What is a Wi-Fi network?

A WiFi network is simply an internet connection that’s shared with multiple devices in a home or business via a wireless router. The router is connected directly to your internet modem and acts as a hub to broadcast the internet signal to all your Wi-Fi enabled devices. This gives you flexibility to stay connected to the internet as long as you’re within your network coverage area.

HOW DOES WI-FI WORK?

Wi-Fi networks have no physical wired connection between sender and receiver. Instead, they function by using radio frequency (RF) technology a frequency within the electromagnetic spectrum associated with radio wave propagation. When an RF current is supplied to an antenna, an electromagnetic field is created that then is able to propagate through space.

The cornerstone of any wireless network is an access point (AP). The primary job of an access point is to broadcast a wireless signal that computers can detect and use to establish a connection to the network. In order to connect to an access point and join a wireless network, computers and devices must be equipped with wireless network adapters.

WI-FI VS. INTERNET

Wi-Fi and Internet are closely related and often used interchangeably, but there are important distinctions between the two. First and foremost, the Internet is a wide area network (WAN) that uses a series of protocols to transmit information between networks and devices around the world. Wi-Fi, on the other hand, is simply a means for connecting devices without cables.

It’s entirely possible to have a Wi-Fi connection with no Internet access if there is no modem or Internet service from an ISP. For this reason, the signal strength of a Wi-Fi network is not directly correlated to the Internet speed a user might experience when connected. It is also why isolated Internet connectivity issues are usually attributed to the user’s device or Wi-Fi network router as opposed to the ISP’s service.

What is a desktop Wi-Fi router?

The most common way for users to connect to the Internet wirelessly is with a desktop wireless (Wi-Fi) router. These routers look like small boxes with multiple short antennas to help broadcast the signal throughout a home or workplace. The farther a user is from the base Wi-Fi router, the weaker the signal. So multiple wireless routers, called range extenders, usually are placed throughout the workspace. Wi-Fi range extenders, placed in an array, boost or extend Internet coverage.

What is portable Wi-Fi hotspot?

A portable Wi-Fi hotspot is a mobile hotspot obtained through a cell phone carrier. It’s a small device that uses cellular towers that broadcast high-speed 3G or 4G broadband signals. Multiple devices, like iPads and laptops, can then connect wirelessly to the device, which in turn seamlessly connects to the Internet where ever you travel. Similar to a cell phone, the portable hotspot’s monthly cost is based on the data usage plan you select. A portable Wi-Fi hotspot is a more reliable way to access the Internet than searching for static public Wi-Fi hotspots.

Interesting facts about WI FI

• Most Internet users who have a broadband connection connect all their devices through WiFi, such as mobiles, laptops, and smart TVs.
• Free WiFi is provided by the government or internet provider at many public places where you can avail the internet for free with good speed.
• Indian Railways and Google together have provided free Wi-Fi facility at more than 5500 railway stations in India.
• Many people today proudly state that their home is a smart home, and WiFi has a huge role in making their home a smart home, no house can become smart without WiFi connectivity.
• Fastest WiFi internet in the world is available in South Korea, where people easily get WiFi internet speed of more than 100 Mbps.
• Today OTT platforms are becoming increasingly popular among people all over the world and the availability of WiFi is also a big reason behind their popularity.
• Initially, when people started using WiFi, it was not named WiFi, instead, people used the words Wave Lane, Dragon Fly, Flank Speed etc.

Types of Wireless Networks

There are basically three different types of wireless networks – WAN, LAN and PAN:

Wireless Wide Area Networks (WWAN): WWANs are created through the use of mobile phone signals typically provided and maintained by specific mobile phone (cellular) service providers. WWANs can provide a way to stay connected even when away from other forms of network access.

Wireless Local Area Network (WLAN): WLAN are wireless networks that use radio waves. The backbone network usually uses cables, with one or more wireless access points connecting the wireless users to the wired network. The range of a WLAN can be anywhere from a single room to an entire campus.

Wireless Personal Area Network (WPAN): WPANs are short-range networks that use Bluetooth technology. They are commonly used to interconnect compatible devices near a central location, such as a desk. A WPAN has a typical range of about 30 feet. Complete Guide to Wi-Fi Networking

The Advantages and Disadvantages of Wi-Fi

Advantages of Wi-Fi

• Convenience

– The wireless nature of such networks allow users to access network resources from nearly any convenient location within their primary networking environment
(a home or office). With the increasing saturation of laptop-style computers, this is particularly relevant.

• Mobility

– With the emergence of public wireless networks, users can access the internet even outside their normal work environment. Most chain coffee shops, for example, offer their customers a wireless connection to the internet at little or no cost.

• Productivity

– Users connected to a wireless network can maintain a nearly constant affiliation with their desired network as they move from place to place. For a business, this implies that an employee can potentially be more productive as his or her work can be accomplished from any convenient location.

• Deployment

– Initial setup of an infrastructure-based wireless network requires little more than a single access point. Wired networks, on the other hand, have the additional cost and complexity of actual physical cables being run to numerous locations (which can even be impossible for hard-to-reach locations within a building).

• Expandability

– Wireless networks can serve a suddenly-increased number of clients with the existing equipment. In a wired network, additional clients would require additional wiring.

• Cost

– Wireless networking hardware is at worst a modest increase from wired counterparts. This potentially increased cost is almost always more than outweighed by the savings in cost and labor associated to running physical cables.

Disadvantages of Wi-Fi

• Security

– To combat this consideration, wireless networks may choose to utilize some of the various encryption technologies available. Some of the more commonly utilized encryption methods, however, are known to have weaknesses that a dedicated adversary can compromise.

• Range

– The typical range of a common 802.11g network with standard equipment is on the order of tens of meters. While sufficient for a typical home, it will be insufficient in a larger structure. To obtain additional range, repeaters or additional access points will have to be purchased. Costs for these items can add up quickly.

• Reliability

– Like any radio frequency transmission, wireless networking signals are subject to a wide variety of interference, as well as complex propagation effects that are beyond the control of the network administrator.

• Speed

–  The speed on most wireless networks (typically 1-54 Mbps) is far slower than even the slowest common wired networks (100Mbps up to several Gbps). However, in specialized environments, the throughput of a wired network might be necessary.

Top 35 wi-fi related questions and answers

1. What is a link?

A link basically is the connection between two or more computers or devices. It can be anything depending on whether it is a physical connection or a wireless one. Physical links include cables, hubs, switches, etc and wireless links wireless access points, routers, etc.

2. What do you mean by a Node?

The point of intersection in a network is called a Node. Nodes can send or receive data/ information within a network. For example, if two computers are connected to form a network, there are 2 nodes in that network. Similarly, in case there are computers, there will be three nodes and so on. It is not necessary for a node to be a computer, it can be any communicating device such as a printer, servers, modems, etc.

3. What does a backbone network mean?

In any system, backbone is the most principal component that supports all other components. Similarly, in networking, a Backbone Network is a Network that interconnects various parts of the network to which it belongs and has a high-capacity connectivity infrastructure.

4. What is Network Topology?

The physical layout of the computer network is called as Network Topology. It gives the design of how all the devices are connected in a network.

5. Explain what is LAN?

A LAN or Local Area Network the network between devices that are located within a small physical location. It can be either wireless or wired. One LAN differs from another based on the following factors:

• Topology: The arrangement of nodes within the network
• Protocol: Refer to the rules for the transfer of data
• Media: These devices can be connected using optic fibers, twisted-pair wires, etc

6. What are Routers?

A router is some device that transfers the data packets within a network. It basically performs the traffic directing functions within a network. A data packet can be anything such as an email, a web page, etc. Routers are located at the place where two or more networks meet or the gateways.

Routers can either be stand-alone devices or virtual. Stand-alone routers are traditional devices where as virtual routers are actually software’s that act like physical ones.

Q7. What is a Point-to-Point Network?

A Point-to-Point network refers to a physical connection between two nodes. It can be between any device of a network such as a computer, printer, etc.

Q8. What do you mean by anonymous FTP?

An anonymous FTP is a way of allowing a user to access data that is public. The user does not need to identify himself to the server and has to log in as anonymous.

So in case you are asked to use anonymous ftp, make sure you add “anonymous” in place of your user id. Anonymous FTPs are very effective while distributing large files to a lot of people, without having to give huge numbers of usernames and password combinations.

Q9. What is the meaning of Network?

A network is a connection between different devices. These devices communicate with each other using physical or wireless connections. Physical connections include twisted pair cables, optic fibers, and coaxial cables. Wireless networks can be established with the help of waves such as radio waves infrared waves and microwaves
Networks basically serve many purposes such as:

• Sharing hardware devices such as printers, input devices, etc.
• Help in communications in many ways such as audios videos emails messages etc.
• Help in sharing data and information using virtual devices
• They also help sharing software that are installed on other devices

Q10. What is a UTP cable?

A UTP cable is a 100 ohms cable made up of copper. It consists of 2-1800 unshielded twisted pairs that are surrounded by a non-metallic case. These twists provide immunity to electrical noise and EMI.

Q11. What is the maximum length allowed for a UTP cable?

The maximum length allowed for a UTP cable is 100m. This includes 90 m of solid cabling and 10m of standard patch cable.

Q12. Explain what is HTTP and which port does it use?

HTTP or HyperText Transfer Protocol allows communication over the Internet. This protocol basically defines how messages are to be transmitted and formatted over the world wide web. HTTP is a TCP/ IP protocol and it uses port number 80.

Features of HTTP Protocol:

• It is connection-less
• Does not depend on the type of connecting media
• Stateless

Q13. What is NAT?

NAT stands for Network Address Translation. It deals with remapping one IP Address space with another by changing the IP headers of the packets that are being transmitted across a traffic routing device.

Q14. What is TCP?

TCP or Transmission Control Protocol is a connection-oriented protocol that establishes and maintains a connection between communicating devices until both of them are done exchanging messages. This protocol determines how application data can be broken down into packets that can be delivered over a network. It also sends and receives packets to and from the network layer and is in charge of flow control, etc.

Q15. Give a brief explanation about UDP?

UDP or the User Datagram Protocol is used to create low-latency and loss-tolerating communications between applications connected over the internet. UDP enables process-to-process communication and communicates via datagrams or messages.

Q16. What is RIP?

RIP (Routing Information Protocol) is a dynamic routing protocol. It makes use of hop count as its primary metric to find the best path between the source and the destination. It works in the application layer and has an AD (Administrative Distance) value of 120.

RIP (Routing Information Protocol) is a dynamic routing protocol. It makes use of hop count as its primary metric to find the best path between the source and the destination. It works in the application layer and has an AD (Administrative Distance) value of 120.

Q17. Explain what is a firewall?

A firewall is a network security system that is used to monitor and control network traffic based on some predefined rules. Firewalls are the first line of defense and establish barriers between the internal and external networks in order to avoid attacks from untrusted external networks. Firewalls can be either hardware, software, or sometimes both.

Q17. Explain what is NOS?

A Network Operating System (NOS) is an Operating System that is designed to support workstations, databases, personal computers, etc over a network. Some examples of NOS are MAC OS X, Linux, Windows Server 2008, etc. These Operating Systems provide various functionalities such as processor support, multiprocessing support, authentication, Web services, etc.

Q18. Explain what is Denial of Service (DoS)?

Denial of Service (DoS) is a kind of attack that prevents a legitimate user from accessing data over a network by a hacker or an attacker. The attacker floods the server with unnecessary requests in order to overload the server thereby preventing the legitimate users from accessing its services.

Q19. What is the full form of ASCII?

ASCII stands for American Standard Code for Information Interchange. It is a character encoding standard used in the electronic communication field. The ASCII codes basically represent text.

Q20. What is IEEE?

IEEE stands for Institute of Electrical and Electronics Engineer. It is the world’s largest technical professional society and is devoted to advancing innovation and technological excellence.

Q21. What is a MAC address and why is it required?

MAC or Media Access Control address is a computer’s unique number assigned to a Network Interface Controller (NIC). It is a 48-bit number that identifies each device on a network and is also referred to as the physical address. MAC addresses are used as a network address for communications within a network such as an Ethernet, Wi-Fi, etc.

Q22. What is piggybacking

During transmission of data packets in two-way communication, the receiver sends an acknowledgment (control frame or ACK) to the receiver after receiving the data packets. However, the receiver does not send the acknowledgment immediately, but, waits until its network layer passes in the next data packet. Then, the ACK is attached to the outgoing data frame. This process of delaying the ACK and attaching it to the next outgoing data frame is known as piggybacking.

Q23. What is OSPF?

OSPF stands for Open Shortest Path First. It is basically a routing protocol that is used to find the best path for packets that are being transmitted over interconnected networks.

Q24. What is Round Trip Time?

Round Trip Time or Round Trip Delay Time refers to the time taken for a signal to be sent and the ACK of that signal to be received.

Q25. What is DHCP?

DHCP or Dynamic Host Configuration Protocol is a network management protocol. It is used on the UDP/IP networks and it automatically assigns IP addresses to the devices on the network. This, in turn, reduces the need of a network admin to manually assign IP addresses thereby reducing errors.

Q26. Briefly explain what is ICMP?

ICMP stands for Internet Control Message Protocol and is a part of the Internet Protocol Suite. It is basically a supporting protocol to the Internet protocol and is used to send error messages and information regarding the success or failure of communication with another IP address. For example, if a service is not available an error is reported.

Q27. What is a Ping?

A ping is a computer program that is used to test the reachability of a host and check if can accept requests on an IP network. It works by sending an ICMP (Internet Control Message Protocol) Echo to some computer on the network and waits for a reply from it. It can also be used for troubleshooting.

Q28. What are the advantages of optic fibers?

Optic fibers have a number of advantages such as:

• Greater bandwidth than other metal cables
• Low power loss allows longer transmission distances
• Optic cables are immune to electromagnetic interference
• Lesser production rates
• Thin and light
• The optical fiber cable is difficult to tap

Q29. What is a client/ server network?

A client/ server network is a network where one computer behaves as a server to the other computers. The server is usually more powerful than the clients and serves the clients.

Q30.  In a network that contains two servers and twenty workstations, where is the best place to install an Anti-virus program?

The best solution is to install anti-virus on all the computers in the network. This will protect each device from the other in case some malicious user tries to insert a virus into the servers or legitimate users.

Q31. What do you mean by Ethernet?

Ethernet is a network technology used in LAN, MAN and WAN that connects devices using cables for the transmission of data. It provides services on the Physical and Data Link layers of the OSI Model

Q42.WhaQ42.What is SLIP?t is SLIP?

SLIP stands for Serial Line Internet Protocol which allows a user to access the internet using the modem.

Q33. Briefly explain what is tunnel mode?

Tunnel mode is used to encrypt the whole IP packet including the headers and the payload. It is basically used in a Site-to-Site VPN to secure communications between security gateways, firewalls, etc.

Q34. What do you mean by IPv6?

IPv6 stands for Internet Protocol version 6 and is the latest version of the Internet Protocol. The IP address length is 128 bits which resolve the issue of approaching shortage of network addresses.

Q45. Explain the RSA algorithm briefly.

RSA is a cryptosystem used to secure data transmission named after Ron Rivest, Adi Shamir and Len Adleman. This algorithm has a public key for encryption while the decryption key is kept secure or private. The encryption key is created using