1. An Enhanced Mobility Management Approach for Wireless IP Networks
Source: IEEE WCNC 2006
Authors: Jeng-Yeng Chen, Wen-Shiung Chen,
Chun-Chuan Yang, Yi-Hung Huang
and Heng-Te Chu
Speaker: Shih-Yi Lin
Date: 2006/4/26

2. Outline Introduction The MRT approach
The proposed enhanced MRT schemes
Performance evaluation
Conclusion

3. Introduction MIP (Mobile IP) MIP-RO (Mobile IP Route Optimization)
problems: triangular routing and tunneling management
MIP-RO (Mobile IP Route Optimization)
problem: difficult to enforce a binding cache on every node in the entire Internet
MRT (Mobile Routing Table)
problem: cannot demand that all routers in the Internet really support MRT

4. ﹛ The MRT approach Extend the address-mapping table used in MIP
Structure of the MRT ﹛
=0, MN in HA
=1, MN in FA
V-Flag
LET (Last Elapsed Time): the time of the last packet past through the agent

5. The proposed enhanced MRT schemes (1/7)
The proposed architecture of mobile IP with MRT (the proposed scheme1~3)

6. The proposed enhanced MRT schemes (2/7) - 1. Directed Broadcast
HA sends
ICMP address mask query to find the network mask of CN
MRT binding message to the subnet of CN via directed broadcast
If no MRT acknowledge received, there is no MRT router within the network

7. The proposed enhanced MRT schemes (3/7) - 2.Router Discovery
ICMP router discovery message
router advertisements
router solicitations
HA sends
ICMP router solicitation message to the CN network. After receiving ICMP router advertisement, he can find the default router of CN
MRT binding message to the subnet of CN via directed broadcast
If no MRT acknowledge received, HA sends SNMP query messages and combines with Reverse Path Forwarding (RPE) mechanism to find related routers

8. The proposed enhanced MRT schemes (4/7) – 3.MRT Tracking… HA R1 Rn CN
Binding update message to CN with TTL=1
ICMP Time exceed message
Binding update message
MRT acknowledgement (R1 supports MRT)
Binding update message to CN with TTL=2 …
Binding update message to CN

9. The proposed enhanced MRT schemes (5/7) – 4. ICMP Echo

10. The proposed enhanced MRT schemes (6/7) – 4. ICMP Echo
An example of payload of echo request/reply messages
Address of MN
Address of CN
Address of FA
MRT inserts its address

11. The proposed enhanced MRT schemes (7/7) – 5.Destination unreachable… CN R1 Rn HA MN
MRT binding packet with special unused port number
CN does not listen the port number
ICMP destination unreachable message with the code 3 (port unreachable) to MN
Receive ICMP destination unreachable message with the code 3
MRT binding request and update its binding table

12. Problem and enhancement
Packet blocked by router: scheme5 should work well most likely
Signaling overhead: unlikely impose serious overhead
Handoff operation
Dynamic Routing: “UpdateAll: Yes” header can update all the MRT routers within the path from CN to HA

13. Performance evaluation (1/3)
Comparison based on the transmission

14. Performance evaluation (2/3)
Comparison based on the transmission cost

15. Performance evaluation (3/3)
Additional MRT signaling overhead

16. Conclusion
Mobile IP with MRT approach is a useful scheme to avoid the triangular problem and remove the need for binding cache for each CN.