Ch ng 2 (ti p).ươ ế
Giao th c t ng ng d ng (application layer)ứ ầ ứ ụ
Đoàn Th Thu Hàị
Chapter 2. The Application Layer 2
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Discussion
Web programming with ASP.
Visual Basic programming.
Object oriented programming.
Event driven programming.
Component driven programming.
TCP Socket programming.
Simple web server.
Chapter 2. The Application Layer 3
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Ch2. The Application Layer
2.1. M t s khái ni m và nguyên t c.ộ ố ệ ắ
2.2. Web & Hyper Text Transfer Protocol.
2.3. Web design and HTTP, Web programming.
2.4. File Transfer Protocol.
2.5. Electronic Mail Protocols.
2.6. Domain Name System.
Chapter 2. The Application Layer 4
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2.4. FTP - File Transfer Protocol
Truy n/t i t p (to/from remote host).ề ả ệ
Client/server model
Client: đa ra yêu c u truy n t i.ư ầ ề ả
Server = remote host.
FTP: RFC 959
file transfer FTP
server
FTP
user
interface
FTP
client
local file
system
remote file
system
user
at host
Chapter 2. The Application Layer 5
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FTP: control & data connections
FTP s d ng TCP.ử ụ
FTP s d ng đng th i 2 liên k t TCP t i 2 c ng:ử ụ ồ ờ ế ạ ổ
TCP control connection, port 21: trao đi các thông đi p đi u ổ ệ ề
khi n (commands, responses…).ể
TCP data connection, port 20: truy n t i t p.ề ả ệ
FTP l u gi tr ng thái client trong phiên làm vi c (state ư ữ ạ ệ
vs. HTTP is stateless).
FTP
client
FTP
server
TCP control connection
port 21
TCP data connection
port 20