TeleMIP: Telecommunications-enhanced
Mobile IP
Archan Misra
archan@research.telcordia.com
Applied Research,
Telcordia Technologies
An SAIC Company
TeleMIP Contributors/Goals
Telcordia Technologies
University of Texas
at Arlington





Sajal K Das
Archan Misra
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 – 2
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 – 3
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 – 4
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 interdomain 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 – 5
TeleMIP’s Architecture Layout
IPCN2000 – 6
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 – 7
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 – 8
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 – 9
Initial Domain-Based Registration
Procedure
IPCN2000 – 10
Subsequent Intra-Domain Registration
IPCN2000 – 11
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 – 12
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 – 13
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 – 14
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 reestablishment 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 – 15
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 – 16
Feature Comparison of Alternative Protocols
Desired
Mobility
Feature
Requires
Minimal
Changes to
Domain Nodes
Efficient
Address
Utilization
Separate
Security for
Intra-Domain
and Global
Mobility
Reduces IntraDomain Update
Latency
Cellular
IP
HAWAII
HMIP
(v6)
TeleMIP
2
Mobile IP
Regional
Tunnel
4
2
1
4
5
2
5
5
5
-
-
3
4
5
3
3
4/5 (*)
4
5
5 (Most Favorable) -- 1(Least Favorable)
IPCN2000 – 17
Comparison of Alternative Protocols…2
Desired
Mobility
Feature
Reduces Global
Update
Frequency
Reduces Local
Update
Frequency
Low
Encapsulation
and Transport
Overhead
Can Work
without changes
to CN
Cellular
IP
HAWAII
HMIP
(v6)
TeleMIP
5
Mobile IP
Regional
Tunnel
5
5
5
5
5
3
3
3
3
4
4
2
5
2
5
5
5
2
5
IPCN2000 – 18
Comparison of Alternative Protocols…3
Desired
Mobility
Feature
Scalable IntraDomain
Routing
Well-defined
for Arbitrary
and MultiPeered
Networks
Multiple Agents
for Dynamic
Load Balancing
Supports Colocated Address
Mode
Cellular
IP
HAWAII
HMIP
(v6)
TeleMIP
3
Mobile IP
Regional
Tunnel
5
3
5
5
1
1
5
5
5
2
2
4 (?)
4
5

5
3
5
5
IPCN2000 – 19
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 2000.
 Develop a Web page to retrieve papers/ implementations etc.
IPCN2000 – 20
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 – 21
That’s It for Now…..
 For more information, please contact
– archan@research.telcordia.com
– subir@research.telcordia.com
IPCN2000 – 22
References
 RFC 2002, IETF. “IP Mobility Support”
 A Campbell, J Gomez, C-Y Wan, Z Turanyi and A. Valko, “Cellular IP”, <draft-valkocellularip-01.txt>, Work in Progress, October 1999.
 E. Gustafson, A Jonsson, C. Perkins, “Mobile IP Regional Registration”, draft-ietfmobileip-reg-tunnel-02.txt”, Work in Progress, March 2000.
 R. Ramjee, T. La Porta, S. Thuel, K Varadhan and L. Salgarelli, “IP Micro-Mobility
using HAWAII”, <draft-ietf-mobileip-hawaii-00.txt>, Work in Progress, June 1999.
 F. Vakil, A. Dutta, J.-C. Chen, S. Baba, and Y. Shobatake, “Host Mobility Management
Protocol: Extending SIP to 3G-IP Networks”, <draft-itsumo-hmmp-00.txt>, Work in
Progress, October 1999.
 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 2000.
 K Malki and H Soliman, “Hierarchical Mobile IPv4/v6 and Fast Handoffs”, <draftelmaki-soliman-hmipv4v6-00.txt>, Work in Progress, March 2000.
 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-solimanhmipv4v6-00.txt”, Woek in Progress, March 2000.
IPCN2000 – 23