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RING TOPOLOGY

Also known as a ring network, the ring topology is a type of computer network configuration where each network computer and device are connected to each other forming a large circle (or similar shape). Each packet is sent around the ring until it reaches its final destination. Today, the ring topology is seldom used.


Because a ring topology provides only one pathway between any two nodes, ring networks may be disrupted by the failure of a single link. A node failure or cable break might isolate every node attached to the ring.


AdvantagesVery orderly network where every device has access to the token and the opportunity to transmitPerforms better than a star topology under heavy network loadCan create much larger network using Token RingDoes not require network server to manage the connectivity between the computersDisadvantagesOne malfunctioning workstation  can create problems for the entire networkMoves, adds and changes of devices can affect the networkNetwork adapter ca…

BUS TOPOLOGY

In local area networks where bus topology is used, each machine is connected to a single cable. Each computer or server is connected to the single bus cable through some kind of connector. A terminator is required at each end of the bus cable to prevent the signal from bouncing back and forth on the bus cable. A signal from the source travels in both directions to all machines connected on the bus cable until it finds the MAC address or IP address on the network that is the intended recipient. If the machine address does not match the intended address for the data, the machine ignores the data. Alternatively, if the data does match the machine address, the data is accepted. Since the bus topology consists of only one wire, it is rather inexpensive to implement when compared to other topologies. However, the low cost of implementing the technology is offset by the high cost of managing the network. Additionally, since only one cable is utilized, it can be the single point…

NETWORK TOPOLOGY

In computer networking, topology refers to the layout of connected devices.
Network topology is defined as the interconnection of the various elements (links, nodes, etc.) of a computer network. Network Topologies can be physical or logical. Physical Topology means the physical design of a network including the devices, location and cable installation.







TYPES OF OFC

On the basis of fibre(core) OFC is of two types

Single Mode Multi ModeSINGLE MODE

Single-mode fiber is a type of fiber optic cable through which only one light signal can travel at a time.


MULTI MODE


Multi-mode fiber is a type of fiber optic cable which is thick enough for light to follow several paths through the code.

CO-AX Vs OFC

BRIEF OVER VIEW OF FIBER OPTIC CABLE ADVANTAGES OVER COPPER:• SPEED: Fiber optic networks operate at high speeds - up into the gigabits
BANDWIDTH: large carrying capacity
DISTANCE: Signals can be transmitted further without needing to be "refreshed" or strengthened.
RESISTANCE: Greater resistance to electromagnetic noise such as radios, motors or other nearby cables.
MAINTENANCE: Fiber optic cables costs much less to maintain.

OPTICAL FIBRE CABLE

An optical fiber cable is a cable containing one or more optical fibers. The optical fiber elements are typically individually coated with plastic layers and contained in a protective tube suitable for the environment where the cable will be deployed.

DESIGN

OFC  made up of 3 layers.
fibre or corecladdingouter jacket
In practical fibers, the cladding is usually coated with a tough resin buffer layer, which may be further surrounded by a jacket layer, usually plastic. These layers add strength to the fiber but do not contribute to its optical wave guide properties. Rigid fiber assemblies sometimes put light-absorbing ("dark") glass between the fibers, to prevent light that leaks out of one fiber from entering another. This reduces cross-talk between the fibers, or reduces flare in fiber bundle imaging applications.                                                                                                                                              

The advantages of using …

UNSHIELDED TWISTED PAIR CABLE

UTP (Unshielded Twisted Pair)

UTP, or Unshielded Twisted Pair, is a type of cable used in telecommunications and computer networks. It consists of different numbers of copper wire that have been twisted into matching pair. It differs from screened and shielded twisted pair, in that the individual pair are not protected with additional protection from interference. Each copper wire is insulated, and the groups of twisted pair have a sheathing holding them together, but no additional insulation is provided. UTP comes in many different types and sizes, and is primarily used as node cabling, meaning it runs from a backbone unit to the individual components on the network.

Types


UTP comes in different types called Categories, often abbreviated as "Cat". The most common are Cat 3, Cat 5e, and Cat 6. The higher the category number, the more twists per foot in the pair, and the better protection from interference. Cat 3 is usually used for home telephone systems. Cat 5e is the industr…

TWISTED PAIR CABLE

A type of cable that consists of two independently insulated wires twisted around one another. The use of two wires twisted together helps to reduce crosstalk and electromagnetic induction. While twisted-pair cable is used by older telephone networks and is the least expensive type of local-area network (LAN) cable, most networks contain some twisted-pair cabling at some point along the network.

OR

Twisted pair cable consists of a pair of insulated wires twisted together. It is a cable type used in telecommunication for very long time. Cable twisting helps to reduce noise pickup from outside sources and crosstalk on multi-pair cables.

TYPES
STPUTPSTP (shielded twisted pair)


Short for Shielded Twisted-Pair cable, STP is a type of cable originally developed by IBM for Token Ring that consists of two individual wires wrapped in a foil shielding to help provide a more reliable data communication. Shielded twisted pair is a special kind of copper telephone wiring used in some business install…

COAXIAL CABLE

Coaxial cable, or coax, is an electrical cable with an inner conductor surrounded by a flexible, tubular insulating layer, surrounded by a tubular conducting shield. The term coaxial comes from the inner conductor and the outer shield sharing the same geometric axis.

Coaxial cable design choices affect physical size, frequency performance, attenuation, power handling capabilities, flexibility, strength and cost. The inner conductor might be solid or stranded; stranded is more flexible. To get better high-frequency performance, the inner conductor may be silver plated. Sometimes copper-plated iron wire is used as an inner conductor.

Coaxial cable is still the most common means of data transmission over short distances. This established technology provides a wide range of products suitable for most electronic systems. As computer speed increases and services require more data bits per second, the upper limits of coaxial cable's carrying capacity are being reached. Fiber-optic cable…

TRANSMISSION MEDIA

A transmission medium (plural transmission media) is a material substance (solid, liquid, gas, or plasma) which can propagate energy waves. For example, the transmission medium for sound received by the ears is usually air, but solids and liquids may also act as transmission media for sound.


The term transmission medium can also refer to the technical device which employs the material substance to transmit or guide the waves. Thus an optical fiber or a copper cable can be referred to as a transmission medium.

A transmission medium can be classified as a:
Bounded/Guided   Waves are guided along a solid medium such as a transmission line.
CO-AX(Coaxial cable)Twisted PairOptical fibre cableUnbounded/Unguided  Transmission and reception are achieved by means of an antenna.
MicrowaveradiowaveInfra red RayXrayGamma ray etc.

NETWORK ELEMENTS

There are basic three network elements to develop a Computer Network.
NETWORK SERVICESCOMMUNICATION PATHCOMMUNICATION PROTOCOLNETWORK SERVICES

Network services are the foundation of a networked computing environment. Generally network services are installed on one or more servers to provide shared resources to client computers

Common network services include:


Application
Authentication servers
Directory services
Dynamic Host Configuration Protocol (DHCP)
DNS
e-Mail/Message
Print
File service
etc.

TYPES OF NETWORK

One way to categorize the different types of computer network designs is by their scope or scale. For historical reasons, the networking industry refers to nearly every type of design as some kind of area network. Common examples of area network types are:



LAN - Local Area Network


WLAN - Wireless Local Area Network


WAN - Wide Area Network


MAN - Metropolitan Area Network


SAN - Storage Area Network, System Area Network, Server Area Network, or sometimes Small Area Network


CAN - Campus Area Network, Controller Area Network, or sometimes Cluster Area Network


PAN - Personal Area Network


DAN - Desk Area Network


LAN and WAN were the original categories of area networks, while the others have gradually emerged over many years of technology evolution.

Personal Area Network (PAN)

The smallest type of network, a PAN simply involves connecting one person's computer to a number of devices or peripherals. Usually, all devices, such as printers, PDAs, and telephones, are within a few feet of the…

COMPUTER NETWORKS

Network means Interconnection. A computer Network is interconnection between two or more autonomous computers or computer like devices.
                   OR 
computer network, often simply referred to as a network, is a collection of computers and devices connected by communications channels that facilitates sharing of resources like information, hardware,files, etc.


PURPOSE



Computer networks can be used for several purposes:
Facilitating communications. Using a network, people can communicate efficiently and easily via e-mail, instant messaging, chat rooms, telephone, video telephone calls, and video conferencing.Sharing hardware. In a networked environment, each computer on a network can access and use hardware on the network. Suppose several personal computers on a network each require the use of a laser printer. If the personal computers and a laser printer are connected to a network, each user can then access the laser printer on the network, as they need it.Sharing files, data, an…

WELCOME AGAIN in NEW AAVTAR

Hi Friends
               This is the  time I start blogging again. You can say the NEW AAVTAR. As previous the blogging based on Computer Science, Information Technology, related topics and many more. Beside blogging i also provide you some important and useful widgets. I think you can benefited from these. This time i also think to complete the work which is pending from last one and half years. Yes you think right the committed website for you. Next in next Post. ENJOY...