Transcript ch-3-FIT-pt3 - CIS Users web server

3
chapter
The Basics of Networking, Part 3
Part 3: Internet Applications
THE MEDIUM OF THE MESSAGE
> Application layer protocols: HTTP, HTTPS,
POP3, IMAP, SMTP, SSH, Telnet, FTP, P2P,
...
> Internet services that make use of these
protocols: the WWW, e-mail, session
access, newsgroups, file sharing, . . .
Slide 3-2
WWW is an Internet Application
Key Point: Internet applications (HTTP,
Napster, Gnutella, email, chat, etc.) are
implemented by special application
protocols (OSI layer 7) running on top of
the Internet protocols (TCP/IP, OSI layers
1-4).
The WWW is an Internet
Application

Slide 3-3
P2P File Sharing Networks
When most people hear the term "P2P", they think
of peer to peer file sharing over the Internet
P2P file sharing systems have become the single
most popular class of Internet applications in this
decade.
CIS 110 Technical note: A P2P network implements
search and data transfer protocols above the
Internet Protocol (layer 3)
 P2P uses special Layer 4 protocol, not TCP
Slide 3-4
P2P is an Internet Application
Key Point: Internet applications (WWW,
Limewire, BitTorrent, email, chat, . . .) are
implemented by special application protocols
(OSI layer 7) running on top of the Internet
protocols:TCP/IP (OSI layers 1-4, “Packet Layer”)

P2P networks are Internet
Applications
To access a P2P network, users simply download and
install a suitable P2P client application
Slide 3-5
Top P2P File Sharing Programs
• eDonkey
• Shareaza
• WinMX
• BitTorrent
• Limewire
• Morpheus
• eMule
• Ares
• BearShare
• Kazaa
Slide 3-6
Summary, Part 3, Internet
Applications
Key Point: Internet applications use
application protocols (OSI layer 7)
running on top of the Internet protocols
(TCP/IP, OSI layers 1-4).
 The WWW is an Internet Application
 P2P, SSH, email, FTP, … are Internet
Applications
Next: Ch. 4: XHTML and the WWW
Slide 3-7
Web 1.0 Analogy
by Philip Greenspun, photo.net.
The computer is the steam engine.
The network is the railroad.
Slide 3-8
Web 2.0 Analogy:
universal virtual computer
Tim O'Reilly is the founder/CEO of O'Reilly Media
applications revolve around the network as the
planets revolve around the Sun
universal virtual computer,
the internet as operating system.
> Office 2.0
> Cloud Computing
> Web OS
Slide 3-9
Web 2.0 Analogy:
universal virtual computer
Back in 2001, Clay Shirky (www.shirky.com) retold
the old story about Thomas J. Watson, founder of
the modern IBM. "I see no reason for more than
five of these machines in the world," Watson is
reputed to have said. "We now know that he was
wrong," Clay went on. The audience laughed
knowingly, thinking of the hundreds of millions, if
not billions, of computers deployed worldwide.
But then Clay delivered his punch line: "We now
know that he overstated the number by four."
Slide 3-10
Web 2.0 Analogy:
universal virtual computer
Tim O'Reilly is the founder/CEO of O'Reilly Media
applications revolve around the network as the
planets revolve around the Sun
universal virtual computer,
the internet as operating system.
> Office 2.0
> Cloud Computing
> Web OS
Slide 3-11