An SAIC Company TeleMIP: Telecommunications-enhanced Mobile IP Archan Misra Applied Research, Telcordia Technologies

IPCN2000 – 2 TeleMIP Contributors/Goals Telcordia TechnologiesUniversity of Texas at Arlington  Archan MisraSajal K Das  Subir Das  Ashutosh Dutta  Anthony Mcauley  Prathima Agrawal Goals –Develop an IP-based mobility architecture for 3rd/4th generation cellular networks that is not tied to a single protocol. –Apply general ideas for mobility management in hierarchical dynamic networks.

IPCN2000 – 3 TeleMIP: Telecommunications-enhanced Mobile IP Goal: Improve the latency of intra-domain location updates. Technique A two-level mobility management solution for intra-domain mobility.  Currently based on extensions/modifications to Mobile IP functionality. –However, two-level architecture is independent of the exact mobility management algorithm (Mobile IP, SIP).

IPCN2000 – 4 Primary Problems with Basic Mobile IP  High latency of location updates –All location updates must travel all the way to Home Agent (HA) or Correspondent Node (CN).  High frequency of global location update messages –Since address binding changes with change in every subnet, frequent generation of location updates to HA/CN.  Inefficient use of existing public address space –Since HA (or CN) use the mobile’s current care-of address, we need at least one global address per subnet (for FA) or one global address per mobile in FA (in co-located mode).

IPCN2000 – 5 TeleMIP’s Solution to Problems  Reduce the latency of intra-domain location updates by specifying an intra-domain termination point (Mobility Agent or MA). –Intra-domain updates only up to the MA, which provides a globally valid COA to MN.  Reduce the frequency of global update messages –Since the MA is located at a higher hierarchy than that of subnets, global updates (to HA, CNs etc.) only occur for inter- domain mobility.  Reduce the requirement of public addresses –By promoting a two-level addressing scheme, we promote the use of private (locally-scoped) addresses for handling intra-domain mobility.

IPCN2000 – 6 TeleMIP’s Architecture Layout

IPCN2000 – 7 Architecture Functional Specification  Foreign Agents/ DHCP(DRCP) Servers at the subnet level –Provide MN with a locally-scoped address which identifies mobile location within the domain.  Mobility Agents (MA) distributed within the domain –Multiple MAs for load-balancing and redundancy within the domain. –Provides MN with a global care-of address that stays constant within the domain. MN’s location is globally known only up to the MA-level granularity.  HA/CNs as in conventional Mobile IP (with or without route optimization).

IPCN2000 – 8 TeleMIP Operational Overview: 1  Network is divided into domains.  Domain Identifiers broadcast in Agent Advertisement/ Discovery messages.  When MN first moves into a domain, it obtains a global care-of address (Mobility Agent’s (MA) address), as well as a local care-of address. –MA’s global COA sent in the registration message to HA.  In IPv4 optimized mode, HA transmits this global COA to CNs in its binding updates; in IPv6, MN sends the global COA directly to CNs in binding updates. –MN also registers itself (with its local COA) with its MA.

IPCN2000 – 9 TeleMIP Operational Overview: 2  MN retains the same MA (global care-of address) within the same domain  All packets from the global Internet tunneled to the MA, which acts as a single point of enforcement/accounting. –MA forwards packets to MN, using regular IP routing, by using the local COA (co-located or FA) as the destination.  On subsequent movement within the domain, MN only obtains a new local COA. –No need to update the HA or CNs. –MN updates its MA with its new local COA.

IPCN2000 – 10 Initial Domain-Based Registration Procedure

IPCN2000 – 11 Subsequent Intra-Domain Registration

IPCN2000 – 12 Architectural Choices in TeleMIP…1 Two-level Mobility Management  Judged to be an adequate compromise between the need for fast intra-domain location updates and low network management complexity. –Single level suffers from the generation of frequent global messages and large update latencies. (common to Mobile IP and SIP-based mobility management) –Multiple levels (HMIP etc.) introduce additional management (especially security) overhead as well as generate multiple points of failure.

IPCN2000 – 13 Architectural Choices in TeleMIP…2 A Domain-Specific Agent for Handling Intra-domain Mobility  MA provides a stable care-of address, as well as a central point for regulating and metering the traffic flow.  Stable care-of address also promotes proper functioning of TCP applications and the establishment of backbone QoS bounds (up to the MA).  Architecture allows flexibility in the choice of either FA-based or co-located local care-of addresses. Thus, traffic sent by MN can proceed directly.  In-bound traffic must arrive via MA. Architecture provides a point (in the wired backbone) to filter traffic before it reaches the expensive wireless link. MA also serves as a natural point for performing local AAA registration.

IPCN2000 – 14 Architectural Choices in TeleMIP…3 Global Location Updates are Responsibility of the Mobile Node  By shifting the responsibility of global updates to the MN, we allow the destination of the update message to be a specific node (HA or SIP server) or correspondent nodes (SIP, Mobile IPv6).  Separates the local security and authentication scheme (between MN, HA and FA) from global security and authentication (between MN and HA or between MN and CN).

IPCN2000 – 15 Architectural Choices in TeleMIP…4 Cellular Domain Nodes Left Unchanged as far as Possible  Avoid requiring host-based routing or protocol upgrades at all nodes. –Use conventional routing algorithms to avoid upgrades at large number of nodes. –In addition to scaling concerns (which may be important only in the future), host-based routing leads to high route re- establishment costs in case of intermediate node failures.  Use of explicit locally-scoped address promotes address efficiency and reduces the need for host-specific route management.

IPCN2000 – 16 Possible Alternatives for Intra-Domain Mobility  Certainly, TeleMIP shares many of its ideas with several other proposals, including: –Cellular IP (Ericsson, Columbia University) –HAWAII (Lucent Technologies) –Mobile IP Regional Tunnel Management (Ericsson, Nokia)+ Hierarchical Mobile IP with Fast Handoffs (Ericsson) –HMMP (Telcordia, Toshiba) –HMIPv6 (INRIA)

IPCN2000 – 17 Feature Comparison of Alternative Protocols 5 (Most Favorable) -- 1(Least Favorable )

IPCN2000 – 18 Comparison of Alternative Protocols…2

IPCN2000 – 19 Comparison of Alternative Protocols…3

IPCN2000 – 20 Status of TeleMIP  Prototype Linux code to be ready by end-July. –Use and augment existing publicly available IPv4 code. –Changes involve Agent Advertisements, two care-of-addresses and small changes to FA (MA) code.  S. Das, A. Misra, P. Agrawal and S. Das, “TeleMIP: Telecommunication Enhanced Mobile IP architecture for Fast Intra-Domain Mobility”, to be published in IEEE PCS Magazine, August  Develop a Web page to retrieve papers/ implementations etc.

IPCN2000 – 21 Additional Features of TeleMIP  Techniques for faster intra-domain handoffs have been developed.  Enhancements to architecture to incorporate QoS considerations inside the mobility management scheme are under consideration.  Specific attention to the security and authentication mechanisms of TeleMIP is the next goal.

IPCN2000 – 22 That’s It for Now…..  For more information, please contact

IPCN2000 – 23 References  RFC 2002, IETF. “IP Mobility Support”  A Campbell, J Gomez, C-Y Wan, Z Turanyi and A. Valko, “Cellular IP”,, Work in Progress, October  E. Gustafson, A Jonsson, C. Perkins, “Mobile IP Regional Registration”, draft-ietf- mobileip-reg-tunnel-02.txt”, Work in Progress, March  R. Ramjee, T. La Porta, S. Thuel, K Varadhan and L. Salgarelli, “IP Micro-Mobility using HAWAII”,, Work in Progress, June  F. Vakil, A. Dutta, J.-C. Chen, S. Baba, and Y. Shobatake, “Host Mobility Management Protocol: Extending SIP to 3G-IP Networks”,, Work in Progress, October  S. Das, A. Misra, P. Agrawal and S. Das, “TeleMIP: Telecommunication Enhanced Mobile IP architecture for Fast Intra-Domain Mobility”, to be published in IEEE PCS Magazine, June  K Malki and H Soliman, “Hierarchical Mobile IPv4/v6 and Fast Handoffs”,, Work in Progress, March  M. Handley, H. Schulzrinne, E. Schooler, J. Rosenberg, “SIP: Session Initiation Protocol, RFC 2543 (Proposed Standard), IETF  E. Wedlund, and H. Schulzrinne, “Mobility Support using SIP” ACM WOWMOM workshop, Seattle, August 1999  K. el Malki and H Soliman, “Hierarchical Mobile IPv4/v6 and Fast Handoffs”, <draft-elmalki-soliman- hmipv4v6-00.txt”, Woek in Progress, March 2000.