The Internet Protocols LFTSP 1998 IS 4'3

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The Internet ProtocolsLFTSP 1998 IS 4.3

• Major Greg Phillips
• Royal Military College of Canada
• Electrical and Computer Engineering
• greg.phillips_at_rmc.ca
• 01-613-541-6000 ext. 6190

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History

• grew out of ARPA-funded networking research
  initiated in 1966 whose aim was interoperability
  between various types of computers
• original network was the ARPANET, a homogenous
  network of heterogeneous computer systems
• in early 1970s attention turned to integrating
  various different types of networks
• ultimate result was the Internet, a heterogeneous
  network of heterogeneous computer systems
• key protocols are TCP and IP
• developed in 1973 by Vint Cerf and Bob Kahn

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Internet Protocol Suite
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Internet Protocol (IP)

• a network layer protocol that contains addressing
  information and some control information that
  allows packets to be routed
• the primary Internet network layer protocol
• IP has the following two primary
  responsibilities
• it provides connectionless, best-effort delivery
  of datagrams through an internetwork.
• it provides fragmentation and reassembly of
  datagrams to support data links with different
  maximum transmission unit (MTU) sizes
• current version is IPv4 IPv6 has been
  standardised and is being implemented

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IP packet format
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IP Address Formats
Normally written in quad dot or dotted
decimal notation, e.g., 137 . 94 . 178 . 161
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IP Subnetting
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Subnet Mask Operation
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IP Routing
1
2
C
1
B
2
3
A
3
1
2a
E
F
2a
3
2a
D
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OSPF Routing
1
C
2
2
1
B
3
RU
A
1
2
1
1
Hello?
3
2
E
F
2
RU
1
2
D
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Transmission Control Protocol (TCP)

• connection-oriented
• stream data transfer
• data sent as an unstructured stream of bytes
• reliability
• acknowledgements and timeouts allows devices to
  deal with lost, delayed, duplicate, or misordered
  packets
• efficient flow control
• when sending acknowledgements back to the source,
  the receiving TCP process indicates the highest
  sequence number it can receive without
  overflowing its internal buffers
• full duplex operation
• multiplexing

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TCP Packet Format
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Connection Establishment
Initiator
Receiver
Send SYN(seqx)
Recv SYN(seqx)
Send SYN(seqy) ACK(x1)
Recv SYN (seqy) ACK(x1)
Send ACK(y1)
Recv ACK(y1)
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TCP Sliding Window

• each packet includes both
• the acknowledgement number (which byte is
  expected next), and
• the window length (how much buffer space the
  packet sender has available)
• this allows for efficient use of bandwidth

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Application Layer Protocols

• FTP. Moves files
• SNMP. Provides a mechanism for managing networks
• Telnet. Allows remote logins
• NFS, XDR. Enables file sharing
• RPC. Enables multiprocessingallows a single
  program to run on multiple computers
• X Windows. Allows graphical applications to run
  remotely
• SMTP, POP, IMAP. Enable electronic mail
• DNS. Enables distributed directory services
• HTTP. Makes the World Wide Web work.

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The Internet ProtocolsLFTSP 1998 IS 4.3

• Major Greg Phillips
• Royal Military College of Canada
• Electrical and Computer Engineering
• greg.phillips_at_rmc.ca
• 01-613-541-6000 ext. 6190