internet technology netw 902 tutorial 6
DESCRIPTION
Mohamed Esam. Internet Technology NETW 902 Tutorial 6. Curriculum. First 3 Chapters Chapter 4: from the chapter start (page 255) up to (page 372) Chapter 5: from page 491 to 554 . Main Points for Problems. Ch’s 1&2 Till page: 200. ALOHA Slotted ALOHA CSMA/CD - PowerPoint PPT PresentationTRANSCRIPT
1
Internet TechnologyNETW 902Tutorial 6
Mohamed Esam
2
Curriculum
• First 3 Chapters • Chapter 4: from the chapter start (page
255) up to (page 372)• Chapter 5: from page 491 to 554
3
Main Points for Problems 1. ALOHA2. Slotted ALOHA3. CSMA/CD4. Token Ring, Token BUS & Ring Types. (last Tutorial)5. BUS Segments6. WLAN7. FDDI8. Spanning Tree9. Performance of (Aloha, CSMA & Token Ring)
10. SONET/SDH11. ATM12. Virtual Connections13. ISDN14. Dial up15. DSL
Ch’s 1&2Till page: 200
Ch’s 3Till page: 255
Ex.1:LAN-Inter working& Spanning TreeEx.2:MAC protocols Performance
Ex.3:IP Addressing, ATM& Access Networks
4
16.Internet Arch. & IP Addressing.17.ARP18.MTU19.Routing Functions20.Forwarding21.Routing Principles22.Distance Vector Algor.23.Link State Algor.24.Path Vector Algor.25.Routing in Internet.26.Internet Routing Protocols27.ARQ28.UDP29.TCP30.QoS
Some of Ch’s 4&5Till page: 554
Ex.4:Distance Vector &Link State Routing
Ex.5:TCP
5
ARP (Automatic Resolution Protocol)
6
In Star Network
• Switch is the responsible device in the network for ARP.• It’s done one time after connection and then updated regularly
Router Switch
PC1PC2
PC3
PC4
PC5
10.10.10.5
Internet
Send data to 10.10.10.3
Who has IP10.10.10.3, replyWith MAC Address to MAC:8AIP:10.10.10.0
My MAC is 3BMy MAC is 3B
Data
MAC IP Port
8A 10.10.10.0 _
1F 1
2A 2
3B 10.10.10.3 3
7D 4
2C 5
10.10.10.4
10.10.10.3
10.10.10.2
10.10.10.1
7
MTU (Maximum Transmission Unit)
• Sender doesn’t send larger than MTU of the used Technology.
• Routers may divide the payload into smaller data units while forwarding.
Tech. MTU
(Bytes)
IPv4 65535
Eth.2 1500
FDDI 4352
8
Dynamic Routing
Update Routing Table periodically
9
I- Distance Vector Algorithm
• Bellman Ford Algorithm.
N7
N1
N4
N5N6
N2 7
3
8
6
51
4
2
N3
Link IDLink ID
N6 is the DestinationN6 is the Destination
10
N1 N2
-1 ∞ -1 ∞
-1 ∞ -1 ∞
Link No. Distance(No. of hops)
Steps/nodes
0
1
N3 N4 N5 N6 N7
-1 ∞ -1 ∞ -1 ∞ D 0 -1 ∞
1 1 -1 ∞ 5 1 D 0 2 1
D 0
D 0
D 0
D 0
N7
N1
N4
N5N6
N2 7
3
8
6
51
4
2
N3N6 is the DestinationN6 is the Destination
Assumes whole linkshave the same cost (=1).So Total path cost = number of hops.In case of same cost select randomly.
Not Unique Solution
11
N1 N2
-1 ∞ -1 ∞
-1 ∞ -1 ∞
3 2 6 2
Link No. Distance(No. of hops)
Steps/nodes
0
1
2
N3 N4 N5 N6 N7
-1 ∞ -1 ∞ -1 ∞ D 0 -1 ∞
1 1 -1 ∞ 5 1 D 0 2 1
1 1 8 2 5 1 D 0 2 1
D 0
D 0
D 0
N7
N1
N4
N5N6
N2 7
3
8
6
51
4
2
N3
N6 is the DestinationN6 is the Destination
Shorter than (4, 2)
12
N1 N2
-1 ∞ -1 ∞
-1 ∞ -1 ∞
3 2 6 2
3 2 6 2
Steps/nodes
0
1
2
3
N3 N4 N5 N6 N7
-1 ∞ -1 ∞ -1 ∞ D 0 -1 ∞
1 1 -1 ∞ 5 1 D 0 2 1
1 1 8 2 5 1 D 0 2 1
1 1 8 2 5 1 D 0 2 1
D 0
N7
N1
N4
N5N6
N2 7
3
8
6
51
4
2
N3
N6 is the DestinationN6 is the Destination
Shorter than (4, 2)Shorter than (7,3)
13
• Repeat with All destinations Get the routing Table• N7 to All Destinations
14
• Count to infinity Problem:
15
Exerc.4 Part 1 Dynamic Routing
16
Q2-a
17
Q2-b
18
Q2-C
19
Q3-a
20
Q3-b
21
Q3-c
• Looping (Count to Infinity)
22
Q3-d
23
24
II- Link State Algorithm
1. Discover the neighbours: 2. Measure the cost to each
neighbour3. Flooding: Send Link State
packet to all routers saying the new information; includes:
• Sender ID• Packet Sequence No. (32 bits)• Packet age (TTL)• List of neighbours and
corresponding Cost.
4. Compute shortest path to all routers using Dijkstra algorithm.
Echo (Round Trip) packet
25
Part 2- Exerc.4
EA
CB 2
5
3
16
4
D
Link IDLink ID
11
11
111212
44
11
CostCost
EA
CB 2
5
3
16
4
D11
11
111212
44
11
26
A-
EA
CB 2
5
3
16
4
D11
11
111212
44
11
EA
CB 2
3
16
4
D11
11
111212
44
11
If Duplicate Messages are not avoidedIf Duplicate Messages are not avoided
27
B- Link State DatabaseFrom To Link Cost
A B 1 1
A E 5 1
B C 2 4
C D 3 1
C E 6 1
E D 4 12
EA
CB 2
5
3
16
4
D
Link IDLink ID
11
11
111212
44
11
CostCost
28
C-
• Using Time Stamps (Synchronized routers)
• Using Seq. Number:– 32 bits address to avoid Wrap around
problem.– Incremented with every new message
29
D- Apply Dijkstra
EA
CB 2
5
3
16
4
D
Link IDLink ID
11
11
111212
44
11
CostCost
Step B C D E
0 ∞ ∞ ∞ ∞
1 1/A ∞ ∞ 1/A
30
D- Apply Dijkstra
EA
CB 2
5
3
16
4
D
Link IDLink ID
11
11
111212
44
11
CostCost
Step B C D E
0 ∞ ∞ ∞ ∞
1 1/A ∞ ∞ 1/A
2 1/A* 5/B ∞ 1/A
Doesn’t Send to the Source Node (A)
31
D- Apply Dijkstra
EA
CB 2
5
3
16
4
D
Link IDLink ID
11
11
111212
44
11
CostCost
Step B C D E
0 ∞ ∞ ∞ ∞
1 1/A ∞ ∞ 1/A
2 1/A* 5/B ∞ 1/A
3 1/A* 5/B 2/E 13/E 1/A*
32
D- Apply Dijkstra
EA
CB 2
5
3
16
4
D
Link IDLink ID
11
11
111212
44
11
CostCost
Step B C D E
0 ∞ ∞ ∞ ∞
1 1/A ∞ ∞ 1/A
2 1/A* 5/B ∞ 1/A
3 1/A* 5/B 2/E 13/E 1/A*
4 1/A* 2/E* 13/E 3/C 1/A*
33
D- Node A Routing Table
Dest. Link No. Cost Next Hop
A _ 0 _
B 1 1 B
C 5 2 E
D 5 3 E
E 5 1 E