IT 300 CH 6

what are the three methods for secure communication - bluethooth

1) authentication 2) data encryption 3) generation of session key

Physical Topology

Aligns with the specific LAN standard, the types of network devices available and logical topology of network

what is the mechanism used for 802.11?

CSMA/CA listen to the channel frequency for any traffic prior to sending frames

what is DTE and describe it

Data terminal equipment - end devices liked terminals, computers and servers

Logical Topology

Describes how connected computers are arranged to communicate with one another over the physical topology

IEEE 802.3 what is it?

Ethernet LAN that describes botht the physical layer and data link layer - 1983

An IEEE 802.11 wireless LAN (WLAN) does not share a common medium and therefore data collisions are not possible. This is the reason why CSMA/CD is not used on WLANs.

FALSE

For a local area network (LAN), the physical topology must always be the same as the logical topology.

FALSE

Regarding WLAN security, WEP (wired equivalent privacy) is much better than the older WPA2 (WiFi protected access).

FALSE

The IEEE 802.3 Ethernet standard only describes the Data Link Layer of the OSI Reference Model. Therefore, any physical medium can be used.

FALSE

______________ is the standard for wireless LAN (WLAN ) and uses what?

IEEE 802.11 uses de-centralized distributed coordination function (DCF) tp enable access on shared air space

Ethernet is divided into ________ and ____________ sublayers

LLC (logical link control)-- MAC(medium access control)-- layer 2

define LAN and what it does

Local Area Network comprised of multiple PC's and servers interconnected to one another through guided and unguided medium

What is the MAC layer and what does it do

Medium access control lowermost layer within the OSI model involving either a centralized or distributed control mode

what is P2P

P2P - all computers connect directly to one another in order to share information

A shared IEEE 802.3 Ethernet LAN requires the CSMA/CD protocol to help avoid data collisions; however, data collision can still occur.

TRUE

Data collisions will not occur when implementing full-duplex (FDX) switched Ethernet.

TRUE

For 802.11 WLANs, the four frame exchange protocol is implemented to help avoid the hidden node problem.

TRUE

For 802.3 LANs, a hybrid canceller transceiver device is used which enables full-duplex data communications

TRUE

For WLAN applications, 2.4 GHZ ISM channels overlap, while channels in the 5G ISM range are adjacent to one another.

TRUE

The Bluetooth access code is defined by the master node within a piconet, and is unique to that piconet

TRUE

The use of 4B5B encoding enables 100BaseTx Ethernet LANs to use a simpler form of line coding (i.e., NRZ-Inverted). However, by doing this, a 20% overhead penalty resulting in a reduced data throughput is incurred.

TRUE

ZigBee is an 802.15.4 specification intended to be a less expensive and simpler than Bluetooth WPAN.

TRUE

define WAN and what it does

Wide Area Network Spans greater distances and are commonly used to interconnect LANS together from different geographical locations

define WLAN and what it does

Wireless LAN Allows PC's to wirelessly connect to the network through AP (access points)

define WPAN and what it does

Wireless Personal Area Network Cables connecting peripheral devices (mouse/keyboard)

What does 100BaseT mean? Answers: a. 100 Mbps, baseband, twisted pair b. 100 bps, baseband, twisted pair c. 100 meters, baseband, transmit d. 100 kilometers, baseband, transmit

a. 100 Mbps, baseband, twisted pair

shared Ethernet

all connected devices receive all transmitted data frames regardless of whether they are the intended receipient or not -lot of collision

what is Zig bee

another form of Bluetooth good battery ideal protocol that suppor tht internet of things supporting residential and commercial purposes LOW DATA RATES

Select the correct statement(s) regarding peer-to-peer (P2P) networks. Answers: a. computers on P2P networks have a centralized location for all shared data b. there is a possibility that duplicate data files will exist on a P2P network c. P2P networks always use centralized authentication and access methods d. all are correct statements

b. there is a possibility that duplicate data files will exist on a P2P network

Hub

broadcast device designed with several ports used to connect each computer on the LAN

what is CSMA and what does it do

carrier sense multiple access tell you that all nodes on the LAN have access to the shared medium, and that each node must continuously listen and be aware of any data traffic or collision on the medium

OS

clients that run on a computer

10Base -TX Ethernet LAN

configured in a physical star topology with all computer connected to hub

802.15.1= bluethooth what capabilities does it have

core adopted optional

What is correct regarding 100Base-TX? Answers: a. By using 4B5B coding, only 80% of the logical data sent represents real information (i.e., 20% of the bits are considered overhead) b. Can operate in full or half-duplex modes over two pair or single pair wire respectively. c. Operates over Cat5e UTP which enables a signaling rate of 125 MBaud d. All are correct

d. All are correct

In order to achieve 1Gbps (1GbE) over Cat5e cabling, what needs to be done? Answers: a. Use all four wire pairs in full-duplex b. Apply PAM-5 modulation to achieve N=2 (bits per symbol) c. Use hybrids that enable full-duplex transmission over a single wire pair d. All of the above

d. All of the above

Increasing data capacity (i.e., throughput) on an 802.3 LAN using UTP can be done by: Answers: a. Increasing wire gauge (e.g., go from Cat5e to Cat6 or 7) b. Adopting a line coding technique with a higher "M" c. Enabling both transmit and receive on a single wire pair using magnetic hybrid technology d. All of the above

d. All of the above

What are ways to increase data capacity on an 802.11 WLAN? Answers: a. increase frequency bandwidth b. increase operating frequency c. use M'ary modulation d. All of the above

d. All of the above

Select the correct statement regarding 802.15 Bluetooth Answers: a. FHSS operates at 1600 hops per second over 79 one MHz channels b. Bluetooth is a centralized access model where the master nodes acts as the centralized controller c. FHSS is a spread spectrum technology used in 802.15 WPANs d. All of the above are correct

d. All of the above are correct

Select the correct statement(s) regarding 802.11 WLANs. Answers: a. Operates over unlicensed ISM frequencies b. Implements spread spectrum or OFDM techniques for better noise resistance and spectral efficiency c. Uses CSMA/CA since collisions are always possible d. All of the above are correct

d. All of the above are correct

Select the correct statement(s) regarding the 802.3 MAC layer. Answers: a. The MAC layer resides in the data link layer 2, under the LLC layer b. The MAC layer is where the 48 bit data link address resides c. MAC is responsible for contention-based access (i.e., CSMA/CD or CSMA/CA) d. All of the above are correct

d. All of the above are correct

Select the correct statement(s) regarding 802.15 Bluetooth piconets and scatternets. Answers: a. A device in one piconet cannot participate as a device in another piconet at the same time b. A scatternet is comprised of 8 or more devices c. A bridge device acts to interface the Bluetooth device to a LAN d. Up to eight devices can comprise a piconet

d. Up to eight devices can comprise a piconet

Select the correct statement(s) regarding 802.11 specifications. Answers: a. 802.11 operates on ISM frequencies. Using 5 GHz vice 2.4 GHz frequencies enable higher bit rate capacity. b. MIMO is used in later specifications to help increase bit rate throughput c. M'ary modulation techniques are used to increase bit rate capacity d. all are correct statements

d. all are correct statements

Select the correct statement(s) regarding decentralized (distributed) access control on a LAN. Answers: a. no centralized access process exists, and therefore each connected station has the responsibility for controlling its access b. data collisions are possible, therefore mechanisms such as CDMA/CD are required c. when a data collision occurs, the nearest station detecting the collision transmits a jamming signal d. all of the above are correct

d. all of the above are correct

what is DCE and describe it

data communication equipment describes the network equipment such as modems

what is LLC sub layer

data link and network layer responsible for interface between MAC and statndard such as IP, IPX, ARP prepares packets for framing MAC layer connection or connectionless

what is L2CAP

data link control protocol enables 3 types of logical connections: connectionless- simplex channel from master to slave nodes conecction oriented - FDX services are established between master and slave nodes signaling - singalling messages between L2CAP device

what is MAC sub-layer

data link layer- works closely with physical layer responsible for generation of preamable and creation of Ethernet data frame which encapsulates data delivered from the detection field for frame 48 bit

what is 10Base 2/ 10Base5

describes certain physical characteristics of coaxial cable

NOS (network operating system)

designed specifically to operate in the clien server envionrment

switched Ethernet

devices are connected to the switch through dedicated full duplex links-- meaning no toehr device shares physical link (different paths)

describe IEEE 802.3 TODAY

emerged as the LAN standard of choice upgraded 10GBase-T- over twisted pair guided medium

what is baseband layer

formation of piconets and scatternets.

what are the 2 handshaking protocols used with CA?

frame exchange protocol RTS (request to send)

DTEandDCEareaconventionsthathelp

identify physical layer communication characterisitics between device in a network

difference between jamming and wait

jamming - informs other nodes they must cease all transmission wait - period before being allowed to transmit data

what is LMP

link manager protocol link set up and management between master ans slave nodes within the piconet includes qos.

what is distributed access control approach?

no centralized process. each node on the LAN is responsible for determining if it can access the shared medium. data collisions can occur

What is Token Ring (IEEE 802.5)

passing of tokens from one computer to the next in circular round robin fashion

networks can have ______ and _______ configurations that differ

physical logical

LAN is configured as a _________ star but operates as a ___________ bus

physical star logical bus

what is client server

provide highly capable network computers that provide centralized services and data storage easily assed by user computers (clients)

what is radio layer

responsible for establishing phywidql link within piconet. identifies transmission power, frequency , modulation and hopping sequence

centralized control leads to deterministic access which means?

the node in the possession of the token has sole access to the medium without fear of interferences from other nodes

Centralized access control approaches can involve...

the passing of a token or the use of polling by a master controller that grants transmits access to individual nodes on the network

WHat is thicknet vs thinet/cheapernet

thickent - thickness of coaxial cable thinnet - thinner coaxial cable that reduced the maximum LAN cable length

cross over cable

used to connect devices (DTE interface to another DTE interface) or DCE interface connections

what is frame exchange protocol?

when the transmistting node sends a data frame to the intended receiver and the receiver sends back and acknowledgement (ACK)

what is the four frame exchange?

where transmitter sends a RTS (request to send) frame to the receiver the receiever respondes with a CTS (clear to send) and upon receipt, the transmitter begins sending data.

IEEE 802.15.4 is considered what

zig bee