This presentation will demonstrate the fundamentals of Computer Networks

1. Computer Networking
Fundamentals
By,
Uma

2. Module - 1
Basic
Internetworking

3. What is Networks?
 Networks - Link computers together to share files and
communicate and do all the things we like to do.
 Networks range in size from the smallest and simplest
network—two computers connected together—to the largest
and most complex network of all—the Internet.

4. Network Types - Local Area Network

5. Wide Area Network

6. Architecture of Networks
 Client/Server
 Peer to Peer
 Mainframe/Terminal

7. Servers and Clients

8. Peer-to-Peer Network

9. MainFrame/Terminal

10. ConnectionOriented Communication

11. Connectionless Communication

12. Module - 2
OSI Reference Model

13. OSI Layers

14. TCP/IP Model

15. Application Layer
 Purpose
 User application to network service interface
 Examples
 FTP
 E-mail services – POP3,SMTP
 HTTP
 Telnet

16. Functions of Application Layer
 Identifies communication partners
 Determines resource availability
 Synchronizes communication

17. Presentation Layer
 Purpose
 Formats data for exchange between points of
communication
 Example:
 Redirector software
 Formats for transmission to the server

18. Functions of Presentation Layer
 Protocol conversion
 Data translation
 Encryption
 Character set conversion
 Expansion of graphics command

19. Session Layer
 Purpose
 Oversee a communication session
Establish
Maintain
Terminate

20. Functions of Session Layer
 Performs name recognition and related security
 Synchronization between sender and receiver
 Assignment of time for transmission
 Start time
 End time etc.

21. Transport Layer
 Purpose
 Repackage proper and efficient delivery of
packages
Error free
In sequence
Without duplication

22. Functions of Transport Layer
 For sending data
 Repackage the message to fit into packets
Split long messages
Assemble small messages
 On receiving data
 Perform the reverse
 Send an acknowledgment to the sender
 Solve packet problems
 During transmission and reception

23. Network Layer
 Purpose
 Addressing and routing the packets
 Example application at the router
 If the packet size is large, splits into small
packets

24. Functions of Network Layer
 Address messages
 Address translation from logical to physical
 Ex: nganesa ----------> 102.13.345.25
 Routing of data
 Based on priority
 Best path at the time of transmission
 Congestion control

25. Data Link Layer
 Purpose
 Manages the flow of data over the physical
media
 Responsible for error-free transmission over the physical
media
 Assures error-free data submission to the Network Layer

26. Datalink Layer Functions
 Point of origin
 Packages data for transmission over physical line
 Receiving end
 Packages data for submission to the network layer
 Deals with network transmission protocols
 IEEE 802. protocols

27. Datalink Layer Subdivision
 Logical Link Control (LLC) sub-layer
 Manages service access points (logical link)
 Error and flow control
 Media Access Control (MAC) sub-layer
 Applies directly to network card
communication
 Access control

28. Physical Layer
 Purpose
 Deals with the transmission of 0s and 1s over
the physical media
Translation of bits into signals
 Example
 Pulse duration determination
 Transmission synchronization

29. Functions of Physical Layer
 Encode bits into signals
 Carry data from the h higher layers
 Define the interface to the card
 Electrical
 Mechanical
 Functional
 Example: Pin count on the connector

30. Module - 3
Ethernet
Technologies

31. Ethernet Cabling Types
 Coaxial cabling
Thinnet
Thicknet
 Twisted-pair cabling
Cat 3
Cat 5
Cat 5e
Cat 6
 Fiber optic cabling
Single mode and Multi mode

32. Ethernet - RJ45

33. Types of Ethernets
 10BaseT – runs at 10Mbps
 100BaseT – runs at 100Mbps – Fast Ethernet
 1000BaseT – runs at 1000Mbps or 1Gbps – Gigabit
Ethernet
 10000BaseT – runs at 10000Mbps or 10Gbps Ethernet

34. Module - 4
Hubs,Switches and
Routers

35. Network Device Icons

36. Layer 1 Hubs
 no intelligent forwarding whatsoever
 hubs will always forward every frame out every port
 operate at half-duplex, which allows a device to either
transmit or receive data, but not simultaneously
 Ethernet utilizes Carrier Sense Multiple Access with Collision
Detect (CSMA/CD) to control media access.

37. Layer 2 Switches
 Layer-2 devices build hardware address tables, which will
contain the following at a minimum:
 Hardware addresses for host devices
 The port each hardware address is associated
with
 intelligent forwarding decisions based on frame (Data-Link)
headers.
 Can operate in full duplex.