1. The 4x4 Approach, a MobileIP Variation An Address Mobility SolutionsAn Address Mobility Solutions Extension of MobileIPExtension of MobileIP

2. The 4x4 Approach, a MobileIP Variation Mobile IP - Concerns Mobile devicesMobile devices –Addresses assigned by region is not applicable –Device location Integration into current infrastructureIntegration into current infrastructure –Compatibility –Scalability –Transparency

3. The 4x4 Approach, a MobileIP Variation Key Terms Mobile node (MN)Mobile node (MN) –Mobile end user device/system communication with CN –Communicates with CN Correspondent node (CN)Correspondent node (CN) –Fixed (for this topic) or mobile device/system –Communicates with a MN

4. The 4x4 Approach, a MobileIP Variation Key Terms Cnt’d Foreign agent (FA)Foreign agent (FA) –Node/router MN is connected to –Boasts all network facilities Home Network (HA)Home Network (HA) –MN’s IP address belongs to this network –A router/node

5. The 4x4 Approach, a MobileIP Variation MobileIP - Background Keeps old IP addressKeeps old IP address Adds an additional addressAdds an additional address –Care of address (COA) –Two types: * Foreign agent-based (COA is FA) * Colocated (Uses Tunneling, COA is topologically correct)

6. The 4x4 Approach, a MobileIP Variation The 4x4 Approach Removes unnecessary overhead of MobileIPRemoves unnecessary overhead of MobileIP Presumes MN not dependent on FAPresumes MN not dependent on FA MN able to aquire COA from current subnetMN able to aquire COA from current subnet Optimization Goals:Optimization Goals: –Guaranteed delivery, low latency, and low overhead

7. The 4x4 Approach, a MobileIP Variation 4x4 Approach - Concepts MN-to-CN (OUT)MN-to-CN (OUT) –Four packet delivery options CN-to-MN (IN)CN-to-MN (IN) –An additional four packet delivery options Delivery selection optionsDelivery selection options –IN/OUT selection not necessarily independent –session-to-session –packet-to-packet

8. The 4x4 Approach, a MobileIP Variation 4x4 Terms s –Encapsulated source d S –Source D –Destination

9. The 4x4 Approach, a MobileIP Variation 4x4 IN packet options IN Strategy sdSDNotes Incoming Indirect Encapsulated (IN-IE) IP address of HA COA of MN IP address of CN Home IP address of MN 1. Highest overhead 2. Guaranteed Delivery 3. Uses tunneling 4. CN can be mobility unaware Incoming Direct Encapsulated (IN-DE) IP address of CN COA of MN IP address of CN Home IP address of MN 1. CN is mobility aware 2. No tunneling Incoming Uses Home Address (IN-DH)-- IP address of CN Home IP address of MN 1. No encapsulation 2. Only if intervening routers have no security constraints 3. MN & CN on common subnet Incoming Direct Uses Temporary Address (IN-DT)-- IP address of CN COA of MN 1. MN cannot receive packets sent to its original address 2. Short-term communication

10. The 4x4 Approach, a MobileIP Variation 4x4 OUT packet options IN Strategy sdSDNotes Outgoing Indirect Encapsulated (IN-IE) COA of MN IP address of HA Home IP address of MN IP address of CN 1. Highest overhead 2. Guaranteed Delivery 3. No ingress filtering 4. CN can be mobility unaware Outgoing Direct Encapsulated (IN-DE) COA of MN IP address of HA Home IP address of MN IP address of CN 1. CN is mobility aware 2. No tunneling Outgoing Uses Home Address (IN-DH)-- Home IP address of MN IP address of CN 1. No encapsulation 2. Only if intervening routers have no security constraints 3. MN & CN on common subnet Outgoing Direct Uses Temporary Address (IN-DT)-- COA of MN 1. MN cannot receive packets sent to its original address 2. Short-term communication

11. The 4x4 Approach, a MobileIP Variation Note: (1) Lighter shading indicates compatibility with current standards (2) Darker shading indicates incompatibility with current standards 4x4 Option Set

12. The 4x4 Approach, a MobileIP Variation References 1.Handout (unknown source), Wireless Internet, Ch4. Page 155 to 189. 2.Stuart Cheshire and Mary Baker, “Internet Mobility 4x4”. ACM SIGCOMM 1996, pp. 318-329, August 1996. https://www.cs.tcd.ie/~htewari/papers/InternetMobility4x4.pdf https://www.cs.tcd.ie/~htewari/papers/InternetMobility4x4.pdf 3.http://www.stanford.edu/class/cs444n/handouts/mobile1.ppt

13. The 4x4 Approach, a MobileIP Variation A Title FirstFirst –Sub-First SecondSecond –Sub-second