Part 3: Internet Applications The Basics of Networking, Part 3 chapter 3

Slide 3-2 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, , session access, newsgroups, file sharing,...

Slide 3-3 WWW is an Internet Application Key Point: Internet applications (HTTP, Napster, Gnutella, , 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 3-4 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 3-5 P2P is an Internet Application Key Point: Internet applications (WWW, Limewire, BitTorrent, , 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 3-6 Top P2P File Sharing Programs eDonkey Shareaza WinMX BitTorrent Limewire Morpheus eMule Ares BearShare Kazaa

Slide 3-7 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, , FTP, … are Internet Applications Next : Ch. 4: XHTML and the WWW

Slide 3-8 Web 1.0 Analogy by Philip Greenspun, photo.net. The computer is the steam engine. The network is the railroad.

Slide 3-9 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 Office 2.0 > Cloud Computing Cloud Computing > Web OS Web OS

Slide 3-10 Web 2.0 Analogy: universal virtual computer Back in 2001, Clay Shirky ( 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 3-11 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 Office 2.0 > Cloud Computing Cloud Computing > Web OS Web OS