Distributing Mobility Agents Hierarchically under Frequent Location Updates

1
Distributing Mobility Agents Hierarchicallyunder
Frequent Location Updates

• D. Forsberg, J.T. Malinen, J.K. Malinen,
• T. Weckström, M. Tiusanen
• TSE-Institute
• Telecommunications and Software Engineering
• Laboratory of Information Processing Science
• Helsinki University of Technology
• Finland

2
Introduction

• a need to support efficient and seamless roaming
  with e.g. multimedia applications
• scaling mobility over the subnet boundaries
• independent of link-layer techniques
• real testbed, not only simulated
• testing environment for further ideas

3
Our solution

• partly distributed HA functionality
• ability to send registration replies
• tunnel updates within the organization
• private addresses may be used within the FA
  hierarchy

CN
4
Signaling

• scales to multiple levels of hierarchy
• localized registration are only sent as high in
  the hierarchy as needed
• HA's binding lifetime updated separately (forced
  registration)
• tear-down (session key reset)
• potential race condition

5
Security

• shared secret between HA and MN
• session key distribution and usage
• session key used for localized registrations
• HA as KDC
• public key encryption or shared secret between HA
  and FA organization
• local replay protection

6
Localized location update
Home Network
CN
HA
Internet
HFA1
Foreign Network
FA2
FA1
SFA
FA1
WLAN
FA5
FA3
FA6
FA4
FA4
FA3
FA4
7
Localized location update
Home Network
CN
HA
Internet
HFA1
SFA
HFA1
Foreign Network
FA2
FA1
FA2
FA2
FA1
WLAN
FA5
FA4
FA3
FA6
FA4
FA5
FA5
FA4
8
Feasible scenarios

• rapidly changing connection type (e.g.
  GPRS--WLAN)
• Need for optimized location updates
• vehicle connection
• multi-channel environment
• latency between FAs
• (e.g. radio links between access points)

9
Testbed
Home Network
HA
Organization 1, Foreign Network 1
HFA1
FA1
FA2
FA3
FA4
FA5
FA6
FA13
FA14
FA15
IEEE 802.11 WLAN
10
Testbed
Home Network
HA
Organization 1, Foreign Network 1

• wireless connection between the MN and the FAs
• Lucent's IEEE 802.11 compatible 2 Mbps WLAN
  adapters in ad hoc mode
• wired connections between mobility agents
• delay host to generate additional latency

HFA1
FA2
FA1
FA3
FA4
FA6
FA5
FA13
FA14
FA15
IEEE 802.11 WLAN
11
Testbed
Home Network
HA
Organization 1, Foreign Network 1

• two foreign networks
• a separate four node non-hierarchical
  configuration
• mobile node able to roam within and between the
  networks

HFA1
FA2
FA1
FA3
FA4
FA6
FA5
FA13
FA14
FA15
IEEE 802.11 WLAN
12
Testbed
Home Network
HA
Organization 1, Foreign Network 1

• HA HFAs Intel Pentium II and Pentium desktops
• lower FAs 486-based embedded access points
  (Martnodes)
• MN Intel Pentium II laptop
• all nodes running Linux 2.2 kernels

HFA1
FA2
FA1
FA3
FA4
FA6
FA5
FA13
FA14
FA15
IEEE 802.11 WLAN
13
Test methods

• forced location updates
• handoff latency measured in the MN
• data throughput measured with netperf
• maximum TCP throughput and paced UDP streams
  (about 1.4 Mbps)

14
Tests, Handoff times
Home Network
CN
Switch
HA
Delay host
Organization 1
HFA1
FA2
FA1
FA3
FA4
FA5
FA6
FA13
FA14
FA15
15
Tests, Handoff times
Home Network
CN
Switch
HA
Delay host
Organization 1
HFA1
FA2
FA1
FA3
FA4
FA5
FA6
FA13
FA14
FA15
16
Tests, Handoff times
Home Network
CN
Switch
HA
Delay host
Organization 1
HFA1
FA2
FA1
FA3
FA4
FA5
FA6
FA13
FA14
FA15
17
Tests, Handoff times
Home Network
CN
Switch
HA
Delay host
Organization 1
Location update latencies for some transitions
HFA1
FA2
FA1
FA1
FA2
FA3
FA4
FA5
FA6
FA3
FA4
FA13
FA14
FA15
FA13
FA14
18
Tests,TCP, no latency
19
Tests, UDP, no latency
20
Tests, TCP, 100ms lat.
21
Tests, UDP, 100ms lat.
22
Discussion

• possible to extend Mobile IP to work with
  frequent local location updates
• possible to construct deeper hierarchies
• packets lost during tunnel establishment
• can be optimized when soft handoff is used
• performance sensitive to small changes in order
  of operations

23
Conclusions

• hierarchical FA network has advantages over basic
  RFC 2002 operations
• our extensions can be useful in settings where
  latencies exist and fast mobility is required
• possibility to use private addresses

24
Distributing Mobility Agents Hierarchicallyunder
Frequent Location Updates

• D. Forsberg, J.T. Malinen, J.K. Malinen,
• T. Weckström, M. Tiusanen
• TSE-Institute
• Telecommunications and Software Engineering
• Laboratory of Information Processing Science
• Helsinki University of Technology
• Finland

25
Distributing Mobility Agents Hierarchicallyunder
Frequent Location Updates

• D. Forsberg, J.T. Malinen, J.K. Malinen,
• T. Weckström, M. Tiusanen
• Email
• dforsber, jtm, jkmaline, tweckstr,
  mikko_at_cs.hut.fi
• WWW
• http//www.cs.hut.fi/Research/Dynamics/