1. Movement Detection in Mobile IPv6 JinHyeock Choi, Samsung AIT jinchoe@samsung.com 2003.07.18

2. Contents MD Overview MD Process MD Methods MD Problems MD Requirement & Further Steps

3. MD, rough sketch Internet AR1 MN AP1AP2 AR2 1. MN is attached to AR1 via AP1

4. Internet AR1 MN AP1AP2 AR2 1. MN is attached to AR1 via AP1 2. MN changes its attachment to AR2 via AP2. 3. MN receives some hint that it might have moved. 4. MN checks whether it can still reach the current Access Router, AR1 using NS/ NA exchange. 5. MN checks it can still use the current CoA using RS/ RA exchange. 6. If a MN can no longer use its current CoA, it gets another CoA and sends BU. MD, rough sketch

5. Internet AR1 MN AP1AP2 AR2 1. MN is attached to AR1 via AP1 2. MN changes its attachment to AR2 via AP2. 3. MN receives some hint that it might have moved. 4. MN checks whether it can still reach the current Access Router, AR1 using NS/ NA exchange. 5. MN checks it can still use the current CoA using RS/ RA exchange. 6. If a MN can no longer use its current CoA, it gets another CoA and sends BU. MD, rough sketch

6. MD Process Step1: Hint Step2: Checking the reachability of current AR. Step3: Checking the validity of current CoA Step4: Router Discovery with all the necessary information

7. MD methods Hint – L2 trigger – New RA message – RA beaconing Checking the reachability of current AR – NUD (3 NS probes) – One NS and timeout – RA beaconing Checking the validity of the current CoA – RS/ RA exchange – Checking whether the prefix of the current CoA is in RA. Router Discovery with all the necessary information – RS/ RA exchange

8. MD Problems The inconsistency of RA information – Link local scope of router address – Some prefix may be omitted. The delay to check the reachability of current CoA – It’s difficult to detect something is NOT there. – Roughly 3 secs for NUD Random Delay in RS/ RA exchange Erroneous detection/ Unnecessary signaling – ECS without L2 support

9. MD Requirements & further steps MD scheme requirements – Fast: low time delay – Precise/ Secure: Little error – Efficient: limit signaling (NS/NA or RS/RA) Further Step – A Basic MD scheme as a guideline for MIPv6 implementators – A Optimized MD scheme capable of seamless handoff