Mobile IP and its trends for changing from IPv4 to IPv6 Nguyen Ngoc Chan*, Tran Cong Hung Ph.D. (Posts & Telecommunications Institute of Technology, Viet Nam) E-mail: ngoc_chan@ptithcm.edu.vn, conghung@ptithcm.edu.vn
Contents Introduction Delivering data in mobile IPv4 Improvement in IPv6 Deployment in MPLS network Trends of mobile IP s mechanisms Conclusion Reference Q & A
Introduction Reasons: The needs of using public resources and keeping communication The development of mobility devices Problem: How mobility devices guarantee the communication when roaming? Solutions: Each mobile node (MN) uses only one IP address at every location each MN use two addresses : home address (HA) and care-of-address (CoA)
Delivering data in mobile IPv4 Fig. 1: Implementation of Mobile IPv4.
Operations of Mobile IPv4 Three stages: Agent Discovery: In this step, MN recognizes where it is. If it is in a foreign network, its will require a new CoA. Agent Registration: MN registers its CoA to HA. HA updates its routing table and prepares for forwarding packets addressed with MN s home address (HoA) to MN. Data Delivering: CN communicate with MN via HA.
Agent Discovery (1) HA and FA broadcast or multicast Agent Advertisement Message constantly When MN moves far from HN, it tries to catch the Agent Advertisement message, compares the IP inside message, then sends to FA an Agent Solicitation Message If MN doesn t receive any Advertisement Message, it will broadcast Solicitation Message continuously to find out a Mobility Agent (HA or FA) and request the Agent to allocate to it s the Advertisement message immediately
Agent Discovery (2) Fig. 2. Agent Advertisement Message
Agent Discovery (3) Fig. 3. Agent Solicitation Message
Agent Registration (1) Home Network (2) Registration Request Message FA Foreign Network HA (1) Registration Reply Message (3) (4) MN CoA Fig. 4. CoA registration
Agent Registration (2) Fig. 5. Registration Request Message
Agent Registration (2) Fig. 6. Registration Reply Message
Data Delivering Fig. 7. Data delivering between CN and MN
Improvement in IPv6 Differences between Mobile IPv6 and Mobile IPv4 (detailed in RFC 3775) Items FA and FA s CoA Route optimization Registration Movement Detection MIPv4 Yes No Signaling message (UDP) Use Foreign Agent MIPv6 No Yes Signaling is a part of extended header Router Advertisement
MIPv6 Operation (1) HA: Stores a binding for each MN in its Binding Cache Receives, encapsulates packets with MN s CoA and returns a Binding Ack Message when it gets a Binding Update message. Accepts anycast messages and support Dynamic home agent address discovery.
MIPv6 Operation (2) MN: encapsulation and decapsulation packets Manages a Binding Update List and sends Binding Update Message to HA and CN periodically or when it receives a Binding Update Request Message Support Dynamic home agent address discovery
MIPv6 Operation (3) Mobility ability of Mobile IPv6 node is defined in extension headers of IPv6 packet Parameters of extension headersdepend on type of message (defined in Type field) Fig. 8. Extension header of Mobile IPv6 packet
Mobile IPv6 Operations (4) 4 stages: Movement detection CoA creation CoA registration Data delivering
Mobile IPv6 Operations (5) Movement detection: Home Network HoA HA Foreign Network MN MN moves to FN and receives Router Advertisement message from Foreign routers CoA MN MN compares its HoA s IP prefix with the IP received and recognizes that it stop receiving Advertisement message from HA
Mobile IPv6 Operations (6) CoA creation: MN auto-configure its address after receiving Router Advertisement message There are two methods: Stateless: MN combines IPv6-prefix it received with its MAC address to create a new IPv6 address Statefull: MN sends a CoA Request Message to the local router and then this router allocates a new IPv6 address to MN by using DHCPv6
Mobile IPv6 Operations (7) Registration: Home Network HA Foreign Network MN sends HA a binding update message to register the new CoA CoA HA updates the binding cache and sends to MN a binding acknoledgement message MN HA sends a proxy neighbor advertisement to each node in Home Network to inform that any packet sent to MN will be forwarded by HA
Mobile IPv6 Operations (8) Data delivery: Home Network Correspondence Node HA Foreign Network Two methods: CoA - Via Home Agent, using bidirectional tunnel - Directly, using route optimization MN
Mobile IPv6 Operations (9) Returning home: Home Network HoA HA Foreign Network MN When returns, MN sends a binding update messages to HA with the lifetime=0 and CoA=MN s HoA CoA MN HA updates binding cache and stoping proxy role, then sends a binding acknowledgement to MN MN informs nodes in HN that they can send packets directly to MN without passing HA
Deployment in MPLS network (1) Fig. 13. Registration procedure in single MPLS domain
Deployment in MPLS network (2) Fig. 14. Deliver datagram in a single domain.
Deployment in MPLS network (3) Fig. 15. Implementation in many MPLS domains
Deployment in MPLS network (4) Fig. 16. LSP establishment procedures for route optimization
Deployment in MPLS network (4) Fig. 17a. Binding Update procedures with QoS in case MN sets up a communication session.
Deployment in MPLS network (4) Fig. 17b. Binding Update procedures with QoS in case CN sets up a communication session.
Deployment in MPLS network (5) Fig. 18. Hierarchical tunnel establishment procedures
Trends of mobile IP s mechanisms Communication between IPv4 nodes Communication between IPv6 nodes Communication between an IPv6 node and an IPv4 node: Use Dual-stack routers Tunneling mechanism IP-in-IP encapsulation technique Mapping labels and setting up LSP Use network address translation (NAT) mechanisms Use virtual private network (VPN)
Trends (2) Fig. 19. IPv6 connections through IPv4 core network using Dual Stack routers and IP-in-IP encapsulation technique
Trends (3) Fig. 20. IPv6 connections through MPLS core network, using label mapping technique
Conclusion Mobile IPv4 and mobile IPv6 can perform separately with high performance. When co-exist, they make many troubles. Mobile IPv6 can be deployed on MPLS core network with reliable data transfer procedures. Many researches about transferring data between IPv4 nodes and IPv6 nodes rely on advanced features of MPLS. Some acceptable solutions are proposed such as using dual-stacks routers, virtual private networks (VPN) and network address translation (NAT). The next step of these researches is bringing out solutions of transferring data between mobile IPv4 nodes and mobile IPv6 nodes on MPLS core network to prepare for the replacement of IPv4 devices by IPv6 devices in future.
References [1] J. DeClercq, D. Oooms, S. Prevost, F. Le Faucheur, Connecting IPv6 Islands over IPv4 MPLS using IPv6 Provider Edge Routers (6PE), IETF Internet Draft, Work in Progress. [2] [RFC 4213] "Basic Transition Mechanisms for IPv6 Hosts and Routers, 2005. [3] [RFC 3750] Unmanaged Networks IPv6 Transition Scenarios, 2004. [4] Defeng Li, BGP-MPLS VPN extension for IPv4/IPv6 Hybrid Network, Internet Draft, 2004 [5] [RFC 3775] Mobility support in IPv6, 2004. [6] Cisco Systems, Inc, IPv6 over MPLS : IPv6 provider edge router and IPv6 VPN provider edge router, 2004. [7] Microsoft Corporation, Understanding mobile IPv6, 2004. [8] J. K. Choi, M. H. Kim, Y. J. Lee, Mobile IPv6 support in MPLS Network, Internet Draft, 2002. [9] [RFC 3344] IP Mobility support for IPv4, 2002. [10] Uyless Black, MPLS and Label Switching Networks, PTR Prentice Hall, 2002. [11] [RFC 2460] Internet Protocol, Version 6 (IPv6) Specification, 1998. [12] James D. Solomon, Mobile IP the Internet Unplugged, PTR Prentice Hall, Upper Saddle River, New Jersey, 1998. [13] Thierry Ernst, MobiWan: NS-2 extensions to study mobility in Wide-Area IPv6 Networks, Motorola Lab (http://www.inrialpes.fr/planete/mobiwan/), 2001. [14] The Network Simulator ns 2 http://www.isi.edu/nsnam/ns/
Q & A