1. The document discusses the evolution of computer networking from isolated individual computers to interconnected networks. Early computer systems operated independently and did not share data, while later systems allowed for shared resources and interactive use among multiple users through time-sharing systems and linking computers by local networks. 2. It then describes how TCP/IP networking allowed computers from different vendors to connect over the Internet and how technologies like email and the World Wide Web became popular. TCP/IP networking uses protocols like IP to enable global interconnection across multiple private and public networks. 3. Network protocols are organized in hierarchical models like OSI to standardize functions and enable communication between different systems. Protocols define roles for each layer, with specifications describing how layers

1. 1
KUMO B4 shuya

2. 2
: TCP/IP
These Computers are isolated.
Data is not shared.
Work A Work B Work C
Alice’s PC Bob’s PC Charlie’S PC
Work A, B, C
Server

3. 3
Executing a series of jobs all at one time.
When this time Computer is very huge
and expensive, difficult to handle.
: TCP/IP
Program
(card)
Card reader
Computer
Printer
Sharing of a computing resource among
many users at same time.
It enables to interactive use of computers.
In TSS, Computers are linked by star network.
Host Computer
Each terminal access to host computer
Multiple
Terminals

4. 4
Connect computer to computer.
Before that time, data was sent in physical.
: TCP/IP
the Internet enables to connect among
multi vender.
Router
E
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h
e
r
n
e
t
Router
Router
Router
Private line
Hub
Router
E
t
h
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r
n
e
t
E
t
h
e
r
n
e
t
Mainframe
At same time, E-mail and WWW was
popular.
Telephone
Camera
Cellphone
TVPC
IP Network
WWW
Mobile Network
VoIP
iSCSI

5. 5
Connect computer to computer.
Before that time, data was sent in physical.
: TCP/IP
the Internet enables to connect among
multi vender.
Router
E
t
h
e
r
n
e
t
Router
Router
Router
Private line
Hub
Router
E
t
h
e
r
n
e
t
E
t
h
e
r
n
e
t
Mainframe
At same time, E-mail and WWW was
popular.
Telephone
Camera
Cellphone
TVPC
IP Network
WWW
Mobile Network
VoIP
iSCSI

6. 6
Protocol means rules.
Systematically summarization of protocol is called “Network Architecture”.
If we use different protocol each by each, we can’t communicate with other.
Standardize organization decide (standardize) protocol.
Ex …
Internet Engineering Task Force International Organization
for Standardization
International Telecommunication Union American National Standards Institute

7. 7
Hierarchical protocol is similar to modularization.
Dividing each functions make simplification network protocols.
OSI model is one of the most famous
layering model in computer network.
OSI model
Application Layer
Presentation Layer
Session Layer
Transport Layer
Network Layer
Data link Layer
Physical Layer
OSI model defines
“role” of each protocols.
“Protocols” defines
“role” of each layer.
“Protocols” mean promise.
The contents are “spec”.
We use products
which compliance
the “spec”.
: TCP/IP

8. 8
ConnectionType
ConnectionlessType
OK !
Send !
Before communication,
Sender and Receiver make
connection.
Sender don't confirm
receivers’ status, send packets.
Method of data delivery is separated to 2 types.
- Connection Type
- Connectionless Type
: TCP/IP

9. 9
Circuit switching
- To occupy connection path.
- Line is limited by number of switcher.
: TCP/IP
Circuit Switching
Packet Switching
Packet switching
- Connection path is shared.
- Multiple users can use same path.
- Data is split to packet and send.
Computer A
Computer B
Computer C
Computer A
Computer B
Computer C
Computer D
Computer E
Computer F
Computer D
Computer E
Computer F
Switcher A Switcher B
Switcher A
Switcher B
One line
Two line
(shared)
Buffer
(que)
2 paths, only 2 users can communicate
Path is shared, 3 users can communicate same time

10. 10
: TCP/IP
Unicast
- Sending messages to single network.
Unicast
One to one communication
Broadcast
All computer (same datalink)
Multicast
Communicate in specific group
Anycast
Communicate to specific one
Broadcast
- Sending messages to all network.
Multicast
- Sending messages to specific group.
Anycast
- Sending messages to specific one host (not intend).

11. 11
: TCP/IP
Role of address is to identify the communication partner.
This uniqueness is called “unique”
Address uniquely identify opponent.
Address hierarchy is need when address space is huge.
Address hierarchy is only in IP address (MAC address don’t have it)
Hierarchal Network