Download Group 10

Santhosh Rajathayalan (25764968)
Senthil Kumar Sevugan (42762375)
Cellular Networks
Cellular Technology
Architecture
Data Mobility Protocol
Authentication/Authorization
GSM/GPRS
Circuit Switched Voice,
Packet Switched Data
GPRS/Mobile IP
HLR/HSS
CDMA2000 1x-RTT
Circuit Switched Voice,
Packet Switched Data
Mobile IP
HLR/HSS
CDMA2000 1x-EV-DO
Packet Switched Data
Mobile IP
HLR/HSS
Mobile WiMAX
Packet Switched Voice
And Data
Mobile IP
AAA Server , RADIUS
CDMA 2000 Network Architecture:
WiMAX Network Architecture:
Mobile IP was developed as a means for transparently
dealing with problems of mobile users
•Enables hosts to stay connected to the Internet regardless of their
location
•Enables hosts to be tracked without needing to change their IP
address
•Requires no changes to software of non-mobile hosts/routers
•Requires addition of some infrastructure
•Requires no modifications to IP addresses or IP address format
•Supports security
Network Entities :
Mobile Node (MN)
•The entity that may change its point of attachment from
network to network in the Internet
-Detects and registers with “best” FA
•Assigned a permanent IP called its home address to which
other hosts send packets regardless of MN’s location
Since this IP doesn’t change it can be used by long-lived
applications as MN’s location changes.
Home Agent (HA)
•This is router with additional functionality
•Located on home network of MN
•Does mobility binding of MN’s IP with its COA
•Forwards packets to appropriate network when MN is away
Network Entities :
Foreign Agent (FA)
•Another router with enhanced functionality
•If MN is away from HA the it uses an FA to send/receive
data to/from HA
•Advertises itself periodically
•Forward’s MN’s registration request
•Decapsulates messages for delivery to MN.
Care-of-address (COA)
•Address which identifies MN’s current location
•Sent by FA to HA when MN attaches
•Usually the IP address of the FA
Correspondent Node (CN)
•End host to which MN is corresponding (eg. a web server)
Messages Involved:
Proxy Registration Request (PRRQ)
The Registration Request message is sent by the Proxy
Mobility Agent/MN to the Home Agent in order to set up a
mobility binding entry for a mobile device.
Proxy Registration Reply (PRRP)
The Registration Reply message is sent by the Home Agent
in response to the Proxy Registration Request received from
the Proxy Mobility Agent/MN.
Types of Mobile IP
•Client Mobile IP
•Proxy Mobile IP
RFC 5563 - WiMAX Forum / 3GPP2 Proxy
Mobile IPv4
Proxy Mobile IPv4
•Provides mobility support without "touching" these Mobile
Devices.
•Proxy Mobile IPv4 Client (PMIPv4 Client)
is responsible for initiating and maintaining the Proxy
Mobile IPv4 registration on behalf of the mobile
device.
It performs the Mobile IPv4 client function but is
hosted in the network. In some cases, this function is
collocated with the Foreign Agent(FA)
Proxy Registration During Initial Network
Attachment
Involves three stages:
•Authentication and authorization happen when the mobile
device accesses the network.
•Mobile device attempts to obtain an IP address. This triggers
Proxy Mobile IP, which assigns/authorizes the IP address.
•The mobile device configures its IP stack with the IP address and
the obtained host configuration.
Proxy Registration During Initial Network
Attachment
•Mobile device establishes a L2 (Layer 2) link with the base
station and performs access Authentication/authorization with
the AR(Access Router).
• AR contains the AAA client which exchanges AAA messages
with the AAA infrastructure to perform authentication and
authorization of the mobile device.
•The mobile device requests an IP address.
•The PMA sends a Proxy Registration Request (PRRQ) to the HA.
•The Home Agent sets up the mobility binding entry for the
mobile device after assigning an IP address
Tables maintained in the Router:
•Visitor Table
•Maintained on FA serving
an MN.
•Maps MN’s home address
to its MAC address and HA
address
•Mobility Binding Table
•Maintained on HA of MN.
•Maps MN’s Home Address
with its current CoA.
Mobile IP functionality:
•Registering the Care-of Address
•Tunneling to the Care-of Address
Proxy Registration During Mobility
• Mobile device enters into a new network and establishes a L2
(Layer 2) link with the base station and performs access
authentication/authorization with the AR(Access Router).
• The mobile device requests an IP address.
• Triggered by successful authentication, the PMA/FA sends a
PRRQ to the HA.
• The Home Agent sets up the mobility binding entry for the
mobile device with its new Care of Address(CoA).
• Now HA sends a PRRP message to New PMA , which then
creates a Tunnel to forward data.
• Because the forwarding path is established between the new
PMA and HA, the mobile device can receive or send IP packets
using the Home Address.
Registration Revocation
•Triggered by the update of the mobility binding entry for a
mobile device that has moved to a new AR.
•The HA may send a Registration Revocation to the old PMA (i.e.,
specifically to the Foreign Agent entity) in order to clean up
unused resources in an expeditious manner.
•The old PMA removes the PMIPv4 states for the mobile device.
•The old PMA sends revocation acknowledgement to the HA.
Reverse Tunneling
•In the upstream direction if MS sends packets directly to the
correspondent node, there is a mismatch.
•Now MS is in network with prefix 192.8.2. Security devices (e.g.,
firewalls) may filter out these packets since it may mark them as
illegal IP source addresses. This is to protect network to some
types of denial of service attacks.
• Reverse tunneling addresses this issue by reversing the
outgoing transmission as in the incoming route. MS sends the
packets to FA, FA tunnels them to HA, and HA removes the
tunnel and forwards the packet to the final destination.
Appearance of Being at Home Network
•Mobile Node is not aware of its mobility and does not
participate in. handover signaling.
•The network entities emulate the home network to the mobile
device attached on the network. From the mobile device’s
perspective, it operates as if it were at the home network.
•The network is directing the mobile device’s traffic to and
from its current location and will continue to do so when it
moves to a new location
Forwarding between Devices on Same PMA
•When the communication peers are both attached to the same
.
PMA.
•The traffic between them should be routed via the HA without
taking a local shortcut on the PMA.
•This ensures that data-traffic enforcement at the HA is not
bypassed.
Thank you