Network Protocols and ns2

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Network Protocols and ns2
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User Datagram Protocol UDP 1

• http//www.faqs.org/rfcs/rfc768.html
• datagram mode
• packet-switched computer communication
• interconnected set of computer networks
• Internet Protocol (IP) is used as the underlying
  protocol
• application programs to send messages to other
  programs
• minimum protocol mechanism

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User Datagram Protocol UDP 2

• Transaction oriented
• Delivery and duplicate protection are not
  guaranteed
• Applications requiring ordered reliable delivery
  of streams of data should use the Transmission
  Control Protocol (TCP)
• Send and forget

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Transmission Control Protocol 1

• http//www.faqs.org/rfcs/rfc793.html
• The Transmission Control Protocol (TCP) is
  intended for use as a highly reliable
  host-to-host protocol between hosts in
  packet-switched computer communication networks,
  and in interconnected systems of such networks.

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Transmission Control Protocol 2

• Reliable received data is acknowledged
• Flow control mechanisms to avoid congestion
• TCP assumes it can obtain a simple, potentially
  unreliable datagram service from the lower level
  protocols
• Provides a way for the TCP to send and receive
  variable-length segments of information enclosed
  in internet datagram "envelopes".

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Constant Bit Rate CBR Traffic

• CBR may be used in video links
• Congestion causes some packets to be dropped
• Lost packets are not retransmitted
• Video QoS influenced by number of dropped packets
• CBR service may run on top of UDP

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Constant Bit Rate CBR Traffic

• Smallwood - An Introduction to ATM
• Computing and Control Eng Journal
• Oct 1998 p 240
• Continuous isochronous stream of data traffic of
  video of broadcast quality and voice
• Expensive option
• Guaranteed bandwidth even when idle

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File Transfer Protocol FTP

• http//www.faqs.org/faqs/ftp-list/faq/
• Allows a person to transfer files between two
  computers
• WSFTP is a client application
• FTP runs over TCP/IP
• FTPD provides a server function
• D deamon or quite servant
• FTP upload and download

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File Transfer Protocol FTP

• Console level programs
• Window based programs