Introduction to Data Communication and Networking

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• Introduction to Data Communication and Networking
• Topic 6

Protocol and Network Management
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Lecture Objectives

• Describe the OSI seven-layer reference model
• Describe TCP/IP protocols the de facto protocol
  and
• Explain the advantages of OSI seven-layer and
  TCP/IP protocols.

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Definition

• What is a protocol?
• predefined set of rules that manages and governs
  the way computers or devices communicate and
  exchange data on the network

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What is OSI 7 Layers Model?

• a standard description or "reference model" for
  how messages should be transmitted between any
  two points in a telecommunication network.
• purpose is to guide product implementers so that
  their products will consistently work with other
  products.

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• The reference model defines seven layers of
  functions that take place at each end of a
  communication.
• It is also valuable as a single reference view of
  communication that furnishes everyone a common
  ground for education and discussion.

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OSI is an OSI Standard

• OSI was officially adopted as an international
  standard by the International Organisation of
  Standards (ISO). Currently, it is Recommendation
  X.200 of the ITU-T.

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Main idea in OSI

• the process of communication between two end
  points in a telecommunication network can be
  divided into layers, with each layer adding its
  own set of special, related functions
• combination of the computer operating system,
  applications (such as your Web browser), TCP/IP
  or alternative transport and network protocols,
  and the software and hardware that enable you to
  put a signal on one of the lines attached to your
  computer.

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OSI as an analogy
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OSI in Practice
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Generic Frame Format
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Network Nodes
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OSI 7 Layers

• OSI divides telecommunications into 7 layers
  divided into 2 groups-
• -upper layer ( message passes from or to a user)
• - lower 3 layers (up to NETWORK) used when any
  message passes through host computer.

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TCP/IP

• Initially involve file transfer, e-mail, remote
  logon
• Allow the construction of very large networks
  with less central management.
• Due to automatic recovery, network problems can
  go undiagnosed and uncorrected for long periods
  of time

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The Protocol Stack

• Content, scope, size, speed and reliability of
  network varies depending on its protocols and
  implementation
• Protocols are pre-established means of
  communication

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SSL Protocol
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Network Management

• Covers-
• Security ensuring network protected from
  unauthorised users
• Performance eliminating bottlenecks in the
  network.
• Reliability availability and response time to
  malfunctions.

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Lecture Objectives
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SNMP

• a set of protocols for managing complex networks.
  
• SNMP works by sending messages, called protocol
  data units (PDUs), to different parts of a
  network.
• SNMP-compliant devices, called agents, store data
  about themselves in Management Information Bases
  (MIBs) a database of objects that can be
  monitored by a network management system.

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• The End