The document discusses the seven-layer OSI model and describes the four layers of the TCP/IP model. It explains that the physical layer deals with transmitting raw bits of data over a communication channel. The network layer is responsible for packetizing and routing data across multiple networks. The transport layer establishes connections between applications on different hosts, providing reliable data streams. The application layer supports protocols for common network functions such as file transfer, email, and the web.

1. 1. Syntax Format) Structure)
8
address) 8
syntax
2. Semantics
syntax
3. Timing

2. 100 Mbps
1 Mbps
7
1. physical layer)
2. data link layer)
node) 2
3. network layer)
4. transport layer)
5. session layer)
module)
6. presentation layer)

3. 7. application layer)
TCP/IP (Transmission Control Protocol/Internet
Protocol)
TCP/IP

4. real-time Voice)
data)
TCP/IP
Header
Header Encapsulat
e
Header
Demultiplexing
Encapsulation/Demultiplexing
TCP/IP 4
1. Host-to-network)
IP
2. The Internet Layer)

5. packet-switching network)
Connectionless)
Packet)
3. Transport Layer)
2
Transmission Control Protocol (TCP)
connection-
oriented) Byte stream
message
mess
age TCP
UDP
(User Datagram Protocol) connectionless)
client/server system)
request/reply)
voice)
4. Application Layer)
TELNET
FTP
SMTP

6. FTP (File Transfer Protocal)
FTP

7. FT
P USER) User Interface
FTP FTP
PI (Protocol Interpreter module)
DT (Data Transfer
module) PI DT
HTTP(Hyper Text Transport Protocol)
HTTP
end-user)
HTTPs(Hypertext Transfer Protocol
Security )
HTTP protocol
server client
Netscape 1994
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