Lawful Interception ForMobile IP: A Mobile Agent

based Approach

- Andres Rojas

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Outline

• Generic LI model• LI in mobile telephony – GSM• Applying telephony model to MobileIP• A Mobile Agent based approach• Q?

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Generic LI model

Network

Legal Document

Operation & MaintenanceCenter

Lawful InterceptionFunction

DeliveryNetwork

Law EnforcementAgency (LEA)

Law EnforcementAgency (LEA)

Activation,Deactivation

Call Content,meta-inf

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23

4

5

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LI in Australia

• Governed by Telecommunications(Interception) Act.

• AFP, State Police, Royal Commissions• 2002-2003

– ~3700 active interceptions– Avg. ~40 day intercept period

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Outline

• Generic LI model• LI in mobile telephony – GSM• Applying telephony model to MobileIP• A Mobile Agent based approach• Q?

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LI in GSM – InterceptionActivation

Operation &MaintenanceCenter

Legal Document

ControlNetwork

LI System

MSC-A

BSC/BTS

BSC/BTS

BS

BS

BS

BS

MSC-B

BSC/BTS

BSC/BTS

BS

BS

BS

BS

1

23

Activate MSC-A

Activate MSC-B

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Outline

• Generic LI model• LI in mobile telephony – GSM• Applying telephony model to MobileIP• A Mobile Agent based approach• Q?

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Comparison of Components

500-2000*1-80No. nodes forsmall citycoverage

8 – 32 port ?2500 – 2 millionsubscribers

Capacity

Router, SwitchRow of Racks -Room

SizeMobile IPGSM (MSC)Characteristic

* Dependent on coverage area of each node

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Simulation – topology

Central InterceptionController

Leaf nodesBackbone

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Simulation – results

80.11133111

103.88172812

60.11100010

43.827299

30.785128

20.623437

12.982166

7.511255

3.85644

1.62273

0.4882

Activation time(s)

Total leaf nodesValue of n

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Simulation – movementexample

-Node and it’s-coverage area

- target- target’s movement

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Summary of Inefficiencies

• Bandwidth wasted in coverage areas ofnodes where a target does not move to

• Host resources (CPU, IO operations) wasteddue to sniffing effort

• Time to fully activate

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Outline

• Generic LI model• LI in mobile telephony – GSM• Applying telephony model to MobileIP• A Mobile Agent based approach• Q?

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Mobile Agents - Definition

• “a self contained piece of software that moveswithin the network with it’s code, state and theability to decide when to move to a new location”

• Movement– Reactive (L2, AAA)– Predictive (Liu & Maguire)

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MA based approach – operation

Operation &MaintenanceCenter

Legal Document

Network

Central LI

1

MA2

Net-A

AP

LIR

MAPMA

MN

Net-B

AP

LIR

MAPMA

MN

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4

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MA –Mobile Agent

MAP – MA Platform

LIR – LI Resource

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LI focus (1)

• Specific LI application of a more genericcase.

• Other opportunities to explore MIP & MAmarriage

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LI focus (2) – future work

• Potential for missing target’s traffic– Accuracy of prediction (predictive)– Speed of movement (reactive)

• Security !– MA is a virus– Potential for misuse could be disastrous

• How much CPU/Bandwidth is saved?

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Outline

• Generic LI model• LI in mobile telephony – GSM• Applying telephony model to MobileIP• A Mobile Agent based approach• Q?

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Q time.