Showing posts with label Computer Network. Show all posts
Showing posts with label Computer Network. Show all posts

Different Network Connectivity Devices


1. Network Hub

A device that lets multiple computers talk to each other over a network is called a network hub. The computers connect to the network hub via ethernet ports. Hubs typically have four to twelve ethernet ports. Small local area networks (LANs) are ideal applications for these devices.

There are many ports in a hub. One of these ports is used to connect a computer that wants to connect to the network. A data frame is broadcast to every other port when it arrives at a port, regardless of whether it is intended for a specific device.


2. Network Switch

A network switch forwards data packets to and from devices within a network, typically a local area network (LAN*). A switch, in contrast to a router, only sends data to the device it is intended for (either another switch, a router, or the computer of a user), not to multiple device networks.

Data packets are routed between devices by a network switch. Instead of sending packets to networks like a router does, switches send them directly to devices.

Different Kinds of Switch

  • Unmanaged SwitchSwitches that are not managed are made to simply plug in and run, with no settings to set. These are acceptable for use in minimal networks with minimal requirements.
  • Managed SwitchManaged switches are customizable, fully configurable, and offer a variety of performance data. Because of these characteristics, they are better suited for supporting critical activities and larger networks.
  • POE Switch - Power over Ethernet (PoE) is a type of technology that connects wireless access points, IP cameras, and VoIP phones by transmitting electric power and data over twisted-pair Ethernet cables. Instead of using separate cables for each connected edge device, it makes it possible to connect them all with a single RJ45 patch cable.


3. Wireless Access Point

An access point is a piece of networking hardware that transmits and receives radio signals and connects wirelessly enabled devices to a network. A CPU, radio transceivers, antennas, and software make up access point hardware. A wireless local-area network, or WLAN for short, is made up of all of these parts. Users can connect their devices to a network without using cables or wires with the WLAN.

Different Kinds of Wireless Access Point
  • Wireless Repeater - A type of device known as a WiFi repeater (Wireless Repeater) uses a signal from a wireless router or wireless access point and distributes it to create a second network. A WiFi repeater can be utilized in your home or business network to establish a connection between two or more hosts using the IEEE 802.11 protocol when the distance between them is insurmountable.
  • Wireless Mesh - Wireless access point (WAP) nodes installed at each network user's location are connected to form a mesh network known as a wireless mesh network (WMN). Because each node only needs to transmit as far as the next node, the networking infrastructure is decentralized and simplified. It is possible that WMNs are not connected to the internet.
  • Generations of Wifi - Standards for Wi-Fi have been constantly evolving ever since it was first made available to consumers in 1997, typically leading to faster speeds and expanded coverage. A new name is given to each new capability to set the standards apart. When new features are included in the original IEEE 802.11 standard, they become known as amendments.

4. Router

The purpose of a router, which can be a physical or a virtual internetworking device, is to receive, evaluate, and transmit data packets between computer networks. A data packet's destination IP address is looked at by a router, which then looks at the packet's headers and forwarding tables to figure out the best way to move the packets. A router is merely a device that facilitates communication between the internet and connected home devices. It "routes" traffic between devices and the internet, as its name implies. The internet network in your home relies heavily on a router. It makes it possible to connect your laptop, smartphone, smart TV, and other devices to the Wi-Fi in your home.


5. Network Bridge

A device that divides a network into segments is called a network bridge. As a result, there are fewer collisions on the network because each segment represents a distinct collision domain. Since each collision domain has its own bandwidth, a bridge also speeds up the network. The OSI model's Data link layer (Layer 2) is where a bridge operates. It decides whether to forward or filter incoming traffic after examining it. The destination MAC address is checked for in each Ethernet frame that comes in. The frame is forwarded to the other network segment if the bridge determines that the destination host is on that segment.


6. Network Firewall 

A firewall is a network security solution that stops unwanted traffic from entering your network. Based on a set of pre-programmed rules, firewalls prevent malware from entering. Users within the network may also be prevented from accessing certain websites and applications by these rules.

The straightforward concept that network traffic from less secure environments should be authenticated and inspected prior to moving to a more secure environment is the foundation of firewalls. Unauthorized applications, devices, and users are prevented from entering a protected network environment or segment as a result. Your network's computers and devices are vulnerable to hackers without firewalls, making you an easy target for attacks.

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Computer Network - UTP AND STP CABLE applications

Different types of UTP and STP cable.

UTP Cable - Unshielded twisted pair (UTP) cables are frequently utilized in the computer and telecommunications industries as telephone wires and Ethernet cables. The conductors that make up a single circuit in a UTP cable are twisted around one another to cancel out external sources of electromagnetic interference (EMI).




STP Cable - Shielded Twisted Pair (STP) has four wire pairs with each wire twisted together. However, STP differs in that it has copper braided around the wires and is surrounded by a foil shield, providing greater protection against external electromagnetic interference. The shielding makes the cable physically larger, install and terminate it more difficult, and cost more than UTP. STP utilizes RJ-45, RJ-11, RS-232, and RS-449 connectors for applications in electrically noisy environments. STP also comes in Cat 2, 3, 4, or 5 grades, like UTP; However, for all data applications, only Cat5 is recommended. With no signal regenerating device, the maximum cable length and data transfer rate are 100 meters and 500 Mbps, respectively.



Straight Through and Crossover cable applications.

Straight through cables are twisted pair cables that connect computers to a network hub and local area networks, like routers. For both of the cable's ends, use the same wire standard: T568A and T568B should be used for the ends. One end of straight-through cables can only communicate at a time. Cables come in two primary varieties. They are the best for connecting two different kinds of networking equipment. For instance, they can be utilized to connect a computer to a switch, router, or printer.


Two or more computers can be connected with a crossover cable. The transmission and receive signals are flipped by the crossover cables' internal wiring. It connects two devices of the same type, which is common: for instance, connecting two switches or computers. Crossover Ethernet cables are very similar to standard Ethernet cables in terms of appearance. Nevertheless, they differ in the order in which the wires are arranged. This kind of Ethernet cable is designed to connect directly to similar network devices via Ethernet. Most of the time, crossover cables connect two hosts directly.You should use straight-through cable when you want to connect two devices of different types, then use a crossover cable when you want to connect two devices of the same type. 


When connecting two devices of different types, you should use a straight-through cable; when connecting devices of the same type, you should use a crossover cable. 



T-568A and T-568B standards

There are two major Unshielded Twisted Pair Cable wiring standards used widely in networking industry. Telecommunications Industry Association (TIA)/Electronic Industries Alliance (EIA) developed the TIA/EIA 568A & TIA/EIA 568B standards for Unshielded Twisted Pair wiring. TIA/EIA 568A and TIA/EIA-568B standards determine the order of the wires placed in the RJ45 connector. Functionally, there is no difference between TIA/EIA 568A and TIA/EIA-568B standards. Only the difference is that the position of Green and Orange wires are switched. 





What is a Patch Panel and what its purpose in in Computer Network?

A patch panel is an efficient and adaptable networking device that makes it much simpler to move, add, or modify the cabling infrastructure in the future and keeps your data center or server room organized. Based on the cables they are working with, patch panels in typical data center infrastructure typically fall into two categories: Ethernet patch panels in addition to fiber optic patch panels. Both of them can be customized to meet a variety of network cabling requirements and come in a variety of designs, configurations, and port counts. Since patch panels are used for cabling installations in almost all business network setups, they are one of the few components that is used in both copper and fiber cabling networks. Patch panels give you flexibility and eliminate the need to re-run cables or move equipment if something breaks or needs to be changed. Punching down the cable to patch panels, for instance, can provide mechanical relief to the relatively costly switch ports. If the cable from the ceiling or wall were to be plugged directly into a switch port, it could be pulled, pushed, and so on. And it doesn't take much for an RJ-45 plug to lose connectivity in this way, either with the inside of a switch port or with the cable itself.

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