COMP 101 Lecture Notes - Lecture 1: University Of Houston, Qi
Chapter 2
Application Layer
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Chapter 2: Application layer
r2.1 Principles of
network applications
r2.2 Web and HTTP
r2.3 FTP
r2.4 Electronic Mail
SMTP, POP3, IMAP
r2.5 DNS
r2.6 P2P application
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Chapter 2: Application Layer
Our goals:
rconceptual,
implementation
aspects of network
application protocols
transport-layer
service models
client-server
paradigm
peer-to-peer
paradigm
rlearn about protocols
by examining popular
application-level
protocols
HTTP
FTP
SMTP / POP3 / IMAP
DNS
rprogramming network
applications
socket API
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Document Summary
Chapter 2: application layer r 2. 1 principles of r 2. 6 p2p application network applications r 2. 2 web and http r 2. 3 ftp r 2. 4 electronic mail (cid:153) smtp, pop3, imap r 2. 5 dns. Some network apps instant messaging r e-mail r web r r remote login r p2p file sharing r multi-user network games r streaming stored video clips r voice over ip r real-time video conferencing. Application architectures r client-server r peer-to-peer (p2p) r hybrid of client-server and p2p. Pure p2p architecture r no always-on server r arbitrary end systems directly communicate peer-peer r peers are intermittently connected and change ip addresses. Instant messaging (cid:153) chatting between two users is p2p (cid:153) centralized service: client presence detection/location: user registers its ip address with central server when it comes online, user contacts central server to find ip addresses of buddies.
