Difference between 2G,3G,4G,VoLTE

Difference Between 2G,3G,4G and VoLTE

2G 

It is short for Second Generation, which is wireless telephone technology. This 2G is well known for GSM in commercial standard. Which is launched in the Country Finland. In this the mobile phone communication were digitally encrypted, which includes SMS Text messages. 2G technology enabled its services to various cell phones which is compatible with 2G Network support such as Text Messages,Picture messages, and MMS(Multimedia messages). All text messages sent through 2G network is digitally encrypted.

3G

It is short for Third Generation, which is wireless telecommunication technology. It transmit the applications in wireless voice,mobile internet access, fixed wireless internet access, video calls, and mobile TV. It provides the data transfer of at least   200 kbits/s. which is higher than the data providing by 2G.

4G

It is shorth for Fourth generation, which is wireless mobile telecommunication technology, it is most advanced then the 2G and 3G. It means that the technology has improved lot. it provides the data speed at 100 megabits per sec for high mobility communications and 1 gigabit per sec for low mobility communication.

VoLTE 

It is short for Voice Over Long-Term Evolution,it is mean for its high speed wireless communication for mobile phones. It transfer mobile data in terms of 4G technology. In this all our voice calls are transferred via VoLTE technology.

What is PoE

Power Over Ethernet

Power over Ethernet or PoE technology describes a system to transmit electrical power, along with data, to remote devices over standard twisted-pair cable in an Ethernet network. This technology is useful for powering IP telephones, wireless LAN access points, webcams, Ethernet hubs, computers, and other appliances where it would be inconvenient or infeasible to supply power separately. 

What is OFC

 Fibre Optic Cables

In 1954 a major breakthrough in technology occurred in the development of fibre optic cables. The principle of fibre optic cable was based on the total internal reflection of light. Light can be conducted along a curved glass rod due to multiple total internal reflections at the walls of the rod. Light would enter at one end of the fibre and emerge at the other end after numerous internal reflections with virtually all of its strength. 

Now a day there is two types of light cable available in market. 

1. Fiber Optic cable 

2. Liquid crystal Gel cable 

Optic cables 
These cables are made up of a bundle of optical fibres glass thread swaged at both ends. The fibre size used is usually between 10 to 25 mm in diameter. They have a very high quality of optical transmission, but are fragile. In fact, progressively as they are used, some optical fibres break. The loss of optical fibres may be seen when one end of the cable is viewed in daylight. The broken fibres are seen as black spots 

Gel cables 

These cables are made up of a sheath that is filled with a clear optical gel. (Liquid crystal). Theoretically they are capable of transmitting 30% more light than optic fibres. Swaged at both ends by quartz. Due to more light and better color temperature transmission this cable is recommended in those circumstances where documentation (movie, photography or TV) is performed. They pose three problems: 

· The quartz swaging at the ends is extremely fragile, especially when the cable is hot. The slightest shock, on a bench for example, can cause the quartz end to crack and thus cause a loss in the transmission of the light; 

· These cables transmit more heat than optical fibre cables. 

· These cables are made more rigid by a metal sheath, which makes them more difficult to maintain and to store. 

What is PING commend in networking

PING 

The ping command is used to see if a remote address is accessible. It is also used to see how long it takes to communicate over the network to the remote address. By pinging an address, you can tell if the network is down or if it is unusually slow. 

For example, to find out how long it takes for your computer to connect to www.google.com, you can type this in the command window: 
ping google.com 

And the response looks something like this
Pinging google.com [64.233.187.99] with 32 bytes of data: 

Reply from 64.233.187.99: bytes=32 time=42ms TTL=242 
Reply from 64.233.187.99: bytes=32 time=38ms TTL=242 
Reply from 64.233.187.99: bytes=32 time=36ms TTL=243 
Reply from 64.233.187.99: bytes=32 time=38ms TTL=243 

Ping statistics for 64.233.187.99: 
Packets: Sent = 4, Received = 4, Lost = 0 (0% loss), 
Approximate round trip times in milli-seconds: 
Minimum = 36ms, Maximum = 42ms, Average = 38ms

What is mean by ADSL

What is mean by ADSL 

 Asymmetric Digital Subscriber Line (ADSL) is one form of the Digital Subscriber Line technology, a data communications technology that enables faster data transmission over copper telephone lines than a conventional voiceband modem can provide. It does this by utilizing frequencies that are not used by a voice telephone call.[1] A splitter, or DSL filter, allows a single telephone connection to be used for both ADSL service and voice calls at the same time. ADSL can generally only be distributed over short distances from the central office, typically less than 4 kilometres (2 mi),[2] but has been known to exceed 8 kilometres (5 mi) if the originally laid wire gauge allows for farther distribution. In 2005, the ability to transmit copper ADSL/DSL services over a fiber optic cable became possible by utilizing the RLH ADSL/DSL fiber optic link, providing distances from one point to the opposite end of the system of more than 30 miles.


What is mean by DSL

Digital subscriber line (DSL)
technology that exploits unused frequencies on copper telephone lines to transmit traffic typically at multi-megabit speeds. DSL can allow voice and high-speed data to be sent simultaneously over the same line. Because the service is 'always available,' end-users don't need to dial in or wait for call set-up. With DSL you are wired for speed.

Difference Between 32 bit and 64 bit processor.

32 bit and 64 bit Processor.

A 32 bit processor handles data in 32 bit chunks. A 64 bit processor handles data in 64 bit chunks. As a result, a 64 bit processor can handle twice as much data in one cycle as a 32 bit processor. 

Cores: Cores are the number of processors. A single core system has one CPU which has one core. 

A dual core system has one CPU with 2 cores in it. 

So a 64 bit processor with 2 cores can handle 4 times as much data in one cycle as a single core 32 bit processor. 

It used to be that in order to have multiple cores you had to have multiple physical CPUs. Most CPUs anymore actually have multiple cores on one physical CPU . This allowed for increased performance without having to increase the speed of the processors as the technology was running into physical limits of frequency (ghz) and processors could not be made to go much faster with current technology. 

You can use a 32 bit operating system on a 64 bit processor and many machines do. The primary reason to use a 64 bit operating system at this point is that a 32 bit operating system can only address about 3.5 gigs of RAM and a 64bit operating system can address TBs of RAM, far more than is currently available in personal computers.

What is TCP/IP in networking

TCP/IP(Transport Control Protocol / Internet Protocol)


TCP/IP stands for Transport Control Protocol / Internet Protocol suite. TCP/IP was created in 1983 to replace NCP, because TCP/IP can successfully switch packets from all shapes and sizes and varieties of networks. Therfore TCP/IP has become the backbone of the Internet and its composite LANs and WANs due to it's ability to switch packets from computer systems on any network to another network, regardless of network peculiarities, operating system differences and other packet differences. The TCP/IP protocol suite refers to several separate protocols that computers use to transfer data across the Internet, below are four of the most commonly used TCP/IP protocols, 
Components of TCP/IP 

IP - The Internet Protocol is a network layer protocol that moves data between host computers. 
TCP - The Transport Control Protocol is a transport layer protocol that moves multiple packet data between applications. 
UDP - The User Datagram Protocol is a transport layer protocol like TCP but is less complex and reliable than TCP. 
ICMP - The Internet Control Message Protocol carries network error messages and other network software requirements. 

Computer networks use a standard connection model which is called ISO/OSI. The ISO/OSI model has seven layer which the TCP/IP protocol suite has implemented, below is a list of the ISO/OSI layers and the TCP/IP counterpart layers, 
ISO/OSI Layer

Application 
Presentation 
Session 
Transport 
Network 
Data-Link 
Physical


Function 

file transfers, email, file servers,data formatting, encryption 
negotiation and establishment of a connection end to end data provision routing of packets transfer of addressable units of frames and error checking transmission of binary data over a communications network TCP/IP Protocols TFTP, BOOTP, SNMP, FTP, SMTP, MIME,TCP, UDP,IP, ICMP, RIP, OSPF, BGP, IGMP 
SLIP, CSLIP, PPP, ARP, RASP, MTU,ISO, 2110, IEEE, 802, IEEE 802.2 

Transport Communication Protocol / Internet Protocol 
TCP/IP is a "communications protocol" 

An agreement to speak a language 
The definition of the language 

Sample TCP/IP address 

200.210.220.5 

Classes of IP Address

 

CACHE MEMORY

Cache memory is random access memory (RAM).Which is a computer microprocessor can access more quickly than it can access regular RAM. As the microprocessor processes data, it looks first in the cache memory and if it finds the data there (from a previous reading of data), it does not have to do the more time-consuming reading of data from larger memory. 
Cache memory is sometimes described in levels of closeness and accessibility to the microprocessor. An L1 cache is on the same chip as the microprocessor. (For example, the PowerPC 601 processor has a 32 kilobyte level-1 cache built into its chip.) L2 is usually a separate static RAM (SRAM) chip. The main RAM is usually a dynamic RAM (DRAM) chip. 

In addition to cache memory, one can think of RAM itself as a cache of memory for hard disk storage since all of RAM's contents come from the hard disk initially when you turn your computer on and load the operating system (you are loading it into RAM) and later as you start new applications and access new data. RAM can also contain a special area called a disk cache that contains the data most recently read in from the hard disk

TYPES OF CACHE

1.Memory cache
2.Disk cache

The two main types of cache are: memory cache and disk cache. Memory cache is a portion on memory of high-speed static RAM (SRAM) and is effective because most programs access the same data or instructions over and over. By keeping as much of this information as possible in SRAM, the computer avoids accessing the slower DRAM.
Like memory caching, disk caching is used to access commonly accessed data. However, instead of using high-speed SRAM, a disk cache uses conventional main memory. The most recently accessed data from the disk is stored in a memory buffer. When a program needs to access data from the disk, it first checks the disk cache to see if the data is there. 

Another type of cache is known as "Internet browser cache" also known as "Temporary Internet Files". Internet cache is used to help improve how fast data is opened while browsing the Internet. In most cases, each time a web page is opened, it is sent to your browser's temporary cache on your hard disk drive. If that page is accessed again and has not been modified, the browser will open the page from your cache instead of downloading the page again. This saves users a lot of time, especially if that user is using a modem, and can also help save the web page owner on bandwidth. 

HARD DISK AND MEMORY

HARD DISK AND MEMORY - HOW IT WORKS

 

Memory is nothing but a Basic electronic part and stores some digital information in it. In Hard disk, the info are stored as magnetic field. Memory is simply what you are focusing on at the moment. It isn't as large as the hard drive, which can save much much more, but it is much faster which is why it is practical for only what you are currently using. You can almost think of them as short term and long term memory. Long term (hard drive) is the stuff that has been stored - archived if you will - for a time in the future, where as short term (memory) is for what you are doing right now. You can recall the information from long term and place it in your short term to use, but when you are finished, you push it right back to long term.

On a Hard Disk Drive, there is an index where the computer stores the location of saved files on the drive. When you try to access information, your processor sends a command where the HDD looks up the location of the information and then skips to that point on the disk. It then reads that information which is stored in the form of positive and negative charges, representing off and on or 0's and 1's. This code is called binary and is the language of computers.

The information it retrieves is then passed on to the memory (RAM) which is the information you are currently using. RAM is much faster than your HDD and thus is used for current tasks. While you are using the item it is stored in the RAM. When you save save something, it runs back to the HDD where it writes it on the disk and then registers where it was saved in the index. 

TYPES OF HARD DISK                                                   

Hard disks are generally accessed over one of a number of bus types, including 

ATA (IDE, EIDE) 

Serial ATA (SATA) 

SCSI

SAS

IEEE 1394

USB, and

and Fibre Channel.

  

 

NIC CARD- Network card

NIC CARD ( NETWORK INTERFACE CARD)















1. A Network Interface Card is what communicates with the computer uses to communicate over a network. Sometimes a NIC (said "nick") is integrated into your computer's motherboard or as a slot card. Most computers will come with a NIC. If not, they are easy to find at Staples or OfficeMax for purchase. 
2. 10/100 Mbps Ethernet Port are the speeds that your NIC is able to work at. A NIC with this configuration can work at 10 Mbps or 100 Mbps. 
3. An RJ-45 denotes the type of connector that is compatible with the NIC. An RJ-45 connector looks like a big phone connector. Go look at your phone connector. That is what is called an RJ-11 connector. Now look at the socket the phone cord plugs into either the phone or the wall. An RJ-45 connector is twice as big. So if the connector on the back of your NIC looks like a big phone plug could fit into it, that's what you need. 

GRAPHI CARD

GRAPHI CARD ( VIDEO CARD ) 

 

Graphic Card is a circuit board that enables a computer to display screen information. 

A graphics card's job is complex, but its principles and components are easy to understand. In this article, we will look at the basic parts of a video card and what they do. We'll also examine the factors that work together to make a fast, efficient graphics card. 

A graphics card works along the same principles. The CPU, working in conjunction with software applications, sends information about the image to the graphics card. The graphics card decides how to use the pixels on the screen to create the image. It then sends that information to the monitor through a cable. 

The graphics card accomplishes this task using four main components: 
* A motherboard connection for data and power 
* A processor to decide what to do with each pixel on the screen 
* Memory to hold information about each pixel and to temporarily store completed pictures 
* A monitor connection so you can see the final result 

It is same as Video adapter: A board that plugs into a personal computer to give it display capabilities. The display capabilities of a computer, however, depend on both the logical circuitry (provided in the video adapter) and the display monitor. A monochrome monitor, for example, cannot display colors no matter how powerful the video adapter. 

What is RAM ( Random Access Memory )

RAM ( Random Access Memory )    

















RAM can be compared to a person's short-term memory and the hard disk to the long-term memory. The short-term memory focuses on work at hand, but can only keep so many facts in view at one time. If short-term memory fills up, your brain sometimes is able to refresh it from facts stored in long-term memory. 

RAM (random access memory) is the place in a computer where the operating system, application programs, and data in current use are kept so that they can be quickly reached by the computer's processor. RAM is much faster to read from and write to than the other kinds of storage in a computer, the hard disk, floppy disk, and CD-ROM. However, the data in RAM stays there only as long as your computer is running. When you turn the computer off, RAM loses its data. When you turn your computer on again, your operating system and other files are once again loaded into RAM, usually from your hard disk.

There are 2 types of RAM-
1) Static RAM (used Before)
2) DDR RAM Dynamic RAM (used now a days)

What is SMPS

SMPS(switched-mode power supply)

SMPS means Switch Mode Power Supply.As the name suggests it is used to switch the Alternating Current(AC) voltage into Direct current (DC) voltage which is required for our computer systems to work.It is placed inside the C.P.U of our computer and from this SMPS connections are given to the CD/DVD drive,Hard disk and to all parts of the computer. 

Function of SMPS is similar to the transformers that are seen on the streets near our houses.These transformers also convert AC into DC voltage and supply it to our houses.But we cannot place a transformer in our computers as space occupied is too large.So,SMPS are introduced in the place of transformers.It is very efficient and very low heat is produced by this. 

in general it is highly reliable and can guarantee you an efficient work up to 5 years.But if there is any fluctuation in your power line that will directly effect your SMPS and it may be damaged. 

SMPS can also be classified into four types according to the input and output waveforms, as follows. 

AC in, DC out: rectifier, off-line converter 
DC in, DC out: voltage converter, or current converter, or DC to DC converter 
AC in, AC out: frequency changer, cycloconverter 
DC in, AC out: inverter 
AC and DC are abbreviations for alternating current and direct current. 


Switched-mode PSUs in domestic products such as personal computers often have universal inputs, meaning that they can accept power from most mains supplies throughout the world, with frequencies from 50 Hz to 60 Hz and voltages from 100 V to 240 V (although a manual voltage "range" switch may be required). 

In the case of TV sets, for example, one can test the excellent regulation of the power supply by using a variac. For example, in some models made by Philips, the power supply starts when the voltage reaches around 90 volts. From then, one can change the voltage with the variac, and go as low as 40 volts and as high as 260, and the image will show absolutely no alterations.

Interview Question and answers-Hardware and Networking

Q. What is a LAN?

LAN is short for Local Area Network. It refers to the connection between computers and other network devices that are located within a small physical location.

Q. What is a node?

A node refers to a point or joint where a connection takes place. It can be computer or device that is part of a network. Two or more nodes are needed in order to form a network connection.

Q. What are routers?

Routers can connect two or more network segments. These are intelligent network devices that store information in its routing table such as paths, hops and bottlenecks. With this info, they are able to determine the best path for data transfer. Routers operate at the OSI Network Layer.

Q. What is point to point link?

It refers to a direct connection between two computers on a network. A point to point connection does not need any other network devices other than connecting a cable to the NIC cards of both computers.

Q.What is anonymous FTP?

Anonymous FTP is a way of granting user access to files in public servers. Users that are allowed access to data in these servers do not need to identify themselves, but instead log in as an anonymous guest.

Q.What is subnet mask?

A subnet mask is combined with an IP address in order to identify two parts: the extended network address and the host address. Like an IP address, a subnet mask is made up of 32 bits.

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

A single segment of UTP cable has an allowable length of 90 to 100 meters. This limitation can be overcome by using repeaters and switches.

Q. What is data encapsulation?

Data encapsulation is the process of breaking down information into smaller manageable chunks before it is transmitted across the network. It is also in this process that the source and destination addresses are attached into the headers, along with parity checks.

Q. Describe Network Topology

Network Topology refers to the layout of a computer network. It shows how devices and cables are physically laid out, as well as how they connect to one another.

Q. What is VPN?

VPN means Virtual Private Network, a technology that allows a secure tunnel to be created across a network such as the Internet. For example, VPNs allow you to establish a secure dial-up connection to a remote server

Q. Briefly describe NAT.

NAT is Network Address Translation. This is a protocol that provides a way for multiple computers on a common network to share single connection to the Internet.

Q. What is the job of the Network Layer under the OSI reference model?

The Network layer is responsible for data routing, packet switching and control of network congestion. Routers operate under this layer.

Q. How does a network topology affect your decision in setting up a network?

Network topology dictates what media you must use to interconnect devices. It also serves as basis on what materials, connector and terminations that is applicable for the setup.

Q. What is RIP?

RIP, short for Routing Information Protocol is used by routers to send data from one network to another. It efficiently manages routing data by broadcasting its routing table to all other routers within the network. It determines the network distance in units of hops.

Q. What are different ways of securing a computer network?

There are several ways to do this. Install reliable and updated anti-virus program on all computers. Make sure firewalls are setup and configured properly. User authentication will also help a lot. All of these combined would make a highly secured network.

Q. What is NIC?

NIC is short for Network Interface Card. This is a peripheral card that is attached to a PC in order to connect to a network. Every NIC has its own MAC address that identifies the PC on the network.

Q. What is WAN?

WAN stands for Wide Area Network. It is an interconnection of computers and devices that are geographically dispersed. It connects networks that are located in different regions and countries.

Q. What is the importance of the OSI Physical Layer?

The physical layer does the conversion from data bits to electrical signal, and vice versa. This is where network devices and cable types are considered and setup.

Q. How many layers are there under TCP/IP?

There are four layers: the Network Layer, Internet Layer, Transport Layer and Application Layer.

Q. What are proxy servers and how do they protect computer networks?

Proxy servers primarily prevent external users who identifying the IP addresses of an internal network. Without knowledge of the correct IP address, even the physical location of the network cannot be identified. Proxy servers can make a network virtually invisible to external users.

Q. What is the function of the OSI Session Layer?

This layer provides the protocols and means for two devices on the network to communicate with each other by holding a session.  This includes setting up the session, managing information exchange during the session, and tear-down process upon termination of the session.

Q. What is a Link?

A link refers to the connectivity between two devices. It includes the type of cables and protocols used in order for one device to be able to communicate with the other.

Q. What are the layers of the OSI reference model?

There are 7 OSI layers: Physical Layer, Data Link Layer, Network Layer, Transport Layer, Session Layer, Presentation Layer and Application Layer.

Q. What is backbone network?

A backbone network is a centralized infrastructure that is designed to distribute different routes and data to various networks. It also handles management of bandwidth and various channels.

Q. What is the importance of implementing a Fault Tolerance System? Are there limitations?

A fault tolerance system ensures continuous data availability. This is done by eliminating a single point of failure. However, this type of system would not be able to protect data in some cases, such as in accidental deletions.

Q. What does 10Base-T mean?

The 10 refers to the data transfer rate, in this case is 10Mbps. The word Base refers to base band, as oppose to broad band. T means twisted pair, which is the cable used for that network.

Q. What is a private IP address?

Private IP addresses are assigned for use on intranets. These addresses are used for internal networks and are not routable on external public networks. These ensures that no conflicts are present among internal networks while at the same time the same range of private IP addresses are reusable for multiple intranets since they do not “see” each other.

Q. What is NOS?

NOS, or Network Operating System, is specialized software whose main task is to provide network connectivity to a computer in order for it to be able to communicate with other computers and connected devices.

Q. What is DoS?

DoS, or Denial-of-Service attack, is an attempt to prevent users from being able to access the internet or any other network services. Such attacks may come in different forms and are done by a group of perpetuators. One common method of doing this is to overload the system server so it cannot anymore process legitimate traffic and will be forced to reset.

Q. What is OSI and what role does it play in computer networks?

OSI (Open Systems Interconnect) serves as a reference model for data communication. It is made up of 7 layers, with each layer defining a particular aspect on how network devices connect and communicate with one another. One layer may deal with the physical media used, while another layer dictates how data is actually transmitted across the network.

Q. What is the purpose of cables being shielded and having twisted pairs?

The main purpose of this is to prevent crosstalk. Crosstalks are electromagnetic interferences or noise that can affect data being transmitted across cables.

Q. What is the advantage of address sharing?

By using address translation instead of routing, address sharing provides an inherent security benefit. That’s because host PCs on the Internet can only see the public IP address of the external interface on the computer that provides address translation and not the private IP addresses on the internal network.

Q. What are MAC addresses?

MAC, or Media Access Control, uniquely identifies a device on the network. It is also known as physical address or Ethernet address. A MAC address is made up of 6-byte parts.

Q. What is the equivalent layer or layers of the TCP/IP Application layer in terms of OSI reference model?

The TCP/IP Application layer actually has three counterparts on the OSI model: the Session layer, Presentation Layer and Application Layer.

Q. How can you identify the IP class of a given IP address?

By looking at the first octet of any given IP address, you can identify whether it’s Class A, B or C. If the first octet begins with a 0 bit, that address is Class A. If it begins with bits 10 then that address is a Class B address. If it begins with 110, then it’s a Class C network.

Q. What is the main purpose of OSPF?

OSPF, or Open Shortest Path First, is a link-state routing protocol that uses routing tables to determine the best possible path for data exchange.

Q. What are firewalls?

Firewalls serve to protect an internal network from external attacks. These external threats can be hackers who want to steal data or computer viruses that can wipe out data in an instant. It also prevents other users from external networks from gaining access to the private network.

Q. Describe star topology

Star topology consists of a central hub that connects to nodes. This is one of the easiest to setup and maintain.

Q. What are gateways?

Gateways provide connectivity between two or more network segments. It is usually a computer that runs the gateway software and provides translation services. This translation is a key in allowing different systems to communicate on the network.

Q. What is the disadvantage of a star topology?

One major disadvantage of star topology is that once the central hub or switch get damaged, the entire network becomes unusable.

Q. What is SLIP?

SLIP, or Serial Line Interface Protocol, is actually an old protocol developed during the early UNIX days. This is one of the protocols that are used for remote access.

Q. Give some examples of private network addresses.

10.0.0.0 with a subnet mask of 255.0.0.0
172.16.0.0 with subnet mask of 255.240.0.0
192.168.0.0 with subnet mask of 255.255.0.0

Q. What is tracert?

Tracert is a Windows utility program that can used to trace the route taken by data from the router to the destination network. It also shows the number of hops taken during the entire transmission route.

Q. What are the functions of a network administrator?

A network administrator has many responsibilities that can be summarize into 3 key functions: installation of a network, configuration of network settings, and maintenance/troubleshooting of networks.

Q. Describe at one disadvantage of a peer to peer network.

When you are accessing the resources that are shared by one of the workstations on the network, that workstation takes a performance hit.

Q. What is Hybrid Network?

A hybrid network is a network setup that makes use of both client-server and peer-to-peer architecture.

Q. What is DHCP?

DHCP is short for Dynamic Host Configuration Protocol. Its main task is to automatically assign an IP address to devices across the network. It first checks for the next available address not yet taken by any device, then assigns this to a network device.

Q. What is the main job of the ARP?

The main task of ARP or Address Resolution Protocol is to map a known IP address to a MAC layer address.

Q. What is TCP/IP?

TCP/IP is short for Transmission Control Protocol / Internet Protocol. This is a set of protocol layers that is designed to make data exchange possible on different types of computer networks, also known as heterogeneous network.

Q. What protocol can be applied when you want to transfer files between different platforms, such between UNIX systems and Windows servers?

Use FTP (File Transfer Protocol) for file transfers between such different servers. This is possible because FTP is platform independent.

Q. What is the use of a default gateway?

Default gateways provide means for the local networks to connect to the external network. The default gateway for connecting to the external network is usually the address of the external router port.

Q. One way of securing a network is through the use of passwords. What can be considered as good passwords?

Good passwords are made up of not just letters, but by combining letters and numbers. A password that combines uppercase and lowercase letters is favorable than one that uses all upper case or all lower case letters. Passwords must be not words that can easily be guessed by hackers, such as dates, names, favorites, etc. Longer passwords are also better than short ones.

Q. What is the proper termination rate for UTP cables?

The proper termination for unshielded twisted pair network cable is 100 ohms.

Q. What is netstat?

Netstat is a command line utility program. It provides useful information about the current TCP/IP settings of a connection.

Q. What is the number of network IDs in a Class C network?

For a Class C network, the number of usable Network ID bits is 21. The number of possible network IDs is 2 raised to 21 or 2,097,152. The number of host IDs per network ID is 2 raised to 8 minus 2, or 254.

Q. What happens when you use cables longer than the prescribed length?

Cables that are too long would result in signal loss. This means that data transmission and reception would be affected, because the signal degrades over length.

Q. What common software problems can lead to network defects?

Software related problems can be any or a combination of the following:
– client server problems
– application conflicts
– error in configuration
– protocol mismatch
– security issues
– user policy and rights issues

Q. What is ICMP?

ICMP is Internet Control Message Protocol. It provides messaging and communication for protocols within the TCP/IP stack. This is also the protocol that manages error messages that are used by network tools such as PING.

60) What is Ping?

Ping is a utility program that allows you to check connectivity between network devices on the network. You can ping a device by using its IP address or device name, such as a computer name.

Q. What is peer to peer?

Peer to peer are networks that does not reply on a server. All PCs on this network act as individual workstations.

Q. What is DNS?

DNS is Domain Name System. The main function of this network service is to provide host names to TCP/IP address resolution.

Q. What advantages does fiber optics have over other media?

One major advantage of fiber optics is that is it less susceptible to electrical interference. It also supports higher bandwidth, meaning more data can be transmitted and received. Signal degrading is also very minimal over long distances.

Q. What is the difference between a hub and a switch?

A hub acts as a multiport repeater. However, as more and more devices connect to it, it would not be able to efficiently manage the volume of traffic that passes through it. A switch provides a better alternative that can improve the performance especially when high traffic volume is expected across all ports.

Q. What are the different network protocols that are supported by Windows RRAS services?

There are three main network protocols supported: NetBEUI, TCP/IP, and IPX.

Q. What are the maximum networks and hosts in a class A, B and C network?

For Class A, there are 126 possible networks and 16,777,214 hosts
For Class B, there are 16,384 possible networks and 65,534 hosts
For Class C, there are 2,097,152 possible networks and 254 hosts

Q. What is the standard color sequence of a straight-through cable?

orange/white, orange, green/white, blue, blue/white, green, brown/white, brown.

Q. What protocols fall under the Application layer of the TCP/IP stack?

The following are the protocols under TCP/IP Application layer: FTP, TFTP, Telnet and SMTP.

Q. You need to connect two computers for file sharing. Is it possible to do this without using a hub or router?

Yes, you can connect two computers together using only one cable. A crossover type cable can be use in this scenario. In this setup, the data transmit pin of one cable is connected to the data receive pin of the other cable, and vice versa.

Q. What is ipconfig?

Ipconfig is a utility program that is commonly used to identify the addresses information of a computer on a network. It can show the physical address as well as the IP address.

Q. What is the difference between a straight-through and crossover cable?

A straight-through cable is used to connect computers to a switch, hub or router. A crossover cable is used to connect two similar devices together, such as a PC to PC or Hub to hub.

Q. What is client/server?

Client/server is a type of network wherein one or more computers act as servers. Servers provide a centralized repository of resources such as printers and files. Clients refers to workstation that access the server.

Q. Describe networking.

Networking refers to the inter connection between computers and peripherals for data communication. Networking can be done using wired cabling or through wireless link.

Q. When you move the NIC cards from one PC to another PC, does the MAC address gets transferred as well?

Yes, that’s because MAC addresses are hard-wired into the NIC circuitry, not the PC. This also means that a PC can have a different MAC address when the NIC card was replace by another one.

Q. Explain clustering support

Clustering support refers to the ability of a network operating system to connect multiple servers in a fault-tolerant group. The main purpose of this is the in the event that one server fails, all processing will continue on with the next server in the cluster.

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

An anti-virus program must be installed on all servers and workstations to ensure protection. That’s because individual users can access any workstation and introduce a computer virus when plugging in their removable hard drives or flash drives.

Q. Describe Ethernet.

Ethernet is one of the popular networking technologies used these days. It was developed during the early 1970s and is based on specifications as stated in the IEEE. Ethernet is used in local area networks.

Q. What are some drawbacks of implementing a ring topology?

In case one workstation on the network suffers a malfunction, it can bring down the entire network. Another drawback is that when there are adjustments and reconfigurations needed to be performed on a particular part of the network, the entire network has to be temporarily brought down as well.

Q. What is the difference between CSMA/CD and CSMA/CA?

CSMA/CD, or Collision Detect, retransmits data frames whenever a collision occurred. CSMA/CA, or Collision Avoidance, will first broadcast intent to send prior to data transmission.

Q. What is SMTP?

SMTP is short for Simple Mail Transfer Protocol. This protocol deals with all Internal mail, and provides the necessary mail delivery services on the TCP/IP protocol stack.

Q. What is multicast routing?

Multicast routing is a targeted form of broadcasting that sends message to a selected group of user, instead of sending it to all users on a subnet.

Q. What is the importance of Encryption on a network?

Encryption is the process of translating information into a code that is unreadable by the user. It is then translated back or decrypted back to its normal readable format using a secret key or password. Encryption help ensure that information that is intercepted halfway would remain unreadable because the user has to have the correct password or key for it.

Q. How are IP addresses arranged and displayed?

IP addresses are displayed as a series of four decimal numbers that are separated by period or dots. Another term for this arrangement is the dotted decimal format. An example is 192.168.101.2

Q. Explain the importance of authentication.

Authentication is the process of verifying a user’s credentials before he can log into the network. It is normally performed using a username and password. This provides a secure means of limiting the access from unwanted intruders on the network.

Q. What do mean by tunnel mode?

This is a mode of data exchange wherein two communicating computers do not use IPSec themselves. Instead, the gateway that is connecting their LANs to the transit network creates a virtual tunnel that uses the IPSec protocol to secure all communication that passes through it.

Q. What are the different technologies involved in establishing WAN links?

Analog connections – using conventional telephone lines; Digital connections – using digital-grade telephone lines; switched connections – using multiple sets of links between sender and receiver to move data.

Q. What is one advantage of mesh topology?

In the event that one link fails, there will always be another available. Mesh topology is actually one of the most fault-tolerant network topology.

Q. When troubleshooting computer network problems, what common hardware-related problems can occur?

A large percentage of a network is made up of hardware. Problems in these areas can range from malfunctioning hard drives, broken NICs and even hardware startups. Incorrectly hardware configuration is also one of those culprits to look into.

Q. What can be done to fix signal attenuation problems?

A common way of dealing with such a problem is to use repeaters and hub, because it will help regenerate the signal and therefore prevent signal loss. Checking if cables are properly terminated is also a must.

Q. How does dynamic host configuration protocol aid in network administration?

Instead of having to visit each client computer to configure a static IP address, the network administrator can apply dynamic host configuration protocol to create a pool of IP addresses known as scopes that can be dynamically assigned to clients.

Q. Explain profile in terms of networking concept?

Profiles are the configuration settings made for each user. A profile may be created that puts a user in a group, for example.

Q. What is sneakernet?

Sneakernet is believed to be the earliest form of networking wherein data is physically transported using removable media, such as disk, tapes.

Q. What is the role of IEEE in computer networking?

IEEE, or the Institute of Electrical and Electronics Engineers, is an organization composed of engineers that issues and manages standards for electrical and electronic devices. This includes networking devices, network interfaces, cablings and connectors.

Q. What protocols fall under the TCP/IP Internet Layer?

There are 4 protocols that are being managed by this layer. These are ICMP, IGMP, IP and ARP.

Q. When it comes to networking, what are rights?

Rights refer to the authorized permission to perform specific actions on the network. Each user on the network can be assigned individual rights, depending on what must be allowed for that user.

Q. What is one basic requirement for establishing VLANs?

A VLAN is required because at switch level there is only one broadcast domain, it means whenever new user is connected to switch this information is spread throughout the network. VLAN on switch helps to create separate broadcast domain at  switch level. It is used for security purpose.

Q. What is IPv6?

IPv6 , or Internet Protocol version 6, was developed to replace IPv4. At present, IPv4 is being used to control internet traffic, butis expected to get saturated in the near future. IPv6 was designed to overcome this limitation.

Q. What is RSA algorithm?

RSA is short for Rivest-Shamir-Adleman algorithm. It is the most commonly used public key encryption algorithm in use today.

Q. What is mesh topology?

Mesh topology is a setup wherein each device is connected directly to every other device on the network. Consequently, it requires that each device have at least two network connections.

Q. what is the maximum segment length of a 100Base-FX network?

The maximum allowable length for a network segment using 100Base-FX is 412 meters. The maximum length for the entire network is 5 kilometers.