Blackberry Swot Analysis
Mobile Routing in the Internet: Mobile IP
Dave Johnson
Departments of CS and ECE Rice University dbj@cs.rice.edu
David B. Johnson
The Monarch Project
Mobile Networking Architectures
Page 1
“Flat” Network Addressing
A host can move anywhere and keep the same address
But internetwork routing this way is very hard!
R1
?
R2
[2] 1
?
R3 2
David B. Johnson
The Monarch Project
Mobile Networking Architectures
Page 2
Hierarchical Network Addressing
Routers only need to know the way to each network
But if a host moves, its packets will still go to its home !
R1
Network A
[C.2] R2
Network B
B.1
R3
C.2
Network C
David B. Johnson
The Monarch Project
Mobile Networking Architectures
Page 3
IP Addressing
Originally, 3 classes of addresses:
Class A: Class B: Class C: Network Network Network Host Host Host
Can assign network number class based on expected number of hosts About two additional levels of hierarchy added to IP later through:
Subnetting : Treat some host bits as (sub)network once delivered to network
Supernetting (CIDR ): Route in backbone at each hop based on variable-length common prefix
David B. Johnson The Monarch Project Mobile Networking Architectures Page 4
Other Internetwork Addresses
Hierarchical address assignment is not unique to IP :
CLNP: Up to 20-byte, variable length, hierarchical address Novell IPX/SPX: 32-bit network number, 48-bit host number AppleTalk: 16-bit network number, 8-bit host number Banyan VINES: 32-bit network number, 16-bit host number DECnet Phase IV: 6-bit network number, 10-bit host number IPv6: 128-bit address with many levels of hierarchy
David B. Johnson
The Monarch Project
Mobile Networking Architectures
Page 5
Why Not Change Addresses?
Must notify all hosts with open connections:
Used to identify endpoints of connection Used within some transport protocols
Must also notify hosts using connectionless
Dave Johnson
Departments of CS and ECE Rice University dbj@cs.rice.edu
David B. Johnson
The Monarch Project
Mobile Networking Architectures
Page 1
“Flat” Network Addressing
A host can move anywhere and keep the same address
But internetwork routing this way is very hard!
R1
?
R2
[2] 1
?
R3 2
David B. Johnson
The Monarch Project
Mobile Networking Architectures
Page 2
Hierarchical Network Addressing
Routers only need to know the way to each network
But if a host moves, its packets will still go to its home !
R1
Network A
[C.2] R2
Network B
B.1
R3
C.2
Network C
David B. Johnson
The Monarch Project
Mobile Networking Architectures
Page 3
IP Addressing
Originally, 3 classes of addresses:
Class A: Class B: Class C: Network Network Network Host Host Host
Can assign network number class based on expected number of hosts About two additional levels of hierarchy added to IP later through:
Subnetting : Treat some host bits as (sub)network once delivered to network
Supernetting (CIDR ): Route in backbone at each hop based on variable-length common prefix
David B. Johnson The Monarch Project Mobile Networking Architectures Page 4
Other Internetwork Addresses
Hierarchical address assignment is not unique to IP :
CLNP: Up to 20-byte, variable length, hierarchical address Novell IPX/SPX: 32-bit network number, 48-bit host number AppleTalk: 16-bit network number, 8-bit host number Banyan VINES: 32-bit network number, 16-bit host number DECnet Phase IV: 6-bit network number, 10-bit host number IPv6: 128-bit address with many levels of hierarchy
David B. Johnson
The Monarch Project
Mobile Networking Architectures
Page 5
Why Not Change Addresses?
Must notify all hosts with open connections:
Used to identify endpoints of connection Used within some transport protocols
Must also notify hosts using connectionless