Network fundamentals

Networking Protocols

OSI Reference Model and Devices & Protocols

• Interfaces with the end user
• Accepts requests and pass on to the presentation layer.
• Supports file transfer,network management and other services.

• The application data is either packed or unpacked.
• Protocol conversion
• Graphics expansion
• Encryption & Decryption

• Establishes, Maintains & Terminates communications between cooperating applications.

• TCP
• SPX
• ATP
• NetBIOS
• NetBEUI
• OSPF
• BGP

• Provides reliable transportation between end points.

• IP
• IPX
• X.25

• Forwarding and routing datatgrams.

• provides reliable data transfer across the physical layer.

• It defines physical and electrical characteristic of the network.

Packets

• Packet is fixed piece of information send across a network
• A Packet consists of
  • Header - It consists of addressing info, an alert signal to the receiving computer etc..
  • Data - It is the actual data
  • Trailer - Info to validate the package e.g. CRC (Cyclical Redundancy Check).

Major network protocols

• TCP/IP
  • Developed at Berkeley, California
  • This is suite of protocols some of them are
    • Transmission Control Protocol-TCP
      • TCP ensures reliable communication
      • TCP also fragments and reassemble packets.
    • Internet Protocol-IP
      • Provides addressing and routing.
      • TCP/IP v4 uses 32 bit addressing.
    • User Datagram Protocol-UDP
    • Internet Control Message protocol-ICMP
    • Address Resolution Protocol-ARP
• IPX/SPX
  • This is also a protocol suite for LAN/WAN
  • Developed by Novel Inc
  • IPX
    • Internet Package Exchange
    • Responsible for package forwarding
    • Resides in network layer of OSI/RM.
  • SPX
    • Sequential Packet Exchange.
• NetBIOS
  • Network Basic Input/Output System.
  • Resides in the session layer.
  • Nonroutable.
• NetBEUI
  • Network Basic Input/Output System Extended user interface.
  • Non routable.
  • Resides in the transport layer.
• Apple Talk
  • Used in Macintosh networks.
• Data Link Control
  • Developed by IBM.
  • Enable clients to work with Mainframes.

Related Links

Test Your Knowledge

Now it is test time. Go and try this Sample exam