CCRI J. Bernardini 1

Wireless Mobile IP

CCRI ENGR 1500

CCRI J. Bernardini 2

Mobile IP Components

MN – Mobile Node (VMD)

FA – Foreign Agent (MAP)

HA – Home Agent (MAP)

AAP – Authoritative Access Point

MAP – Mobile IP Access Point (MN)

VMD – Visiting Mobile Device (MN)

COA – Care-of-Address

HAN – Home Agent Network

FAN – Foreign Agent Network

CN – Correspondent Node

CCRI J. Bernardini 3

Subnets and Mobile IP

• Subnets provide many advantages:– make network management easier– Subnets reduce broadcasts– Subnets provide security– Subnets use subnet masks (255.255.255.0)

• WLAN subnets creates problems for roaming devices• Example:

– 192.146.118.20 /24 can seamlessly roam within 192.146.118.x /24– Note /24 is a 255.255.255.0 subnet mask– 192.146.118.20 /24 can not seamlessly roam within

202.165.200.x /24 without changing the IP address

• Mobile IP offers a solution– 192.146.118.20 can roam as a “guest” on the 202.165.200.x

network

CCRI J. Bernardini 4

Mobile IP Devices

• Visiting Device– Some APs support Mobile IP and Visiting devices

• Mobile IP Access Point– Performs all Mobile IP services

• Home Agent– Visiting devices home router– Tunnels packets from “visited” network to “visiting” device

• Authoritative Access Point (AAP)– Uses a subnet map to track all home “visiting” devices

• Foreign Agent– A router the is the attachment point for “visiting” devices– Tunnels packets to the Home Agent for the “visiting” device

CCRI J. Bernardini 5

Mobile IP Process - Discovery

1- Mobile Node (MN) gets address from Home Agent (HA)

2- MN moves to Foreign Agent (FA ) network

3- MN discovers FA or solicits for an agent.

4- MN gets Care-of-Address (COA) from FA

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Mobile IP

3-Step Process

1-Discovery

2-Registration

3-Tunneling

MN – Mobile Node

FA – Foreign Agent

HA – Home Agent

CCRI J. Bernardini 6

Mobile IP Process - Registration

5- MN send registration request to FA

6- FA checks request, adds MN to pending list

7- FA relays request to HA

8- HA checks request and creates a mobile binding

9- HA sends registration reply to FA

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Mobile IP

3-Step Process

1-Discovery

2-Registration

3-Tunneling

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10- FA checks reply and adds MN to visitor list and relays reply to MN

11-FA creates a routing entry and tunnel to HA

12- MN check reply and creates a tunnel to the HA

Through the FA

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MN – Mobile Node

FA – Foreign Agent

HA – Home Agent

CN – Correspondent Node

CCRI J. Bernardini 7

Mobile IP- Tunneling and Packet Forwarding

                                                                                                    

MN – Mobile Node

FA – Foreign Agent

HA – Home Agent

CN – Correspondent Node

COA- Care-of-Address

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13- Correspondent Node (CN) sends packet to MN and is routed to HA

14- HA intercepts packets and tunnels to the FA using the COA

15- FA relays the packets to the MN

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Mobile Node Movement