1. Introduction To Networking

2. Overview of LAN,MAN,WAN

3. LAN A local-area network (LAN) is a computer network that spans a
relatively small area(100mtr). Most LANs are confined to a single
building or group of buildings, however, one LAN can be connected
to other LANs over any distance via telephone lines and radio
waves. A system of LANs connected in this way is called wide area
network(WAN)

4. Types of LANs The three most popular types of LANs are:
Token ring network
FDDI (Fiber Distributed Data Interface) network
Ethernet

5. Token Ring Network Originally developed by IBM in 1970’s
Still IBM’s primary LAN technology
In cases of heavy traffic, the token ring network has higher throughput than Ethernet due to the deterministic (non- random) nature of the medium access
Is used in applications in which delay when sending data must be predictable
Is a robust network i.e. it is fault tolerant through fault management mechanisms
Can support data rates of around 16 Mbps
Typically uses twisted pair

6. FDDI (Fiber Distributed Data Interface)
FDDI is a standard developed by the American National Standards Institute (ANSI) for transmitting data on optical fibers
Supports transmission rates of up to 200 Mbps
Uses a dual ring
First ring used to carry data at 100 Mbps
Second ring used for primary backup in case first ring fails
If no backup is needed, second ring can also carry data, increasing the data rate up to 200 Mbps
Supports up to 1000 nodes
Has a range of up to 200 km
Source:

7. Ethernet First network to provide CSMA/CD
Developed in 1976 by Xerox PARC (Palo Alto Research Center) in cooperation with DEC and Intel
Is a fast and reliable network solution
One of the most widely implemented LAN standards
Can support data rates in the range of 10Mbps- 10 Gbps
Used with a bus or star topology

8. Metropolitan area network
A Metropolitan Area Network (MAN) is a network that is utilized across multiple buildings
Commonly used in school campuses or large companies with multiple buildings
Is larger than a LAN, but smaller than a WAN
Is also used to mean the interconnection of several LANs by bridging them together. This sort of network is also referred to as a campus network

9. Wide area network
A Wide Area Network is a network spanning a large geographical area of around several hundred miles to across the globe
May be privately owned or leased
Also called “enterprise networks” if they are privately owned by a large company
It can be leased through one or several carriers (ISPs-Internet Service Providers) such as AT&T, Sprint, Cable and Wireless
Can be connected through cable, fiber or satellite
Is typically slower and less reliable than a LAN
Services include internet, frame relay, ATM (Asynchronous Transfer Mode)

10. Example of WAN application
Sprint
Network LA
Runs a 100 Mbps LAN
Sprint provisions a connection between the two networks DC
Runs a 1Gbps LAN

11. Network Interconnection Components
Networks can be connected to each other through several components
Repeater
Bridge
Router
Gateway
Before explaining the above components, we need to understand the OSI model

12. Overview of Network Topologies

13. Network Topologies
Network Topology – Maps of how the physical or logical paths of network devices connect. The three major topologies are star, ring, and bus.
Star Topology – Most common Ethernet network topology where each device connects to a central hub or switch.
Hub – A device used with the Universal Serial Bus or in a star network topology that allows multiple device connections.
Switch – In star networks, a Layer 2 central controlling device. A switch looks at each data frame as it comes through each port.
Ring Topology – Network that is physically wired like a star network but, logically in a ring; passes control from one device to the next in a continuous fashion using a special data packet called a token. Used in Token Ring networks.
Bus Topology – Network wherein all devices connect to a single cable. If the cable fails, the network is down.
Mesh Topology – Network where all devices connect to each other by cabling to provide link redundancy for maximum fault tolerance. Most likely in WANs.

14. Network Topologies
Hub/Switch
Network – Figure # 3

15. Network Topologies
Star Topology
Network – Figure # 4

16. Network Topologies
Logical Ring Topology
Network – Figure # 5

17. Network Topologies
Bus Topology
Network – Figure # 6

18. Network Topologies
Network Topologies
Network – Table # 1

19. Overview of OSI and TCP/IP Layers

20. Basic of TCP/IP
Transmission Control Protocol (TCP) – uses a set of rules to exchange messages with other Internet points at the information packet level
Internet Protocol (IP) – uses a set of rules to send and receive messages at the Internet address level
Is the predominate network protocol in use today (Other includes OSI Model) for interoperable architecture and the internet.
TCP/IP is a result of protocol research and development conducted on experimental packet switched network by ARPANET funded by the defense advanced research projects agency (DARPA). TCP/IP used as internet standards by the internet architecture board (IAB).

21. ISO-OSI Reference Model (1)
Open Systems Interconnection
No one really uses this in the real world.
A reference model so others can develop detailed interfaces.
Value: The reference model defines 7 layers of functions that take place at each end of communication and with each layer adding its own set of special related functions.
Flow of data through each layer at one
It is use to guide product implementors so that their products will consistently work with other products. 21

22. ISO-OSI Reference Model (2)
File Transfer, , Remote Login 
ASCII Text, Sound (syntax layer) 
Establish/manage connection 
End-to-end control & error checking
(ensure complete data transfer): TCP 
Routing and Forwarding Address: IP 
OSI divides telecommunication into seven layers. The layers are in two groups. The upper four layers are used whenever a message passes from or to a user.
The lowest three layers (Up to network layer) are used when any message passes through the host computer.
Message intended for this computer pass to the upper layers.
Message destined for some other host are not passed up to the upper layers but are forwarded to another host.
Physical layer: Bit stream through network at electrical/mechanical level
Two party communication: Ethernet 
How to transmit signal; coding
Hardware means of sending and 
receiving data on a carrier 22

23. Network support Layers
ISO/OSI Reference Model Explained
Application
User support Layers or
Software Layers
Layer - 7
Layer - 6
Layer - 5
Layer - 4
Layer - 3
Layer - 2
Layer - 1
Presentation
Session
Transport
Core layer of the OSI
Network
Network support Layers or
Hardware Layers
Data Link
Physical

24. Data Flow From Application layer
Presentation
Session
Transport
Network
Data Link
Physical
Application
Application Layer is responsible for providing an interface for the users to interact with application services or Networking Services .
Ex: Web browser etc.
Identification of Services is done using Port Numbers (Service Point Addresses).
Port is a logical communication Channel
Port number is a 16 bit identifier.
Total No. Ports – 65535
Server Ports
Client Ports – 65535 24

25. ISO/OSI Layer 7 Service Port No. HTTP 80 FTP 21 SMTP 25 TELNET 23
TFTP 69 25

26. Data Flow From Application Layer21 80 25 67 53 69
Presentation
Session
Transport
Network
Data Link
Physical 26

27. Data flow from Presentation Layer
Application
Presentation
Session
Transport
Network
Data Link
Physical
Presentation Layer It is responsible for defining a standard format to the data.
It deals with data presentation.
The major functions described at this layer are..
Encoding – Decoding
Ex: ASCII, EBCDIC (Text)
JPEG,GIF,TIFF (Graphics)
MIDI,WAV (Voice)
MPEG,DAT,AVI (Video)
Encryption – Decryption
Compression – Decompression
Presentation 27

28. Data Flow from Presentation Layer
Application
Presentation
Session
Transport
Network
Data Link
Physical
Data
Data
Data 28

29. Data Flow from Session layer
Application
Presentation
Session
Transport
Network
Data Link
Physical
Session Layer
It is responsible for establishing, maintaining and terminating the sessions.
Session ID is used to identify a session or interaction.
Examples :
RPC  Remote Procedural Call
Session 29

30. Data Flow from Transport layer
Application
Presentation
Session
Transport
Network
Data Link
Physical
Transport Layer
It provides data delivery mechanism between the applications in the network.
The major functions described at the Transport Layer are..
Identifying Service
Multiplexing & De-multiplexing
Segmentation
Sequencing & Reassembling
Error Correction
Flow Control
Transport
Transport Layer provides data delivery mechanism between the applications in the network 30 30

31. Services are identified at this layer with
Identifying a Service
Services are identified at this layer with
the help of Port No’s.
The major protocols which takes care of Data Transportation at Transport layer are…TCP,UDP
Transmission Control Protocol
Connection Oriented
Supports Ack’s
Reliable communication
Slower data Transportation
Protocol No is 6
Eg: HTTP, FTP, SMTP
User Datagram
Protocol
Connection Less
No support for Ack’s
Unreliable communication
Faster data Transportation
Protocol No is 17
Eg: DNS, DHCP, TFTP
TCP
UDP 31

32. Data flow from Transport Layer
Application
Presentation
Session
Transport
Network
Data Link
Physical
Data
Data
Data TH
Segment
Data 32

33. Network Layer Network Layer
It provides Logical addressing & Path determination (Routing) in this layer.
The protocols that work in this layer are:
Routed Protocols:
IP, IPX, AppleTalk.. Etc
Routed protocols used to carry user data between hosts.
Routing Protocols:
RIP, OSPF.. Etc
Routing protocols performs Path determination (Routing).
Application
Presentation
Session
Transport
Network
Data Link
Physical
Network 33

34. Devices that work at Network Layer are Router, Multilayer switch etc..
Data flow from Network Layer
Application
Presentation
Session
Transport
Network
Data Link
Physical
Data
Data
Data
Devices that work at Network Layer
are Router, Multilayer switch etc..
Segment NH
Packet
Segment 34

35. Data link Layer Datalink Layer It has 2 sub layers
MAC (Media Access Control) It provides reliable transit of data across a physical link.
It also provides ERROR DETECTION using CRC (Cyclic Redundancy Check) and ordered delivery of Frames.
Ex: Ethernet, Token ring…etc
LLC (Logical Link Control)
It provides communication with Network layer.
Negotiates with Network Layer using SAP & SNAP protocols
Application
Presentation
Session
Transport
Network
Data Link
Physical
Data Link 35

36. Devices that work at Data link layer are Switch, Bridge etc..
Data flow from Data Link Layer
Application
Presentation
Session
Transport
Network
Data Link
Physical
Data
Data
Data
Segment
Devices that work at Data link layer are Switch, Bridge etc..
Packet DH DT
Frame
Packet
Packet 36

37. Physical Layer Physical Layer It defines the electrical, Mechanical &
functional specifications for communication between the Network devices.
The functions described at this layer are..
Encoding/decoding:
It is the process of converting the binary data
into signals based on the type of the media.
Copper media : Electrical signals of different voltages
Fiber media : Light pulses of different wavelengths
Wireless media: Radio frequency waves
Mode of transmision of signals:
Signal Communication happens in three different modes
Simplex, Half-duplex, Full-duplex
Protocols works at physical layer: 10BaseT, 100BaseT,
V.35, RS-232..etc
Application
Presentation
Session
Transport
Network
Data Link
Physical
Physical 37

38. Data flow from Physical Layer
Application
Presentation
Session
Transport
Network
Data Link
Physical
Data
Data
Data
Segment
Packet
Devices that work at
physical layer are ..
Hub, Repeater.. Etc
Frame
Bits 38

39. Data Encapsulation & De-capsulationB
Application
Presentation
Session
Transport
Network
Data Link
Physical
Data
Data
Data
Data
Data
Data TH
Segment
Data TH
Data
Segment TH NH
Packet
Segment NH
Segment
Packet NH DT DH
Frame
Packet
Packet
Packet DT
Packet DH
Frame DT DH
Bits
Bits 39

40. OSI Vs TCP/IP & De-capsulation
OSI Layers
TCP/IP Layers
Application
Presentation
Session
Transport
Network
Data Link
Physical
Application
Host-to-Host
Internet
Network
Access 40

41. Associated TCP/IP Protocols & Services
HTTP
This protocol, the core of the World Wide Web, facilitates retrieval and transfer of hypertext (mixed media) documents. Stands for the HyperText Transfer protocol
Telnet
A remote terminal emulation protocol that enables clients to log on to remote hosts on the network.
SNMP
Used to remotely manage network devices. Stands for the Simple Network Management Protocol.
DNS
Provides meaningful names like achilles.mycorp.com for computers to replace numerical addresses like Stands for the Domain Name System.
SLIP/ PPP
SLIP (Serial Line Internet Protocol) and PPP (Point to Point Protocol) encapsulate the IP packets so that they can be sent over a dial up phone connection to an access provider’s modem.

42. Overview of Networking Devices

43. Hubs
Intelligent hubs have console ports, to allow monitoring of the hubs status and port activity.
Passive hubs just repeat any incoming signals to every port available, therefore does not act as a line repeater.
Passive hubs just split signals to multiple ports but do not regenerate the signals, which means that they do not extend a cable’s length. They only allow two or more hosts to connect to the same cable segment.
Active hubs regenerate signals.
Hubs utilise star topology.

44. Advantages Disadvantages Hub Pros & Cons
As an active hubs regenerate signals, it increases the distance that can be spanned
by the LAN (up to 100 meters per segment).
Hubs can also be connected locally to a maximum of two other hubs, thereby
increasing the number of devices that can be attached to the LAN.
Active hubs are usually used against attenuation, which is a decrease in the strength
of the signal over distance.
Disadvantages
Bandwidth is shared by all hosts i.e. 10Mbs shared by 25 ports/users.
Can create bottlenecks when used with switches.
Have no layer 3 switching capability.
Most Hubs are unable to utilise VLANS.

45. Switches A switch is a multi-port bridge.
It operates at OSI data link layer 2.
It stores MAC addresses in an internal lookup table.
Temporary switched paths are created between the frame’s source destination.
Some Switches have limited layer 3 IP routing capabilities.
Switches can be configured to use VLANS.
Switches support spanning tree protocol to create resilient networks.

46. Example Topology
Switch
Hub
UTP
10Mbs
Fibre
100Mbs 46

47. Transceiver Modules
Connects to any Auxiliary Unit Interface port (AUI).
Operates at OSI layer 1.
Allows multiple media types to connect to an Ethernet device. i.e. fibre ST/SC,Co-ax cable, and UTP.
UTP
Co-axial

48. Routers Routers are OSI network layer 3 devices
Using interface modules can connect different layer 2 technologies e.g. Ethernet, FDDI, token ring etc…
Routers have the capability to interconnect network segments or entire networks (WANS/MANS).
These devices examine incoming packets to determine the destination address of the data. It then examines its internal routing table to choose the best path for the packet through the network, and switches them to the proper outgoing port.

49. Example Router Topology

50. Summary and References
Please go through below link for further Study:

51. Thank You