A
Router
IP Packet
B
IP Packet
Routing Table
NET
INT
A
1
B
2
C
3
D
4
C
D
Internet
Switch
FTP Commands
FTP Replies
Data
Connection
R3
Host 2
R1
Host 1
R7
R4
R6
R5
Source Destination Source Destination Source Destination
MAC MAC Address
MAC MAC Address MAC MAC Address
Address
Address
Address
Payload
(Data)
Link
Layer
Header
Network
Layer
Header
Transport
Layer
Header
Router
1
3
2
LAN 1
LAN 3
LAN 2
A
223.1.1.1
B
223.1.1.2
G
C
223.1.1.3
F
D
223.1.2.1
E
223.1.2.2
223.1.3.2
223.1.3.1
Method based on
simulation
Approximation
inference
Method based on
searching
Transformation
method
Information
analysing
Graph reduction
Exact inference
Combinatorial
optimization
Poly tree propagation
Start
Define Problem
Gather Facts
Finished
Consider Possibilities
Document Facts
Create Action Plan
Problem Resolved
Implement Action Plan
Observe Results
Utilize Process
yes
Do problem
symptoms
stops?
no