Chapter 2: Application Layer


Click here to start

Table of Contents

Chapter 2: Application Layer

Applications and application-layer protocols

Network applications: some jargon

Client-server paradigm

Application-layer protocols (cont).

What transport service does an app need?

Transport service requirements of common apps

Services provided by Internet transport protocols

Internet apps: their protocols and transport protocols

The Web: some jargon

The Web: the http protocol

The http protocol: more

http example

http example (cont.)

Non-persistent and persistent connections

http message format: request

http request message: general format

http message format: respone

http response status codes

Trying out http (client side) for yourself

User-server interaction: authentication

User-server interaction: cookies

User-server interaction: conditional GET

Web Caches (proxy server)

Why Web Caching?

ftp: the file transfer protocol

ftp: separate control, data connections

ftp commands, responses

Electronic Mail

Electronic Mail: mail servers

Electronic Mail: smtp [RFC 821]

Sample smtp interaction

try smtp interaction for yourself:

smtp: final words

Mail message format

Message format: multimedia extensions

MIME types Content-Type: type/subtype; parameters

Multipart Type

Mail access protocols

POP3 protocol

Author: Don Towsley