6/15/2015 Network Fundamentals IV Dr. Tim Lin ECE Department Cal Poly Pomona Add Corporate Logo Here...
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Transcript of 6/15/2015 Network Fundamentals IV Dr. Tim Lin ECE Department Cal Poly Pomona Add Corporate Logo Here...
04/18/23
Network Fundamentals IVNetwork Fundamentals IV
Dr. Tim Lin
ECE Department
Cal Poly Pomona
Add Add CorporateCorporate
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EXITEXIT>>
Agenda• What is Computer Network• ISO / OSI model• Internet Organizations• IP Addresses
– v4• Classful• Classless
– V6• IP Protocol
– Header
• ICMP Protocol• ARP Protocol
• UDP Protocol• TCP Protocol
– Header– Flow Control– Error Control– Congestion Control
• FTP Protocol• HTTP Protocol• SMTP Protocol
• Technology (LAN)
Figure 21.8 Example 21.1
220 (Service ready)
USER forouzan
LIST /usr/user/forouzan/reports
PASS xxxxxx
125 (Data connection OK)
331 (User name OK. Password?)
PORT 8888
150 (Data connection opens shortly)
230 (User login OK)
1
2
3
4
5
6
7
8
9
List of files or directories
List of files or directories
10
11
QUIT
226 (Closing data connection)
221 (Service closing)
12
13
14
DATATRANSFER
We show an example of anonymous FTP. We assume that some public data are available at internic.net.
ExampleExample 21.4
Figure 22.10 HTTP transaction
1
Request messageRequest line
Headers
Body
A blank line
2
Response message
Status line
Headers
Body
A blank line
HTTP uses ASCII characters. The following shows how a client can directly connect to a server using TELNET, which logs into port 80.
ExampleExample 22.6
Define the type of the following destination addresses: a. 4A:30:10:21:10:1A b. 47:20:1B:2E:08:EE c. FF:FF:FF:FF:FF:FF
SolutionTo find the type of the address, we need to look at the secondhexadecimal digit from the left. If it is even, the address is unicast. If it is odd, the address is multicast. If all digits are F’s, the address is broadcast. Therefore, we have the following:a. This is a unicast address because A in binary is 1010 (even).b. This is a multicast address because 7 in binary is 0111 (odd).c. This is a broadcast address because all digits are F’s.
ExampleExample 3.1
Figure 3.7 Space/time model of a collision in CSMA
Time Time
BA C D
B startsat time t1
t1
Area whereA’s signal exists
C startsat time t2
t2
Area whereB’s signal exists
Area whereboth signals exist