4x4 Optimization Alkesh Patel & Hemant Patel

Background IP address – identify computer on the network Mobile domain - mobile host IP address is not restricted to region IP address is not restricted to region Problem : Identifying computer on mobile domain Solution: Change IP address when the host moves to other subnet Change IP address when the host moves to other subnet Use same IP address and add special routing entries to track the current location of the user – good for small group Use same IP address and add special routing entries to track the current location of the user – good for small group

Challenge Following challenges should be solved before considering solution Compatibility: Should work with current wired internet infrastructure Compatibility: Should work with current wired internet infrastructure Scalability: Should be able to support large number of user to meet future demands Scalability: Should be able to support large number of user to meet future demands Transparency: User should not feel difference between wireless and wired network Transparency: User should not feel difference between wireless and wired network

Optimization Optimization scheme should ensure Guaranteed delivery Guaranteed delivery Low latency Low latency Low overhead Low overhead

4x4 Approach Four options for packets direction IN approaches CN to MN IN approaches CN to MN OUT approaches MN to CN OUT approaches MN to CN s – outer source in the encapsulated packet s – outer source in the encapsulated packet d – outer destination in the encapsulated packet d – outer destination in the encapsulated packet S – inner source of the packet S – inner source of the packet D – inner destination of the packet D – inner destination of the packet

The IN strategies in 4x4 approach IN Strategy sdSDNotes Acceptable Combinations Incoming Indirect Encapsulated (IN-IE) IP address of HA COA of the MN IP address of the CN Home IP address of the MN 1. Highest overhead 2. Guaranteed delivery Uses tunneling CN need not be mobility aware OUT-IE OUT-DE OUT-DH Incoming Direct Encapsulated (IN-DE) IP address of CN COA of the MN IP address of the CN Home IP address of the MN 1. CN is mobility aware 2. No tunneling OUT-DE OUT-DH Incoming Uses Home Address (IN-DH) Not applicable IP address of the CN Home IP address of the MN 1. No encapsulation 2. Usable when there are no security constraints at intervening routers 3. MN and CN on same subnet OUT-DH only Incoming Direct Uses Temporary address (IN-DT) Not applicable IP address of the CN COA of MN 1. MN cannot receive packets addressd to its orginal IP address 2. Useful for short-term communication OUT-DT only

The OUT strategies in 4x4 approach OUT StrategysdSDNotesAcceptable Combinations Outgoing Indirect Encapsulated (OUT-IE) COA of the MN IP address of HA Home IP address of the MN IP address of the CN 1. Highest overhead 2. Guaranteed delivery 3. No ingress filtering 4. CN need not be mobility aware IN-IE only Outging Direct Encapsulated (OUT-DE) COA of the MN IP address of CN Home IP address of the MN IP address of the CN 1. CB is mobility aware 2. No tunneling IN-IE IN-DE Outgoing Direct Home Address (OUT-DH) Not Applicable Home IP address of the MN IP address of the CN 1. No encapsulation 2. Usable when there are no security constrains at the interven- ing routers 3. MN and CN on the same subject IN-IE IN-DE IN-DH Outgoing Direct uses Termporary Address (OUT-DT) Not Applicable COA of MNIP address of the CN 1. MN cannot receiver packets addressed to its original IP address 2. Useful for short- term communication IN-DT only

Comparison & Evaluation 16 different strategies for transmission Four approaches for each of the two directions Four approaches for each of the two directions Different advantages & disadvantages Different advantages & disadvantages Choice based on session basis or packet-to-packet basis