Q&A Hero

Q: For the lower data rates the ________ MAC protocol is used.

Q: A ________ is a collection of interconnected access points with a software protocol structure that enables communication.A) networkB) I/O channelC) carrier access stationD) Fibre channel

Q: The principle driving requirement for ________ is the increase in Internet and intranet traffic. A) 10 Gigabit Ethernet B) 100BASE-LX C) 10BASE-T D) 10BASE-5

Q: Which of the following makes use of two optical fiber cables, one for transmission and one for reception, and utilizes a technique known as intensity modulation. A) 10BASE-T B) 100BASE-FX C) 100BASE-T4 D) 10BASE-F

Q: The IEEE 802.3 standard allows a maximum of ________ repeaters between any two stations with the 10BASE5 alternative. A) two B) four C) three D) five

Q: The sequence 10101011 is the ________ and indicates the actual start of the frame and enables the receiver to locate the first bit of the rest of the frame. A) start frame delimiter B) frame check sequence C) preamble D) LLC data

Q: The CSMA/CD algorithm used in the IEEE 802.3 standard is ________. A) ALOHA B) nonpersistent C) 1-persistent D) p-persistent

Q: One of the rules for CSMA/CD states, "after transmitting the jamming signal, wait a random amount of time, then attempt to transmit again". This random amount of time is referred to as the ________. A) precursor B) backlog C) carrier time D) backoff

Q: A set of options that use two physical links between nodes, one for transmission and one for reception, is ________. A) 100BASE-X B) 100BASE-T C) 100BASE-FX D) 100BASE-TX

Q: With ________, a station wishing to transmit first listens to the medium to determine if another transmission is in progress. If the medium is in use, the station must wait. If the medium is idle, the station may transmit. A) ALOHA B) transmission backlog delay C) Ethernet D) CSMA

Q: A VLAN ________. A) must not indicate VLAN membership B) is also referred to as a TCI C) can span multiple interconnected switches D) is limited to one switch

Q: A problem with ________ is that capacity is wasted because the medium will generally remain idle following the end of a transmission, even if there are one or more stations waiting to transmit. A) p-persistent CSMA B) nonpersistent CSMA C) 1-persistent CSMA D) slotted ALOHA

Q: Ethernet now encompasses data rates of ________. A) 10 Mbps, 100 Mbps, 1000 Mbps, and 10 Gbps B) 10 Mbps, 100 Mpbs, 1 Gbps, and 10 Gbps C) 1 Gpbs, 10 Gbps, 100 Gbps, and 1000 Gbps D) 100 Mpbs, 1 Gbps, 10 Gbps, and 100 Gbps

Q: Two frames interfering with each other at the receiver so that neither gets through is known as ________. A) a collision B) a backlog C) a backoff D) scrambling

Q: A technique known as slotted ________ organizes time on the channel into uniform slots whose size equals the frame transmission time. Transmission is permitted to begin only at a slot boundary. A) ALOHA B) CSMA C) boundary relay D) Ethernet

Q: Store-and-forward switch and cut-through switch are two types of ________ switches that are available as commercial products.

Q: The ________ approach is a mechanism in which bridges automatically develop a routing table and update that table in response to changing topology.

Q: The ________ is designed for use between local area networks that use identical protocols for the physical and link layers and, because the devices all use the same protocols, the amount of processing here is minimal.

Q: The function of a ________ protocol is to control access to the transmission medium in order to provide for an orderly and efficient use of that capacity.

Q: The basic logical link control protocol is modeled after ________ and has similar functions and formats.

Q: There are four alternative media that can be used for a bus LAN: baseband coaxial cable, broadband coaxial cable, optical fiber, and ________.

Q: In the ________ topology each station is directly connected to a common central node, typically via two point-to-point links, one for transmission and one for reception.

Q: The network consists of a set of ________ joined by point-to-point links in a closed loop in the ring topology. These are capable of receiving data on one link and transmitting them, bit by bit, on the other link as fast as they are received.

Q: The tree layout begins at a point known as the ________.

Q: The ________ topology is a special case of the tree topology, with only one trunk and no branches.

Q: The key elements of a local area network are medium access control, transmission medium, wiring layout, and ________.

Q: A ________ is a broadcast domain consisting of a group of end stations, perhaps on multiple physical LAN segments, that are not constrained by their physical location and can communicate as if they were on a common LAN.

Q: The total collection of devices that receive broadcast frames from each other is referred to as a ________.

Q: A ________ consists of a shared transmission medium and a set of hardware and software for interfacing devices to the medium and regulating the orderly access to the medium.

Q: The topologies that have been used for LANs are ring, bus, tree, and ________.

Q: Which of the following is NOT a characteristic of a bridge?A) The bridge makes no modification to the content or format of the frames it receives.B) The bridge must contain addressing and routing intelligence.C) There may not be more than two LANs interconnected by a number of bridges.D) The bridge should contain enough buffer space to meet peak demands.

Q: The term ________ means that all users share a common MAC broadcast address. A) broad B) SAN C) flat D) storm

Q: The key parameters in any medium access control technique are ________. A) when and where B) where and how C) how and when D) why and how

Q: The ________ specifies the mechanisms for addressing stations across the medium and for controlling the exchange of data between two users. A) MAC B) LLC C) LAN D) PDU

Q: The central element of the star topology is a ________. A) router B) hub C) subnetwork D) switch

Q: In the ________ topology the transmission medium is a branching cable with no closed loops. A) bus B) linear C) ring D) tree

Q: In the ________ all stations attach directly to a linear transmission medium. A transmission from any station propagates the length of the medium in both directions and can be received by all other stations. A) backend network B) bus topology C) tree topology D) medium access link

Q: The term ________ refers to the way in which the end points, or stations, attached to the network are interconnected. A) control link B) topology C) medium D) medium access link

Q: The principle disadvantage of VLAN "membership by port group" is that ________.A) it requires switches to examine portions of the MAC frame above the MAC layer causing a performance impactB) VLAN membership must be assigned initiallyC) it is relatively easy to configureD) the network manager must reconfigure VLAN membership when an end system moves from one port to another

Q: The ________ topologies are passive sections of cable to which stations are attached. A) tree and ring B) tree and bus C) star and tree D) bus and ring

Q: A ________ is a logical subgroup within a LAN that is created by software rather than physically moving and separating devices. A) SAN B) VAN C) SLAN D) VLAN

Q: A ________ LAN includes a central node to which stations are attached. A) bus B) star C) tree D) ring

Q: A ________ is where the destination MAC address indicates that all devices on the LAN should receive a copy of the frame. A) unicast address B) multicast address C) simulcast address D) broadcast address

Q: The simplest approach to interconnecting multiple LANs within an organization is to use a ________. A) hub B) bridge C) switch D) gateway

Q: A ________ local area network consists of a closed loop of repeaters that allow data to circulate around the ring. A) FDDI B) ring C) star D) tree

Q: The bridge provides an extension to the LAN once modifications to the communications software in the stations attached to the LAN are made.

Q: The choice for transmission medium and topology is critical in LAN design.

Q: Each station attaches to the network at a repeater in the star topology and can transmit data onto the network through the repeater.

Q: A hub can be configured to recognize a malfunctioning station that is jamming the network and to cut that station out of the network.

Q: The key elements of the local area network determine the cost and capacity of the LAN, the type of data that may be transmitted, the speed and efficiency of communications, and the kinds of applications that can be supported.

Q: One simple approach to improving efficiency is to physically partition the LAN into separate broadcast domains.

Q: A router is not required to link from one VLAN to another.

Q: A transmission of a frame by any one station in a bus or tree topology can be heard by other stations.

Q: A set of standards has not yet been defined for LANs that specify a range of data rates due to the variety of topologies and transmission media.

Q: Transmission is generally in the form of frames when using a ring topology.

Q: Switches and hubs form the basic building blocks of most local area networks.

Q: In a star topology a repeater may also function as a device attachment point.

Q: Unicast addressing is where the destination address in the MAC frame designates a unique destination.

Q: WANs have much greater capacity than LANs to carry what is generally a greater internal communications load.

Q: Local Area Networks are usually owned by the organization that is using the network to interconnect equipment.

Q: In a multipath environment, if the multiple versions of a signal arrive more than one chip interval apart from each other, the receiver can recover the signal by correlating the chip sequence with the dominant incoming signal. The remaining signals are treated as noise. However, even better performance can be achieved if the receiver attempts to recover the signals from multiple paths and then combine them with suitable delays. This principle is used in the ________ receiver.

Q: The key technology for 4G systems is ________.

Q: The term ________ refers to the provision of multiple fixed data rate logical channels to a given user, in which different data rates are provided on different logical channels. The traffic on each logical channel can be switched independently through the wireless and fixed networks to different destinations.

Q: Second generation systems provide multiple channels per cell, but each channel is dynamically shared by a number of users using time division multiple access or ________.

Q: Since the early 1980s the most common first-generation system in North America has been the ________ developed by AT&T.

Q: The efforts to compensate for the errors and distortions introduced by multipath fading fall into three general categories: forward error correction, diversity techniques, and ________.

Q: As the mobile user covers distances well in excess of a wavelength, the urban environment changes as the user passes buildings of different heights, vacant lots, and intersections. Over these longer distances, there is a change in the average received power level about which the rapid fluctuations occur. This is referred to as ________.

Q: If there is no clear line-of-sight to the transmitter, such as in an urban area at street level, then diffraction and ________ are the primary means of signal reception.

Q: ________ occurs at the edge of an impenetrable body that is large compared to the wavelength of the radio wave. When a radio wave encounters such an edge, waves propagate in different directions with the edge as the source. Thus, signals can be received even when there is no unobstructed line-of-sight from the transmitter.

Q: The ________ connects calls between mobile units, makes connections between a fixed subscriber to the public network and a mobile subscriber to the cellular network, assigns the voice channel to each call, performs handoffs, and monitors the call for billing information.

Q: The number of cells in a repetitious pattern, (each cell in the pattern uses a unique band of frequencies), is termed the ________.

Q: Each cell in a cellular network is allocated a band of frequencies and is served by a ________ consisting of transmitter, receiver and control unit.

Q: The objective of the ________ of wireless communication is to provide fairly high speed wireless communications to support multimedia, data, and video, in addition to voice.

Q: First generation cellular networks made use of ________ multiplexing.

Q: The time variation of received signal power caused by changes in the transmission medium is referred to as ________, which is a major technical problem for cellular networks.

Q: A ________ is used to identify the user and register its location. A) page B) handoff C) handshake D) reflection

Q: The dominant technology for third generation systems is ________. A) IMT-TC B) UMTS C) CDMA D) TDMA

Q: ________ can be applied to transmissions that carry analog information or digital information and is used to combat intersymbol interference. A) Forward error correction B) Diffraction C) Adaptive equalization D) Frequency diversity

Q: Nonselective, or ________, is the type of fading in which all frequency components of the received signal fluctuate in the same proportions simultaneously. A) slow fading B) fast fading C) diverse fading D) flat fading

Q: ________ occurs when an electromagnetic signal encounters a surface that is large relative to the wavelength of the signal. A) Scattering B) Diffraction C) Reflection D) Termination