28-06-2012, 12:30 PM
Mobile IP
mobile.ppt (Size: 175.5 KB / Downloads: 37)
We’re not quite done with IP
You’re probably sick and tired of hearing about all things IP
Forwarding, routing, multicast, etc…
One last topic we must cover because it’s going to be important in the future – mobile networking
Examples of mobile networking today?
Examples of mobile networking tomorrow?
Mobile networking should not be confused with portable networking
Portable networking requires connection to same ISP
Mobility and Standard IP Routing
IP assumes end hosts are in fixed physical locations
What happens if we move a host between networks?
IP addresses enable IP routing algorithms to get packets to the correct network
Each IP address has network part and host part
This keeps host specific information out of routers
DHCP is used to get packets to end hosts in networks
This still assumes a fixed end host
What if a user wants to roam between networks?
Mobile users don’t want to know that they are moving between networks
Why can’t mobile users change IP when running an application?
Mobile IP Entities
Mobile Node (MN)
The entity that may change its point of attachment from network to network in the Internet
Detects it has moved 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
Does this through encapsulation
Mobile IP Support Services
Agent Discovery
HA’s and FA’s broadcast their presence on each network to which they are attached
Beacon messages via ICMP Router Discovery Protocol (IRDP)
MN’s listen for advertisement and then initiate registration
Registration
When MN is away, it registers its COA with its HA
Typically through the FA with strongest signal
Registration control messages are sent via UDP to well known port
Encapsulation – just like standard IP only with COA
Decapsulation – again, just like standard IP
mobile.ppt (Size: 175.5 KB / Downloads: 37)
We’re not quite done with IP
You’re probably sick and tired of hearing about all things IP
Forwarding, routing, multicast, etc…
One last topic we must cover because it’s going to be important in the future – mobile networking
Examples of mobile networking today?
Examples of mobile networking tomorrow?
Mobile networking should not be confused with portable networking
Portable networking requires connection to same ISP
Mobility and Standard IP Routing
IP assumes end hosts are in fixed physical locations
What happens if we move a host between networks?
IP addresses enable IP routing algorithms to get packets to the correct network
Each IP address has network part and host part
This keeps host specific information out of routers
DHCP is used to get packets to end hosts in networks
This still assumes a fixed end host
What if a user wants to roam between networks?
Mobile users don’t want to know that they are moving between networks
Why can’t mobile users change IP when running an application?
Mobile IP Entities
Mobile Node (MN)
The entity that may change its point of attachment from network to network in the Internet
Detects it has moved 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
Does this through encapsulation
Mobile IP Support Services
Agent Discovery
HA’s and FA’s broadcast their presence on each network to which they are attached
Beacon messages via ICMP Router Discovery Protocol (IRDP)
MN’s listen for advertisement and then initiate registration
Registration
When MN is away, it registers its COA with its HA
Typically through the FA with strongest signal
Registration control messages are sent via UDP to well known port
Encapsulation – just like standard IP only with COA
Decapsulation – again, just like standard IP