Chapter-1
Basics of Networking
- what is networking ?
- what are the terms used in networking?
- How to learning networking ?
- Is Networking is tedious to learn ?
- what are the networking devices ?
- what is LAN?
- What is Wan ?
now the big question arise in mind , how could we visualize if we don't know the terms used in networking , so you just don't worry our first step is to stat with basic term and terminology used in networking.
Summary & Basic concepts
In this section we will cover almost the topic in a very brief manner but will cover detail in later post,
the whole Networking concept basically revolves around two concepts
- LAN: Local area Network
- WAN: wide area network
Note:- To understand the complete fundamental not only for networking but any thing you want to learn please follow some question i.e what, which, when, where, how,
LAN – A local area network or LAN is a network that has the following characteristics.
- · It usually exists within a home, building or group of buildings.
- · It is usually administered and managed by a single entity, business, or organization.
- · In addition, a LAN typically consists of some form of an Ethernet network, i.e
o Fast Ethernet (100Mb),
o Gigabit Ethernet (1000Mb),
it could be implemented in
o Twisted pair copper cables,
o Multi-mode fiber optic cables, or
o Some form of wireless technology.
LAN is the way how devices connected locally at a single physical location (L2 switch /computer or end users)
WAN – wide area networks are the networks that interconnect all of the local area networks, ie. it is the network of LANs. WANs are typically managed and controlled by internet service providers (ISPs). For managing a WAN Router, Switch, Modem, media converter are needed Instead of using Ethernet, WANs typically implement different technologies like DSL, PPP, Frame Relay, ATM, etc.
"it is the way how devices at different location connected together" ( Router /L3 Devices/Media converter)
Lan and Wan basically define a way by which devices are interconnected with each other, and how data route from source to destination but the level of exchange of information could be understand by discussing, Internet, Intranet, Extranet – What is it? and what is the difference between the internet, intranet, and extranet?
Internet – inter means between, and net is short for networks, so internet literally means between networks. So what is the internet? The network of networks. The network formed by connecting all of the networks together i.e The "Internet" is a global wide area network that connects computer systems across the world.
Intranet – intra means within and net means network, so intranet means within the network. i.e all system connected together could communicate but they could not go to the internet to anything, i.e if you are accessing the server of school which is not connected to the internet, then all system connected with the server can communicate with that server utility but could not browse any web page, bank network is the live example of it, they are internally connected but could not browse web page.
Extranet – extra means in addition to, and net means network, so extranet literally means in addition to the network. An extranet is an area of the network that users who are outside of the network can remotely connect into. This can be done with VPN services, allowing users with permission to VPN into an area of the network.
Ethernet:-is a family of computer networking technologies commonly used in local area networks, metropolitan area networks and wide area networks. It was commercially introduced in 1980 and first standardized in 1983 as IEEE 802.3.
Ethernet basically describe the:-
- Topology types i.e (Bus, star , Ring , Mesh, Hybrid etc )
- Media Access concept i.e ( CSMA/CD, CSMA/CA)
- Transmission Media i.e (Fiber optics, STP/UTP,: Cat3, Cat4, Cat5, Cat5e, Cat6 etc)
- Frame Type i.e (Ethernet 802.2, 802.3 etc
- Physical Address i.e (Mac Address) of device
Networking Devices
Firewall- firewall is a network security system that monitors and controls incoming and outgoing network traffic based on predetermined security rules. A firewall typically establishes a barrier between a trusted internal network and un-trusted external network, such as the Internet.
Server- A server is a machine or computer program that provides data or functionality for other machines or programs. Servers are the lifeblood of any network. They provide the shared resources that the network users need, such as e-mail, Web services, databases, file storage, etc
Router- it is a device which used to connect LAN & WAN, which generally provide the connectivity between two or more location, and do a major job of routing and allow communication b/w one network with another network.
Repeater – A repeater operates at the physical layer. Its job is to regenerate the signal over the same network before the signal becomes too weak or corrupted so as to extend the length to which the signal can be transmitted over the same network. An important point to be noted about repeaters is that
- They do not amplify the signal.
- When the signal becomes weak, they copy the signal "bit-by-bit" and regenerate it at the original strength.
- It is a 2 port device
Types
- Active Hub:- These are the hubs which have their own power supply and can clean, boost and relay the signal along with the network. It serves both as a repeater as well as wiring center. These are used to extend the maximum distance between nodes.
- Passive Hub :- These are the hubs which collect wiring from nodes and power supply from active hub. These hubs relay signals onto the network without cleaning and boosting them and can’t be used to extend the distance between nodes.
Bridges:- these are the networking devices which are used for reducing the collision domain by dividing the one network into two networks, bridge takes the routing decisions based on the MAC table. A network bridge is a computer networking device that creates a single aggregate network from multiple communication networks or network segments. This function is called network bridging.
It has a single input and single output port, i.e 2 port device.
Switch:- A network switch is a multiport network bridge that uses MAC addresses to forward data at the data link layer. Some switches can also forward data at the network layer i.e Layer-3 by additionally incorporating routing functionality. basically switches are of two type
- Layer 2 switches..........don't takes the routing decisions
- Layer 3 switches...........Takes the routing decisions also
Modem:- Modulator/Demodulator is hardware device that converts data into a format suitable for a transmission medium so that it can be transmitted from computer to computer (historically over telephone wires). A modem modulates one or more carrier wave signals to encode digital information for transmission and demodulates signals to decode the transmitted information. The goal is to produce a signal that can be transmitted easily and decoded reliably to reproduce the original digital data.
Media Converter:- An Ethernet media converter is a device designed to interconnect different networking media such as fiber and coaxial cables to facilitate communication between them. It often comes in the form of a small box where the two different networking cables can be plugged in.
Network :- Cable,Connectors Types & Specifications
Network cable & connector such as STP/UDP, Rj-45, Rj-11, USB, MT-RJ, Coaxial BNC, LC Local Connector, MT-RJ, USB BNC and AUI is used to connect .
Networking cables:- are networking hardware used to connect one network device to other network devices or to connect two or more computers to share printers, scanners, services etc. Different types of network cables, such as coaxial cable, optical fiber cable, and twisted pair cables, are used depending on the network's Requirement:- topology, and size. The devices can be separated by a few meters (e.g. via Ethernet) or nearly unlimited distances (e.g. via the interconnections of the Internet).
STP/UTP:- The basic difference between UTP and STP is
- · UTP - unShielded twisted pair is a cable with wires that are twisted together to reduce noise and cross talk.
- · STP-Shielded twisted pair is a twisted pair cable confined in foil or mesh shield that guards the cable against electromagnetic interference.
RJ:- A registered jack (RJ) is a standardized telecommunication network interface for connecting voice and data equipment to a service provided by a local exchange carrier or long distance carrier.
RJ-11 (Registered Jack)
Standard telephone cable connectors, RJ-11 has 4 wires (and RJ-12 has 6 wires). RJ-11 is the acronym for Registered Jack-11, a four- or six-wire connector primarily used to connect telephone equipment.
RJ-11 Pin
|
Signal Name
|
1
|
VCC (5 volts regulated)
|
2
|
Power Ground
|
3
|
One Wire Data
|
4
|
One Wire Ground
|
RJ-45 (Registered Jack)
The acronym for Registered Jack-45 is RJ-45. The RJ-45 connector is an eight-wire connector that is commonly used to connect computers to a local area network (LAN), particularly Ethernet LANs. Although they are slightly larger than the more commonly used RJ-11 connectors, RJ-45s can be used to connect some types of telephone equipment.
USB (Universal Serial Bus)
Universal Serial Bus, or USB, is a computer standard designed to eliminate the guesswork in connecting peripherals to a PC. It is expected to replace serial and parallel ports. A single USB port can be used to connect up to 127 peripheral devices, such as mice, modems, keyboards, digital camera's, printers, scanners, MP3 players and many more. USB also supports Plug-and-Play installation and hot plugging.
- USB 1.1 standard supports data transfer rates of 12 Mbps.
- USB 2.0 specification defines a new High-speed transfer rate of 480 Mb/sec.
- USB 3.0 Speed upto 5 gbps
- USB 3.1 Gen-1 super speed upto 10 gbps
- USB 3.1 Gen-2 super speed+ upto 20 gbps
USB 2.0 is fully compatible with USB 1.1 and uses the same cables and connectors. USB has with two connector types. The first is Type A (on the right), This connector connects to the PC's USB port. The Type B (on the left) connector and is for connecting to the relevant peripheral. Where as the type A connector is truly standard, the Type B connector could be changed in size etc. with individual peripherals meaning they require there own unique
F-Type
The F connector is a type of RF connector commonly used for cable and universally for satellite television. They are also used for the cable TV connection in DOCSIS cable modems, usually with RG-6 tri-shield cable. The F connector is inexpensive, yet has good performance up to 1 GHz. One reason for its low cost is that it uses the center wire of the coaxial cable as the pin of the male connector. The male connector body is typically crimped onto the exposed outer braid. Female connectors have a 3/8-32 thread. Most male connectors have a matching threaded connecting ring, though push-on versions are also available.
ST (Straight Tip) and SC (Subscriber Connector or Standard Connector)
Fiber network segments always require two fiber cables: one for transmitting data, and one for receiving. Each end of a fiber cable is fitted with a plug that can be inserted into a network adapter, hub, or switch. In the North America, most cables use a square SC connector (Subscriber Connector or Standard Connector) that slides and locks into place when inserted into a node or connected to another fiber cable, Europeans use a round ST connector (Straight Tip) instead.
SC connector ST connector
Fiber LC (Local Connector)
These connectors are used for single-mode and multimode fiber-optic cables. FC connectors offer extremely precise positioning of the fiber-optic cable with respect to the transmitter's optical source emitter and the receiver's optical detector. FC connectors feature a position locatable notch and a threaded receptacle.
MT-RJ (Mechanical Transfer Registered Jack)
MT-RJ connectors are used with single-mode and multimode fiber-optic cables. The MT-RJ connectors are constructed with a plastic housing and provide for accurate alignment via their metal guide pins and plastic ferrules.
Used for Gigabit ethernet. To connect to modules with MT-RJinterfaces, use multimode fiber-optic cables.
EIA/TIA:- Electronic Industries Alliance/Telecom Industries Association. Basically provide the color combination mechanism for STP/UDP cable in order to provide better/ faster communication.
 |
| Note:- In Normal case only pin 1,2,3,& 6 used for data transfer, but for better speed management, 4,5,7 & 8 are also used |
- Cross over cable :- for different layer devices i.e Router to switch
- Straight through cable :- for same level devices i.e switch to switch
- Roll over cable:- console cable (for 1st use of device)
 |
| Pin layout of Crossover cable and Straight through Cable |
What Is Crossover Cable?
A crossover cable is a type of Ethernet cable used to connect computing devices together. the RJ45 crossover cable uses two different wiring standards: one end uses the T568A wiring standard, and the other end uses the T568B. The internal wiring of Ethernet crossover cables reverses the transmit and receive signals. It is most often used to connect two devices of the same type: e.g. two computers or two routers or two switches to each other.
Straight Through n Crossover Cable
Usually, straight through cables are used for connecting unlike devices. And crossover cables are use for connecting alike devices.
straight through cable used for the following cabling:
Switch to router
Switch to PC or server
Hub to PC or server
Use crossover cables for the following cabling:
Hub to hub
Router to router
Switch to switch
Switch to hub
PC to PC
Router Ethernet port to PC NIC
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Aise hi share krte rhiye sir
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