Interview Questions.

Q1. Define IP Spoofing?

Ans: Sending messages through intruder to a laptop gadget with an IP address that shows the message is despatched from a trusted host, for gaining unauthorized get entry to to computer systems. The hacker/intruder first make use of a diffusion of techniques for locating an IP deal with of a trusted host. Later he modifies the packet headers, with a purpose to provide an phantasm that the packets are sent from the host.

Q2. Define Cabir Worm?

Ans: Cabir malicious program is one of the malicious software program, commonly referred as malware. It utilizes Bluetooth technology for sending itself to any other in addition susceptible device. As it's far self-replicative, is it categorized as a bug.

Cabir worms are presently influences cell smartphone which uses the Symbian Series 60 User Interface Platform and characteristic Bluetooth wi-fi generation.

Q3. Name few packages of Bluetooth?

Ans:

Wireless manipulate of and communication between a cellular smartphone and a arms loose headset or automobile kit. This is the maximum popular use.

Wireless networking between PCs in a constrained area and wherein little bandwidth is required.

Wireless communications with PC enter devices which includes mouses and keyboards and output devices such as printers.

Transfer of files between gadgets thru OBEX.

Transfer of contact info, calendar appointments, and reminders among gadgets thru OBEX.

Replacement of traditional stressed serial communications in take a look at device, GPS receivers and clinical device.

For far off controls wherein infrared become historically used.

Sending small advertisements from Bluetooth enabled advertising and marketing hoardings to different, discoverable, Bluetooth gadgets.

Wireless control of a video games console, Nintendo’s Wii and Sony’s PlayStation 3 will both use Bluetooth generation for his or her wireless controllers.

Sending instructions and software to the upcoming LEGO Mindstorms NXT in preference to infra purple.

Q4. Why can Bluetooth device combine easily in TCP/IP community? 

Ans: Because Bluetooth uses wi-fi LAN standards IEEE for statistics transmission.

Q5. Is it possible to attach a couple of Bluetooth hubs? 

Ans: No, only one hub can be used at a time with a pc. USB or Serial gadgets can be introduced.

Q6. What are Different Classes in Bluetooth?

Ans: Bluetooth is a radio fashionable and communications protocol on the whole designed for low electricity intake, with a short range (strength magnificence based: 1 meter, 10 meters, one hundred meters) based round low-cost transceiver microchip in each tool.

Bluetooth lets those devices speak with each other while they're in range. The gadgets use a radio communications machine, so they do now not should be in line of sight of every other, and might also be in different rooms, as long as the obtained strength is excessive sufficient.

Q7. What is FCC and how does it relate to Bluetooth? 

Ans: FCC is Federal Communication Commission, which problems licenses to the stations for specific frequencies. It additionally makes a decision who is capable of use which frequency for what reason. Since Bluetooth is the usage of unlicensed spectrum, FCC has no direct involvement with Bluetooth

Q8. What are a number of the makes use of of Bluetooth?

Ans: Depending at the Bluetooth profiles included on the device, Bluetooth generation has the functionality to wirelessly synchronize and transfer facts amongst gadgets. The Bluetooth audio abilities may be used for headset and hands loose packages. The specific functionality furnished through a Bluetooth enabled device relies upon on the Bluetooth profiles included.

Q9. How does Bluetooth in shape in with WiFi?

Ans: The 802.11b (WiFi) wellknown is commonly used for wi-fi networking. Bluetooth isn't a competitor with 802.11b, but as an alternative a supplement to it. While 802.11b is generally a replacement for wired local region networking, Bluetooth is extra usually used as a replacement for cables between man or woman gadgets. Bluetooth is designed to link devices inside a very quick variety (up to 33 toes ). Bluetooth is a part of the 802.15 fashionable.

Q10. Under what frequency variety does Bluetooth work? 

Ans: 2.45 GHz is the frequency variety.

Q11. Do Bluetooth gadgets need line of sight to connect to one another? List the variations among Bluetooth and Wi-Fi IEEE 802.11 in networking.

Ans: Bluetooth technology is to update cables, while Wi-Fi is utilized for supplying wireless, excessive-pace get admission to to the Internet or a nearby location network.

Bluetooth is particular for fast transmission speeds of 800 kbps, where as Wi-Fi’s transmission speed is 11 mbps.

Bluetooth is a short-range community specification with 30 feet, wherein as Wi-Fi is aimed at 300 feet.

Bluetooth allows connecting to printers, notebooks, mobile smartphone and cell books, with out cables. Wi-Fi allows sharing high-speed internet connections with out cables.

Q12. What is Bluetooth SIG?

Ans: Bluetooth Special Interest Group (SIG) :Bluetooth wi-fi era is revolutionizing private connectivity by using providing freedom from wired connections. It is a specification for a small-shape thing, low-cost radio answer supplying hyperlinks among cellular computer systems, cellular phones, other portable handheld gadgets and vehicles, in addition to connectivity to the Internet. The Bluetooth SIG, made out of leaders inside the telecommunications, computing, car and customer electronics industries, is driving improvement of the generation and bringing it to market. The Bluetooth SIG includes Promoter member agencies Agere, Ericsson, IBM, Intel, Microsoft, Motorola, Nokia and Toshiba, and hundreds of Associate and Adopter member businesses. The Bluetooth SIG, Inc. Headquarters are placed in Overland Park, Kansas, U.S.A.

Q13. How many gadgets can talk simultaneously?

Ans: A Bluetooth tool gambling the position of the “grasp” can communicate with up to 7 devices gambling the function of the “slave”. This community of “organization of up to 8 devices” (1 grasp + 7 slaves) is known as a piconet. A piconet is an ad-hoc pc community of devices using Bluetooth technology protocols to permit one master device to interconnect with as much as seven active slave devices (because a three-bit MAC deal with is used). Up to 255 in addition slave devices may be inactive, or parked, which the grasp device can convey into lively status at any time.

Q14. What is Pairing?

Ans: Pairs of gadgets might also establish a relied on courting by way of gaining knowledge of (by means of person input) a shared mystery known as a “passkey”. A device that desires to talk only with a relied on device can cryptographically authenticate the identification of the alternative device. Trusted devices might also encrypt the records that they alternate over the air in order that no one can concentrate in. The encryption can however be became off and passkeys are stored at the tool’s report machine and now not the Bluetooth chip itself. Since the Bluetooth deal with is permanent a pairing could be preserved even supposing the Bluetooth call is modified. Pairs may be deleted at any time through either tool. Devices will normally require pairing or will prompt the proprietor before it permits a far flung tool to apply any or maximum of its offerings. Some gadgets which include Sony Ericsson phones will usually be given OBEX commercial enterprise playing cards and notes without any pairing or prompts. Certain printers and get admission to factors will allow any device to apply its services by using default just like unsecured Wi-Fi networks.

HubSpot Video
 

Q15. How at ease a Bluetooth device is?

Ans: Bluetooth uses the SAFER+ set of rules for authentication and key generation. The E0 circulation cipher is used for encrypting packets. This makes eavesdropping on Bluetooth-enabled gadgets more hard.

Q16. What form of encryption can be used for Bluetooth security?

Ans: The Bluetooth specification 1.0 describes the link encryption set of rules as a move cipher the use of 4 LFSR (linear remarks shift registers). The sum of the width of the LFSRs is 128, and the spec says “the powerful key duration is selectable among eight and 128 bits”. This association permits Bluetooth to be used in international locations with policies proscribing encryption electricity, and “facilitate a destiny upgrade path for the safety with out the need for a pricey remodel of the algorithms and encryption hardware” according to the Bluetooth specification. Key technology and authentication seems to be using the eight-round SAFER+ encryption set of rules. The information available suggests that Bluetooth security can be good enough for maximum purposes; but customers with better protection necessities will want to rent more potent algorithms to make certain the safety in their information.

Q17. What is the variety of Bluetooth transmitter/receivers?

Ans: Bluetooth is designed for terribly low power use, and the transmission range will simplest be 10m, approximately 30ft. High-powered Bluetooth gadgets will allow degrees up to 100m (300ft). Considering the layout philosophy in the back of Bluetooth, even the 10m variety is good enough for the functions Bluetooth is intended for. Later variations of the Bluetooth spec might also allow longer levels.

Q18. What is the facts throughput pace of a Bluetooth connection?

Ans: Bluetooth transfers information at a charge of 721 Kbps, which is from 3 to 8 times the average velocity of parallel and serial ports, respectively. This bandwidth is able to transmitting voice, data, video and nevertheless pictures

Q19. What is a Bluetooth dongle? 

Ans: A tool that hangs outdoor of a computer, or telephone to provide Bluetooth connection.

Q20. What are the alternative (competing or no longer) wi-fi technology? 

Ans: Wi-Fi, IrDa, EDGE, UWB (Ultra Wide Band)

Q21. Which Bluetooth model makes use of adaptive frequency hopping? Why? 

Ans: In Version 1.2 Adaptive frequency hopping technique is used, which improves resistance to radio interference, and presents better transmission pace.

Q22. How many SCO links are there in a piconet?

Ans: In a piconet, there can be up to a few SCO hyperlinks of 64,000 bits according to second every.

Q23. What is the whole number of masters and slaves in a piconet?

Ans: 1 Master and 7 Slaves.

Q24. Which method is used for Data switch?

Ans: Asynchronous Connectionless (ACL) is Data transfer method in Bluetooth.

Q25. What is RJ-45?

Ans: RJ-45 stands for Registered Jack – forty five. It is an 8-twine connector for connecting pc structures directly to a LAN, mainly Ethernets. These connections are similar in appearance to the ever-present RJ-eleven, that are utilized in connecting cellphone gadget, with little greater width.

Q26. Which technology is used to keep away from interference in Bluetooth?

Ans: Blue tooth uses frequency hopping generation. In this era, 79 hop frequencies are transmitted and acquired from 2402 to 2480 mhz. Hopping in a pseudo random series at a charge of 1600 times in a 2nd. Guassian frequency shift keying modulation is utilized with a maximum data transfer price of 721 kbps. Bluetooth protocol stack is advanced and TCP/IP imported layers are used on this era.

Interference is being averted through making use of the frequency-hop(FH) unfold spectrum era. It is adaptable for low-energy, low-fee radio implementations and extensively utilized in sure wi-fi LAN merchandise.

The foremost benefit with this generation transmission is the excessive fee of 1600 hops / ps. Another gain is, short packet duration is likewise utilized by Bluetooth.