Hierarchical Routing
Content
Hierarchical Routing
Region 1
1B 1A 1C 2C 2A
Region 2
2B
2D
5B
4A
3A 5A 3B 4B 4C 5E
5C
5D
Region 3
Region 5
Region 4
2/8/2013
Hierarchical Routing
1
Full table for 1A
Dest line hops
1A 1B 1C 2A 2B 2C 2D 3A 1B 1C 1B 1B 1B 1B 1C 1 1 2 3 3 4 3
Hierarchical table for 1A
Dest Line hops
1A 1B 1C 2 3 4 5
1B 1C 1B 1C 1C 1C
1 1 2 2 3 4
3B
4A 4B 4C 5A 5B 5C 5D 5E
2/8/2013
1C
1C IC 1C 1C 1C 1B 1C 1C
2
3 4 4 4 5 5 6 5
Hierarchical Routing
2
Routing For Mobile Hosts
Users
Stationary Users
Migratory Users
Roaming Users
Mobile Users
2/8/2013
Routing for Mobile Hosts
3
Network designers View of the world
Wireless Cell
Home Agent
Mobile Host
Home LAN
Foreign Agent
WAN
Foreign LAN
MAN
2/8/2013
Routing for Mobile Hosts
4
Terminology
Areas: Small geographical units typically LAN’S or WIRELESS Foreign Agent: Keeps track of all the mobile users visiting the area. Home Agent: Keeps track of users whose home is in the area but currently visiting another area.
2/8/2013
Routing for Mobile Hosts
5
Registration Process of a Mobile User
Mobile Host Foreign Agent Home Agent
Asks for FA
Register
1 2
Contacts Examines timestamp present the in the security information
Registered/ Not
Ack to proceed/stop
1
Home address, current DLL address & security information Foreign Agents Network address & security information
Routing for Mobile Hosts
6
2 2/8/2013
Packet Routing for Mobile Users
Mobile User 3 4 Users Home Address Home Agent 2 1
Foreign Agent
1. Packet is sent to the mobile hosts home address.
2. Packet is tunneled to the foreign agent.
3. Sender is given the foreign agent’s address. 4. Subsequent packets are tunneled to the foreign agent.
2/8/2013
Routing for Mobile Hosts
7
Broadcast Routing
Sending packets to all destinations simultaneously. Various methods for broadcasting: 1. Separately addressed packets. 2. Flooding 3. Multidimensional routing. 4. Spanning tree. 5. Reverse path forwarding.
2/8/2013
Broadcast Routing
8
1. Separately Addressed Packets
Source sends a packet to each of the destination. Disadvantage:
Wastage of bandwidth. Source needs to know the complete list of destinations.
2/8/2013
Broadcast Routing
9
2. Flooding
In this technique, source sends packets on all its outgoing lines. Disadvantage:
Generates too many packets Bandwidth consumption is more.
2/8/2013
Broadcast Routing
10
3. Multi-destination routing
In this method each packet contains either a list of destinations or a bit map indicating the desired destination.
Packet arrives
R
Out going lines
2/8/2013
Broadcast Routing
11
4. Spanning Tree
A spanning tree is a subset of the subnet that includes all the routers but contains no loops.
2/8/2013
Broadcast Routing
12
8
1
12
7-8 4-5 4-3 2-1 4-7 1-3 7-6 8-6 2-4 5-6 3-5 2 3 6 8 12 12 15 16 16 19 21
3 21
2
16 4
6
3 5 15 8
12
1
12 6 3 3 5
19
6
2 4 12 15
7 2
8
16
Weighted Graph
7 2
6
8
Spanning Tree
13
2/8/2013
Broadcast Routing
Spanning Tree
Advantage: 1. Makes excellent use of bandwidth 2. Minimum number of packets are generated Disadvantage: Each router must have some knowledge of the spanning tree.
2/8/2013
Broadcast Routing
14
5. Reverse Path Forwarding
In this method, the router forwards only the packets that have traveled the shortest path from source to router, all other copies are discarded.Shortest Path
Packet is discarded
Arrival R Departure Departure Arrival Departure
2/8/2013
Packet is Forwarded
R
Not the shortest path
Broadcast Routing
15
Multicasting
A technique in which messages are sent to well defined groups which are numerically large in size but small compare to the network as a whole.
2/8/2013
Multicast Routing
16
A Subnet
1
2 1,2 2 2
Spanning tree for the leftmost 1 router 2 1,2 2 2
1,2
1,2
1
1
1
1 1 2 2 2 2
Multicast tree for group 1
2 1 1
Multicast tree for group 2 1
2
1
2/8/2013
1
Multicast Routing
1
1
17
Pruning of spanning tree
The following 2 ways can be used:
Link State Routing. Distance Vector Routing.
2/8/2013
Multicast Routing
18
Region 1
1B 1A 1C 2C 2A
Region 2
2B
2D
5B
4A
3A 5A 3B 4B 4C 5E
5C
5D
Region 3
Region 5
Region 4
2/8/2013
Hierarchical Routing
1
Full table for 1A
Dest line hops
1A 1B 1C 2A 2B 2C 2D 3A 1B 1C 1B 1B 1B 1B 1C 1 1 2 3 3 4 3
Hierarchical table for 1A
Dest Line hops
1A 1B 1C 2 3 4 5
1B 1C 1B 1C 1C 1C
1 1 2 2 3 4
3B
4A 4B 4C 5A 5B 5C 5D 5E
2/8/2013
1C
1C IC 1C 1C 1C 1B 1C 1C
2
3 4 4 4 5 5 6 5
Hierarchical Routing
2
Routing For Mobile Hosts
Users
Stationary Users
Migratory Users
Roaming Users
Mobile Users
2/8/2013
Routing for Mobile Hosts
3
Network designers View of the world
Wireless Cell
Home Agent
Mobile Host
Home LAN
Foreign Agent
WAN
Foreign LAN
MAN
2/8/2013
Routing for Mobile Hosts
4
Terminology
Areas: Small geographical units typically LAN’S or WIRELESS Foreign Agent: Keeps track of all the mobile users visiting the area. Home Agent: Keeps track of users whose home is in the area but currently visiting another area.
2/8/2013
Routing for Mobile Hosts
5
Registration Process of a Mobile User
Mobile Host Foreign Agent Home Agent
Asks for FA
Register
1 2
Contacts Examines timestamp present the in the security information
Registered/ Not
Ack to proceed/stop
1
Home address, current DLL address & security information Foreign Agents Network address & security information
Routing for Mobile Hosts
6
2 2/8/2013
Packet Routing for Mobile Users
Mobile User 3 4 Users Home Address Home Agent 2 1
Foreign Agent
1. Packet is sent to the mobile hosts home address.
2. Packet is tunneled to the foreign agent.
3. Sender is given the foreign agent’s address. 4. Subsequent packets are tunneled to the foreign agent.
2/8/2013
Routing for Mobile Hosts
7
Broadcast Routing
Sending packets to all destinations simultaneously. Various methods for broadcasting: 1. Separately addressed packets. 2. Flooding 3. Multidimensional routing. 4. Spanning tree. 5. Reverse path forwarding.
2/8/2013
Broadcast Routing
8
1. Separately Addressed Packets
Source sends a packet to each of the destination. Disadvantage:
Wastage of bandwidth. Source needs to know the complete list of destinations.
2/8/2013
Broadcast Routing
9
2. Flooding
In this technique, source sends packets on all its outgoing lines. Disadvantage:
Generates too many packets Bandwidth consumption is more.
2/8/2013
Broadcast Routing
10
3. Multi-destination routing
In this method each packet contains either a list of destinations or a bit map indicating the desired destination.
Packet arrives
R
Out going lines
2/8/2013
Broadcast Routing
11
4. Spanning Tree
A spanning tree is a subset of the subnet that includes all the routers but contains no loops.
2/8/2013
Broadcast Routing
12
8
1
12
7-8 4-5 4-3 2-1 4-7 1-3 7-6 8-6 2-4 5-6 3-5 2 3 6 8 12 12 15 16 16 19 21
3 21
2
16 4
6
3 5 15 8
12
1
12 6 3 3 5
19
6
2 4 12 15
7 2
8
16
Weighted Graph
7 2
6
8
Spanning Tree
13
2/8/2013
Broadcast Routing
Spanning Tree
Advantage: 1. Makes excellent use of bandwidth 2. Minimum number of packets are generated Disadvantage: Each router must have some knowledge of the spanning tree.
2/8/2013
Broadcast Routing
14
5. Reverse Path Forwarding
In this method, the router forwards only the packets that have traveled the shortest path from source to router, all other copies are discarded.Shortest Path
Packet is discarded
Arrival R Departure Departure Arrival Departure
2/8/2013
Packet is Forwarded
R
Not the shortest path
Broadcast Routing
15
Multicasting
A technique in which messages are sent to well defined groups which are numerically large in size but small compare to the network as a whole.
2/8/2013
Multicast Routing
16
A Subnet
1
2 1,2 2 2
Spanning tree for the leftmost 1 router 2 1,2 2 2
1,2
1,2
1
1
1
1 1 2 2 2 2
Multicast tree for group 1
2 1 1
Multicast tree for group 2 1
2
1
2/8/2013
1
Multicast Routing
1
1
17
Pruning of spanning tree
The following 2 ways can be used:
Link State Routing. Distance Vector Routing.
2/8/2013
Multicast Routing
18
