Types of Network Cable

There are three basic types of networking cables:

1: Twisted Pair

2: Coaxial cable

3: Fiber Optics

BASIC CONCEPT TO UNDERSTAND ABOUT ALL CABLE TYPES

ATTENUATION (Distance Limit):

                                In nearby all cable there is a distance limit at which the signal on the wire wakness and no longer can be recognized.

ELECTROMAGNTIC INTERFACE

                                                                Virtually all electrical devices emit electromagnetic waves that can cause interference and impair the signal of other devices.

RADIO FREQUENCY INTERFERENCE (RFI):

                                                                                   Devices that broadcast wireless or radio signals can produce interference through radio waves transmissions picked up by other electrical devices, which is the case of EMI.

CANCELLATION:

                                The electromagnetic fields of two wires placed in close proximity can cancle out each other. This is generally a good thing and helps control the signal being sent over the individual wires, but too much cancellation can destroy the integrity of the signal carried on either wire.

PDU ( Protocol Data Unit) Names of the Layers of the OSI Model

What OSI Model does?

OSI Model Describes how information moves from an application program running on on networked computers to an application program running on another networked computer. OSI prescribes the steps in the process of transferring data, in the form of ones and zeroes, over a transmission medium to another computer or device on a network.

Layer Model In ISO OSI Reference Model

ISO OSI REFERENCE MODEL

• Industry standards Organization, Open System Interconnection Reference Model.
• All cisco networking is the OSI Reference Model
• OSI Model is the foundation of all network communications Cisco and othrs.
• OSI Reference Model has seven layers.
• Department of Defense has five layers.
• A layered model is one that takes a task, such as data communications, and breaks it down into a series of tasks, activities, or components.   

Fiber Distributed Data Interchange (FDDI)- The Double Ring Network

FDDI is an ANSI (American national Standards Institute) standard that defines a dual ring technology that operates at 100 mbps over fiber optics cabling.
FDDI is better suited for networks that operate over large geographic area or in electronically environments, or for networks that have large bandwidth demands.

What is Token Ring Network & How It Works?

Token Ring Network:
                                    Its usually operate at either 4 Mbps or 16 Mbps. token Ring network are laid out in loop that starts and ends at the same node forming a ring.
Working:
                A Token Ring node receives message only from its nearest upstream neighbor (NAUN) and sends signals to its downstream neighbor. Token Ring use a token passing access method, in which only the workstation or computer holding the token is allowed to transmit on the network. As the workstation or computer completes its task, it places the token on the network for another node to use.

What is Ethernet & How Its Work?

Ethernet:
                By definition built on a bus topology that operates on baseband rates 10 Mbps or 1,000 Mbps.
How Ethernet Works:
                                    Ethernet network employ an access method CSMA/CD (Carrier Sense Multiple Access/Collision Detection). Under CSMA/CD, when a station wants to send information over the network, it listens for other stations broadcasting. If the network is not in use, it sends the message. On Occasion, two stations may broadcast at the same time and a collision occurs, when this happens each station retransmits its message using a back-off algorithm that specifies a random period of time each workstation or computer should wait before re-transmitting.

Starting CCNA from Topologies

Topology is the physical layout of the computer, other nodes and cabling of the network.
Some General Topologies:
1: BUS TOPOLOGY:
                                    Nodes/computers are connected to a central cable, called a backbone, which runs the length of the network.
2: RING TOPOLOGY:
                                      The primary network cable is installed as a loop, or ring, and the workstations/computers are attached to the primary cable at points of the ring.
3: STAR TOPOLOGY:
                                       Each workstation/computer connects directly to the central server with its own cable.

A Little Bit About CCNA

Cisco Systems, Inc. sponsors a complete hierarchy of career certifications that center on its routing. Cisco Systems is the leading internetworking company in the world, its only natural that certification on its equipment and software is a valuable credential for a networking professional.

Important Notice

All topics and theory which you will read or see in this blog is collected from many resources. All is not my own and I specially thanks to all of them and all the resources. This is only for educational purpose and to help the students and other computer users.