31436 Systems Software

1
31436 Systems Software NetworksAUTUMN 2002

• Chapter 2 The OSI Model

UTS Faculty of IT is a Cisco Regional Networking
Academy
2
Network Communication

• A source host is the place where the data
  originally comes from.
• The destination host is the place where the
  data is being sent to.
• Hardware/software platform independent.
• Sun UltraSPARC sending to an Apple iBook.
• Sony VAIO running Linux Mandrake sending to an
  IBM NetFinity running Windows .NET Enterprise
  Server.

3
Network media

• Copper cables
• Phone lines (56kbps dial-up, 1.5Mbps ADSL)
• CAT 5e UTP (10Base-T, 100Base-TX)
• Co-axial (512kbps/768kbps cable broadband)
• Fibre-optic cables (1000Base-TX)
• Atmosphere (wireless networking)
• 11Mbps 802.11b / 54Mbps 802.11a
• Bluetooth

4
OSI Model Why layers in OSI?

• Breaks networking task into smaller chunks.
• Easier to determine the correct network protocol
  required to connect.
• Provides a standard that networking manufacturers
  can stick to.
• Allows for platform independence.
• Simplifies understanding of networking.

5
OSI Model The Layers

• Layer 7 Application Layer
• Layer 6 Presentation Layer
• Layer 5 Session Layer Layer
• Layer 4 Transport Layer
• Layer 3 Network Layer
• Layer 2 Data Link Layer
• Layer 1 Physical Layer

6
OSI Model Mnemonic

• Application Layer Aussie
• Presentation Layer People
• Session Layer Say
• Transport Layer They
• Network Layer Never
• Data Link Layer Download
• Physical Layer Porno

7
TCP/IP Model I Why TCP/IP?

• The foundation of the Internet.
• Designed by the US Department of Defence to
  withstand nuclear war.
• Hard to destroy the Internet at its current size!
• Layer 4 Application Layer
• Layer 3 Transport Layer
• Layer 2 Internet Layer
• Layer 1 Network Access Layer

8
TCP/IP Model II Mnemonic

• Application Layer Aliens
• Transport Layer Think
• Internet Layer Im
• Network Access Layer Nice

9
OSI Model vs. TCP/IP Model

• Both are layered.
• TCP/IP has fewer layers, appears simpler.
• TCP/IP grew out of a need for a new type of
  network, OSI grew out of a need to control too
  many different network types.
• OSI is used in theory as a guide, TCP/IP is used
  in practice on the Internet.

10
Welcome to my world )

• Daniel COMARMOND
• E-Mail dacomarm_at_it.uts.edu.au
• ICQ 6606132
• Phone [phone]
• Website http//charlie.it.uts.edu.au/dacomarm
• USERNAME www
• PASSWORD rosebud
• Take care, and SMILE!!! )