaling cost when the mobility rate is lower than the session arrival rate.5.In order to reduce the handoff latency in the handoff management scheme based on Session Initiation Protocol(SIP),this dissertation proposes a cross-layer handoff management scheme based on HIP and SIP called S-HIP.The basic idea of S-HIP is that both the mobile node and the correspondent node use their HITs to establish the session connections,and the mobile node uses the HIP update scheme instead of the SIP update scheme to update its IP address when it moves.The analytical performance results show that S-HIP outperforms SIP and hybrid SIP/Mobile IP in terms of reducing the handoff latency,the packet loss,and the handoff blocking probability. Therefore,S-HIP will support real-applications better than SIP.