Network+ Chapter 1

Which of the following layers of the Open Systems Interconnection (OSI) model typically have dedicated physical hardware devices associated with them? (Choose all that apply.) A. Physical B. Data link C. Network D. Transport E. Session F. Presentation G. Application

A, B, C. The physical layer of the OSI model is associated with hubs, cables, and network interface adapters. The data link layer is associated with bridges and switches. The network layer is associated with routers. The transport, session, presentation, and application layers are typically not associated with dedicated hardware devices.

Which of the following protocols operate at the application layer of the Open Systems Interconnection (OSI) model? (Choose all that apply.) A. HTTP B. SNMP C. ICMP D. IGMP E. UDP

A, B. Hypertext Transfer Protocol (HTTP) and Simple Network Management Protocol (SNMP) operate at the application layer. Internet Control Message Protocol (ICMP) and Internet Group Management Protocol (IGMP) both operate at the network layer. User Datagram Protocol (UDP) operates at the transport layer.

Which two of the following constructs provide roughly the same function? (Choose two that apply.) A. SIP trunk B. CSU/DSU C. VoIP gateway D. Smartjack E. VPN concentrator

A, C. A Session Initiation Protocol (SIP) trunk provides a connection between the private and public domains of a unified communications network. A Voice over Internet Protocol (VoIP) gateway provides a connection between an IP network and the Public Switched Telephone Network (PSTN). Both of these provide a conduit between a subscriber's private network and the network furnished by a service provider. A Channel Service Unit/Data Service Unit (CSU/DSU) is a device that provides a router on a private network with access to a leased line. A smartjack provides signal conversion, diagnostic testing, and other capabilities to leased line subscribers. A Virtual Private Network (VPN) concentrator is a type of router that enables multiple client systems to access a network from remote locations.

On an Ethernet network using the star topology, which of the following devices can function as the cabling nexus that forms the figurative center of the star? (Choose all that apply.) A. Hub B. Router C. Switch D. Access Point

A, C. A hub or a switch can function as the cabling nexus at the center of an Ethernet star topology. Each of the devices on the network is connected by a cable to a hub or switch. Routers are used to connect networks to each other; they cannot function as the center of a star topology.

Which of the following network topologies are used by Wireless Local Area Networks (WLANs)? (Choose all that apply.) A. Ad hoc B. Bus C. Infrastructure D. Star

A, C. WLANs can use the ad hoc topology, in which devices communicate directly with each other, or the infrastructure topology, in which the wireless devices connect to an access point. The bus and star topologies are used by wired networks only.

Which of the following coaxial cable types are still in general use? (Choose all that apply.) A. RG- 6 B. RG- 8 C. RG- 58 D. RG- 59

A, D. RG- 6 and RG- 59 are 75 ohm cables that are still used for cable television and similar connections. RG- 8 and RG- 58 are 50 ohm cables that were formerly used for Thick Ethernet and Thin Ethernet, respectively, but are no longer in general use.

Which of the following Ethernet physical layer options does not use the star topology? A. 10Base2 B. 10Base- T C. 100Base- TX D. 1000Base- T

A. 10Base2 is the physical layer specification for Thin Ethernet, which uses coaxial cable in a bus topology. 10Base- T, 100Base-T X, and 1000Base- T all use twisted pair cable in a star topology.

Which of the following telecommunications components is all but obsolete and is found only in old, analog telephone installations?A.66 block B.110 block C. Patch panel D. Smartjack

A. A 66 block is a type of punchdown block for telephone systems that was first introduced in 1962. By the year 2000, nearly all commercial telephone installations had begun using 110 blocks instead; 110 blocks are still in use, as are smartjacks and patch panels.

Which of the following topologies requires the installation of terminating resistors at two locations? A. Bus B. Star C. Ring D. Mesh

A. A bus topology requires terminating resistors at each end of the bus, to remove signals as they reach the end of the cable and prevent them from reflecting back in the other direction and interfering with newly transmitted signals. Star, ring, and mesh topologies do not require terminating resistors.

An electrician installing a new light fixture accidentally severs one of the LAN cables running through the dropped ceiling space. With which topology would the severed cable cause the greatest amount of disturbance to the network? A. Bus B. Star C. Logical ring D. Mesh

A. A cable break in a bus topology would split the network into two halves, preventing the nodes on one side of the break from communicating with those on the other. In addition, both halves of the network would be left with one unterminated end, which would prevent the computers on each side of the break from communicating effectively. A cable break in a star or logical ring topology would only interrupt the connection of a single computer to the network. The mesh topology is not often used for LANs, but redundant network connections are a characteristic of mesh networks, which means that a single cable break would have no effect on the network.

Which of the following devices operates only at the physical layer of the Open Systems Interconnection (OSI) model? A. Hub B. Bridge C. Switch D. Router

A. A hub functions only at the physical layer by forwarding all incoming signals out through all of its ports. Bridges and switches operate at the data link layer by selectively propagating incoming data. Routers operate at the network layer by connecting local area networks (LANs) and propagating only the traffic intended for another network, based on IP addresses.

Alice has constructed a five- node failover cluster in which all five servers are connected to a hard disk array using a dedicated Fibre Channel network. Which of the following terms describes this network arrangement? A. SAN B. PAN C. WAN D. MAN

A. A storage area network (SAN) is a network that is dedicated to carrying traffic between servers and storage devices. A Personal Area Network (PAN) provides communication among devices associated with a single person, such as smartphones. A Wide Area Network (WAN) is a network that connects devices or networks at different geographic locations. A Metropolitan Area Network (MAN) is a type of WAN that connects devices within a limited geographic area.

An Ethernet network interface adapter provides functions that span which two layers of the Open Systems Interconnection (OSI) model? A. Physical and data link B. Data link and network C. Network and transport D. Transport and application

A. An Ethernet network interface adapter functions at the data link layer by encapsulating network layer data for transmission over the network. It provides physical layer functions by providing the connection to the network medium and generating the appropriate signals for transmission. Network interface adapters do not operate at the network, transport, or application layer.

In which of the following ways does a vSwitch (virtual switch) differ from a physical switch? A. Virtual switches have an unlimited number of ports, whereas physical switches have a specific number. B. Physical switches typically support the creation of VLANs, whereas virtual switches do not. C. Virtual switches cannot forward traffic to the host server running them, whereas physical switches can forward traffic to all connected computers. D. Physical switches always include layer 3 functionality, whereas virtual switches do not.

A. It is true that virtual switches can have unlimited ports, whereas physical switches are limited to the number of physical ports in the device. Both virtual and physical switches can support Virtual Local Area Networks (VLANs). Virtual switches can forward traffic to the host server. Physical switches do not always include layer 3 (routing) functionality.

Which of the following Wide Area Network (WAN) connection technologies uses analog signaling? A. Public Switched Telephone Network (PSTN) B. Cable television (CATV) C. Digital Subscriber Line (DSL) D. Synchronous Optical Network (SONET)

A. PSTN is an analog, circuit- switched network. CATV, DSL, and SONET are all digital networks.

Which of the following is the European equivalent of the Synchronous Optical Networking (SONET) standard in the United States? A. SDH B. OC- 3 C. E- 3 D. ATM

A. Synchronous Digital Hierarchy (SDH) is the European equivalent of SONET. Optical carrier 3 (OC- 3) is one of the SONET data rates. E- 3 is the European equivalent of the T- 3 connection in the United States. Asynchronous Transfer Mode (ATM) is a cell- switched protocol that is designed to carry voice, data, and video traffic by splitting it into uniform 53- byte cells.

Which of the following cable types is used for Thick Ethernet network segments? A.RG- 8 B.RG- 58 C.RJ- 45 D.RJ- 11

A. The cable type used for Thick Ethernet segments is a coaxial cable called RG- 8. RG- 58 is used exclusively on Thin Ethernet segments. RJ- 45 is a connector type used in twisted pair cabling for data networks. RJ- 11 is a connector type used in twisted pair cabling for telecommunications networks.

Which of the following cabling topologies was used by the first Ethernet networks? A. Bus B. Ring C. Star D. Mesh

A. The first Ethernet networks used a physical layer implementation commonly known as Thick Ethernet or 10Base5. The network used coaxial cable in a bus topology. Later Ethernet standards use twisted pair cable in a star topology. Ethernet has never used a ring or mesh topology.

Which of the following components is responsible for providing a virtualized hardware environment and running virtual machines? A. Hypervisor B. Virtual server C. vSwitch (virtual switch) D. VPN concentrator

A. The hypervisor is the hardware or software component responsible for managing virtual machines and providing the virtualized hardware environment on which they run. Virtual servers and virtual switches are components that are part of the virtual network infrastructure enabled by the hypervisor. A Virtual Private Network (VPN) concentrator is a type of router that enables multiple remote clients to connect to a network; it has nothing to do with virtual networking.

Which of the following best describes the function of the network medium? A. The network medium provides the physical connection between networked computers. B. The network medium provides the protocol used to transmit data between end systems. C. The network medium passes data packets between two routers. D. The network medium processes electrical or light signals and converts them to data.

A. The network medium provides the physical connection between networked computers. This connection can be made through a copper- based, fiber-optic, or wireless medium. The network medium is not a protocol, and it does not pass data packets; it only carries signals. The network medium does not process electrical or light pulses and convert them to data; it carries only the signals generated by transceivers.

Alice is a network administrator designing a new Local Area Network (LAN). She needs to determine the type of cabling and the network topology to implement. Which layers of the Open Systems Interconnection (OSI) model apply to cabling and topology elements? A. Physical and data link layers B. Data link and network layers C. Network and transport layers D. Transport and application layers

A. The physical layer defines the mechanical and electrical characteristics of the cables used to build a network. The data link layer defines specific network (LAN or WAN) topologies and their characteristics. The physical layer standard that Alice will implement is dependent on the data link layer protocol she selects. The network, transport, and application layers are not concerned with cables and topologies.

Which layer of the Open Systems Interconnection (OSI) model is responsible for transmitting signals over the network medium? A. Physical B. Data link C. Network D. Transport E. Session F. Presentation G. Application

A. The physical layer of the OSI model defines the functions specific to the network medium and the transmission and reception of signals. All of the other layers are implemented in software and do not physically send or receive signals.

Which layer of the Open Systems Interconnection (OSI) model defines the medium, network interfaces, connecting hardware, and signaling methods used on a network? A. Physical B. Data link C. Network D. Transport E. Session F. Presentation G. Application

A. The physical layer of the OSI model defines the standards for the physical and mechanical characteristics of a network, such as cabling (copper and fiber), connecting hardware (hubs and switches), and signaling methods (analog and digital). All of the other layers are not involved in the mechanical characteristics of the network.

Which type of network connects Local Area Networks (LANs) in distant locations? A. WAN B. LAN C. MAN D. CAN

A. WANs (Wide Area Networks) connect LANs that are geographically distant. A LAN (Local Area Network), as the name implies, is a group of computers, not other LANs, and it is contained within a small area. MANs (Metropolitan Area Networks) connect LANs in a single metropolitan area; they are not confined to a small area. A MAN is typically larger than a LAN but smaller than a WAN. A Campus Area Network (CAN) typically includes a group of adjacent buildings, such as those of a corporation or university.

On a TCP/IP network, which layers of the Open Systems Interconnection (OSI) model contain protocols that are responsible for encapsulating the data generated by an application, creating the payload for a packet that will be transmitted over a network? (Choose all that apply.) A. Physical B. Data link C. Network D. Transport E. Session F. Presentation G. Application

B, C, D. Before the payload data generated by an application can be transmitted over a TCP/ IP network, the system must encapsulate it by applying protocol headers and footers at three layers of the OSI model. The data link layer applies a header and footer to create an Ethernet frame. The network layer applies a header to create an IP datagram. The transport layer applies a TCP or UDP header to create a segment or datagram. The other model layers are involved in the payload transmission process, but they do not encapsulate the payload.

What are the two main factors that affect DSL (Digital Subscriber Line) transmission rates? A.Signal termination B. Distance to the nearest central office C. Line conditions D. Line reflection

B, C. There are two factors that affect DSL transmission rates. The first is the distance to the nearest central office, and the second is the condition and quality of the line. For DSL to achieve higher data rates, the site must be close to the central office and use good- quality lines for signal transmission. The other options are not factors relating to DSL transmission.

Which of the following are types of circuits offered by frame relay services? (Choose all that apply.) A. SRV B. PVC C. SVC D. UPC

B, C. Frame relay services offer permanent virtual circuits (PVCs) and switched virtual circuits (SVCs). SRV is a resource record type in the Domain Name System (DNS), and an Ultra- Physical Contact (UPC) is a type of fiber- optic cable connector.

Which of the following remote access connection technologies can support the simultaneous transmission of voice and data traffic over the Public Switched Telephone Network (PSTN)? (Choose all that apply.) A. Dial- up modem connection B. Integrated Services Digital Network (ISDN) C. Digital Subscriber Line (DSL) D. Synchronous Optical Network (SONET) E. Cable television (CATV) network

B, C. ISDN and DSL are both remote access technologies that enable users to transmit voice and data simultaneously. To do this, DSL splits the lower analog frequency (voice) range from the higher digital frequency (data) range, whereas ISDN provides multiple data channels (called B channels) that allow for both voice and data transmissions. Broadband cable television networks can often support simultaneous voice and data communications, but they use Voice over Internet Protocol (VoIP) to carry voice traffic over the Internet, not the PSTN. Dial- up connections and SONET do not support the simultaneous transmission of voice and data.

Some switches can perform functions associated with two layers of the Open Systems Interconnection (OSI) model. Which two of the following layers are often associated with network switching? (Choose all that apply.) A. Physical B. Data link C. Network D. Transport E. Session F. Presentation G. Application

B, C. The primary function of a switch is to process packets based on their media access control (MAC) addresses, which makes it a data link layer device. However, many switches can also perform routing functions based on IP addresses, which operate at the network layer.

Which of the following network types are typically wireless? (Choose all that apply.) A. WAN B. PAN C. SAN D. WLAN

B, D. Personal area networks (PANs) connect devices associated with a single person, such as smartphones, and are nearly always wireless. Wireless Local Area Networks (WLANs) are wireless by definition. Wide Area Networks (WANs) typically span long distances and are typically wired, at least in part. Storage area networks (SANs) require high performance levels and are nearly always wired.

Which of the following is the device that provides the interface between a Local Area Network (LAN) and a Wide Area Network (WAN)? A. QSFP B. CSU/DSU C. SIP trunk D. IDS/IPS

B. A Channel Service Unit/Data Service Unit (CSU/DSU) is a device that provides a LAN router on a private network with access to a leased line WAN connection. Quad Small Form- factor Pluggable (QSFP) is a standard for a type of modular transceiver, often used on fiber- optic installations. A Session Initiation Protocol (SIP) trunk provides a connection between the private and public domains of a unified communications network, such as a LAN and the Public Switched Telephone Network (PSTN). An intrusion detection system/intrusion prevention system (IDS/IPS) is a network hardware or software security appliance that detects malicious activity and attempts to block it.

Which type of network is typically confined to a small area, such as a single room, floor, or building? A. WAN B. LAN C. MAN D. CAN

B. A Local Area Network (LAN), as the name implies, is a group of computers contained within a small geographic area. WANs (Wide Area Networks) connect LANs that are geographically distant. MANs (Metropolitan Area Networks) are not confined to a small area; they are typically larger than a LAN but smaller than a WAN. A Campus Area Network (CAN) typically includes a group of adjacent buildings, such as those of a corporation or university.

Which of the following best describes the function of a demarcation point or demarc? A. The vertical cross- connect that links horizontal networks together B. The place where an outside service enters the building C. A switch or hub that connects the computers in a particular work area together, forming a horizontal network D. The place in a telecommunications room where a patch panel is located

B. A demarcation point, or demarc, is the place where an outside telecommunications service meets a customer's private network, which is typically where the service enters the building. The demarc is also the place where the responsibility of the network administrator ends. If a problem occurs outside the demarc, it is up to the service provider to fix it. Inside the demarc, it is the network administrator's problem.

Which of the following is an example of a hybrid topology? A. A workstation with two network interface cards, one of which is connected to a star network and one to a bus network B. Four Ethernet switches connected using a bus topology C. Four workstations, each with a separate network connection to each of the other three D. Four Ethernet switches, each with a separate network connection to each of the other three

B. A hybrid topology is a network that uses two or more of the basic topologies, connected together so that each workstation can communicate with all of the other workstations. Connecting four switches to a bus topology combines four- star networks in such a way that the workstations are all interconnected. Connecting a single workstation to a star and a bus network enables that workstation to access both networks, but it does not enable other workstations to access both topologies. Four workstations, each with a separate connection to the other three, is a mesh network topology, not a hybrid. Four connected switches expands the star topology, but it does not create a hybrid topology.

Dense Wave Division Multiplexing (DWDM) is a signalling technology that has become a popular choice in the construction of which of the following types of provider links? A. Digital Subscriber Line (DSL) B. Metro- optical C. Satellite D. Cable

B. DWDM has become a popular technology in the construction of metro- optical networks because it addresses some of the scalability and cost restrictions of other optical technologies, such as Synchronous Optical Networks (SONETs). DSL, satellite, and cable providers do not typically use DWDM.

Ed has been hired by a private company to connect two remote sites with a Wide Area Network (WAN). Each of these sites has more than 200 users, and they all need to constantly transfer files across the WAN. One of the sites has a customer database that is accessed by both sites at all hours of the day. Access to the database and other information is time sensitive and constant. The company estimates that their aggregate bandwidth needs to be approximately 40 Mbps. Management says that they need to guarantee access to this information and that money is not a factor in the WAN implementation. Which WAN technology should Ed recommend for this scenario? A. A standard modem- to- modem connection B. A T-3 dedicated leased line C. A cable television (CATV) connection D. An ADSL (Asymmetrical Digital Subscriber Line) connection

B. For this scenario, the best of the options given is a dedicated leased line connection. This is because the bandwidth requirements are constant, and the data transfer rates are high. To support the 40 Mbps data rate, Ed should recommend a T- 3 dedicated leased line, running at 44.735 Mbps. Standard modem connections, CATV, and ADSL connections are all too slow.

Which of the following technologies can replace leased lines, such as T- 1s, by multiplexing signals as packets switched through virtual circuits in a cloud? A. E- 1s B. Frame relay C. ATM D. PPP

B. Frame relay is a packet switching service that uses a single leased line to replace multiple leased lines by multiplexing traffic through a cloud. The service can create virtual circuits connecting the subscriber's network to multiple destinations, eliminating the need for a dedicated leased line to each remote site. An E- 1 is the European equivalent to a T- 1 leased line, which does not replace multiple T- 1s. Asynchronous Transfer Mode (ATM) is a cell-s witching WAN technology, and Point- to- Point Protocol (PPP) is a protocol that provides a data link layer connection between two end systems. Neither is a replacement for multiple T- 1s.

Specify the layer of the Open Systems Interconnection (OSI) model at which the Internet Protocol (IP) operates and whether it is connection- oriented or connectionless. A. Network; connection- oriented B. Network; connectionless C. Transport; connection- oriented D. Transport; connectionless

B. IP is a connectionless protocol that operates at the network layer of the OSI model. There are no connection- oriented protocols at this layer. The protocols at the transport layer include Transmission Control Protocol (TCP), which is connection- oriented, and User Datagram Protocol (UDP), which is connectionless.

On an unmanaged network, which of the following virtual networking components have media access control (MAC) addresses assigned to them? A. Virtual switches B. Virtual NICs C. Hypervisors D. Virtual firewalls

B. Just like physical network interface cards (NICs), virtual NICs have 6 byte MAC addresses assigned to them, which enable them to be identified by data link layer protocols. Unlike physical NICs, however, it is typically an easy matter to modify a MAC address on a virtual NIC. Virtual switches, like physical switches, are not addressable devices, so they do not have MAC addresses on an unmanaged network. The hypervisor is the component on a host server that makes virtualization possible, so it does not require a MAC address. Virtual firewalls operate at the application layer, so they do not require data link layer MAC addresses. On a managed network, these devices have a MAC address to communicate with the management console, but addresses are not needed on an unmanaged network.

Multiprotocol Label Switching (MPLS) is sometimes said to operate between two layers of the Open Systems Interconnection (OSI) model. Between which two layers is it usually said to function? A. Physical and data link B. Data link and network C. Network and transport D. Transport and Session

B. MPLS is a data- carrying service that is often said to operate between the data link layer and the network layer. It is therefore sometimes called a layer 2.5 protocol. MPLS can be used to carry IP datagrams as well as Ethernet, Asynchronous Transfer Mode (ATM), and Synchronous Optical Network (SONET) traffic.

Which of the following is a wide area networking mechanism that assigns labels to packets and forwards them based on those labels, rather than addresses? A. Frame relay B. MPLS C. ATM D. PPPoE E. SDWAN

B. Multiprotocol Label Switching (MPLS) is a data transfer mechanism that assigns labels to individual packets, and then routes the packets based on those labels. Frame relay, Asynchronous Transfer Mode (ATM), Point- to- Point Protocol over Ethernet (PPPoE), and a Software- Defined Wide Area Network (SDWAN) do not assign labels to packets.

At which layer of the OSI model do you find the protocol responsible for the delivery of data to its ultimate destination on an internetwork? A. Data link B. Network C. Session D. Application

B. On a TCP/IP network, the Internet Protocol (IP) at the network layer is the protocol responsible for the delivery of data to its final destination. Data link layer protocols are only concerned with communication between devices on a Local Area Network (LAN) or between two points connected by a Wide Area Network (WAN) link. The session and application layers are not involved in the actual delivery of data.

Which of the following cable types is used for Thin Ethernet network segments? A.RG- 8 B.RG- 58 C.RJ- 45 D.RJ- 11

B. RG- 58 coaxial cable is used exclusively for Thin Ethernet segments. RG- 8 cable is used for Thick Ethernet segments. RJ- 45 is a connector type used in twisted pair cabling for data networks. RJ-1 1 is a connector type used in twisted pair cabling for telecommunications networks.

At which of the Open Systems Interconnection (OSI) model layers do switches and bridges perform their basic functions? A. Physical B. Data link C. Network D. Transport

B. Switches and bridges are involved in Local Area Network (LAN) communications only and therefore primarily at the data link layer. They are not primarily associated with the physical, network, or transport layers, although some switches include network layer routing capabilities.

Which of the following is not one of the primary components of the Network Function Virtualization (NFV) framework? A. VNF B. NFV ISG C. NFVI D. NFV- MANO

B. The NFV specification, published by the European Telecommunications Standards Institute (ETSI), calls for three main components: virtualized network functions (VNFs), which are software- based implementations of standard network services, such as firewalls and load balancers; a Network Functions Virtualization Infrastructure (NFVI), which is the hardware/ software environment that hosts the VNFs; and a Network Functions Virtualization- Management And Orchestration (NFV- MANO) framework, which includes the elements required to deploy and administer the NFVI and the VNFs. The Network Functions Virtualization Industry Specification Group (NFV ISG) is the group within ETSI that develops the NFV specifications; it is not one of the three components.

Which of the following is the U.S. standard for synchronous data transmissions that defines data rates designated by optical carrier levels, such as OC- 3, OC- 12, OC- 48, and OC- 192? A. SDH B. SONET C. ISDN D. DSL

B. The Synchronous Optical Networking (SONET) standard defines a base data transfer rate of 51.84 Mbps, which is multiplied at the various optical carrier levels. An OC- 3 connection therefore runs at 155.52 Mbps, an OC- 12 at 622.08 Mbps and so forth. The Synchronous Digital Hierarchy (SDH) is the European equivalent of SONET. Integrated Services Digital Network (ISDN) is a service that combines voice and data services using the Public Switched Telephone Network (PSTN), and Digital Subscriber Line (DSL) is a remote access technology that enables users to transmit voice and data simultaneously.

At which layer of the Open Systems Interconnection (OSI) model is there a protocol that adds both a header and footer to the information that is passed down from an upper layer, thus creating a frame? A. Physical B. Data link C. Network D. Transport E. Session F. Presentation G. Application

B. The only layer with a protocol (such as Ethernet) that adds both a header and a footer is the data link layer. The process of adding the headers and footers is known as data encapsulation. All other protocol layers that encapsulate data add just a header.

Which layer of the Open Systems Interconnection (OSI) model would be responsible for converting a text file encoded using EBCDIC on the sending system into ASCII code, when required by the receiving system? A. Application B. Presentation C. Session D. Physical

B. The presentation layer of the OSI model is responsible for translating different kinds of syntax, including text-e ncoding systems, such as EBCDIC and ASCII. The application, session, and physical layers do not perform this function.

Which of the following broadband WAN services provides equal amounts of upstream and downstream bandwidth? A. ADSL B. SDSL C. Satellite D. Cable

B. The word symmetric in Symmetric Digital Subscriber Line (SDSL) means that the service provides equal amounts of bandwidth in both directions. The asymmetric in Asymmetric Digital Subscriber Line (ADSL) means that the service provides more downstream bandwidth than upstream. Cable and satellite services are also asymmetric, providing more bandwidth downstream than upstream.

On which of the following virtual networking components can you create VLANs? A. Virtual NIC B. Virtual switch C. Virtual router D. Virtual firewall

B. You can create Virtual Local Area Networks (VLANs) on a virtual switch, just as you can create them on many physical switches. In most cases, virtual components function just like their physical counterparts. Virtual NICs are components of virtual machines and therefore do not provide functions spanning entire networks. Virtual routers function at the network layer and virtual firewalls at the application layer, so neither of these can host VLANs, which operate at the data link layer.

At which of the following layers of the Open Systems Interconnection (OSI) model do the protocols on a typical local area network (LAN) use media access control (MAC) addresses to identify other computers on the network? A. Physical B. Data link C. Network D. Transport

B. The Ethernet (or IEEE 802.3) protocol at the data link layer uses MAC addresses to identify computers on the local network. MAC addresses are coded into the firmware of physical network interface adapters by the manufacturer. The physical layer deals with signals and is not involved in addressing. The IP protocol at the network layer has its own addressing system. The transport layer protocols are not involved in addressing.

Which of the following types of Wide Area Network (WAN) connections commonly use Point- to- Point Protocol over Ethernet (PPPoE)? (Choose all that apply.) A. Leased lines B. SONET C. Cable broadband D. Digital Subscriber Line (DSL)

C, D. Cable broadband and DSL subscribers typically connect to ISP networks that run Ethernet, but Ethernet has no built-i n authentication or encryption mechanisms. PPP has the ability to use external authentication and encryption protocols, so by encapsulating PPP within Ethernet frames, users are able to log on to the ISP network securely. Leased lines, such as T- 1s, and Synchronous Optical Network (SONET) connections do not use Ethernet connections, so they have no need for PPPoE.

A T-3 leased line connection is the equivalent of how many T- 1 connections? A. 7 B. 14 C. 28 D. 112

C. A T-3 leased line connection is the equivalent of 28 T- 1 connections. Each T- 1 consists of 24 channels, so a T-3 has a total of 672 channels (28 × 24), for an overall transfer rate of 44.736 Mbps.

Which of the following is the proper term for a computer with a hypervisor on which you can create virtual machines and other virtual components? A. Guest B. NAS C. Host D. SAN

C. A computer with a hypervisor, on which you can create virtual machines, is referred to as a host. The virtual machines themselves are called guests. Network Attached Storage (NAS) refers to a device containing shared drives that is connected to a network. A Storage Area Network (SAN) is a separate network dedicated to shared storage devices.

Ed is a software developer who has been given the task of creating an application that requires guaranteed delivery of information between end systems. At which layer of the Open Systems Interconnection (OSI) model does the protocol that provides the guaranteed delivery run, and what type of protocol must Ed use? A. Data link layer; connectionless B. Network layer; connection- oriented C. Transport layer; connection-oriented D. Application layer; connectionless

C. A connection- oriented transport layer protocol, such as Transmission Control Protocol (TCP), provides guaranteed delivery of data for upper layer applications. Connectionless protocols do not guarantee delivery of information and therefore are not a good choice. Guaranteed delivery of information is generally not a function of the data link, network, or application layer.

Which of the following cabling topologies provides the greatest number of redundant paths through the network? A. Star B. Ring C. Mesh D. Bus

C. A mesh topology is one in which every node is directly connected to every other node, therefore providing complete redundancy through the network. In a star topology, each node is connected to a central nexus, providing each with a single path to the rest of the network. In a ring topology, each node is connected to two other nodes, providing two possible paths through the network. In a bus topology, nodes are chained together in a line, providing no redundancy.

Which of the following statements is true about the differences between a peer- to- peer network and a client- server network? A. Peer- to- peer networks are inherently less secure than client- server networks. B. Peer- to- peer networks are illegal, while client- server networks are legal. C. On peer- to- peer networks, every workstation is capable of authenticating users. D. On a peer- to- peer network, all workstations must share their resources.

C. A peer- to- peer network calls for each workstation to maintain accounts for authenticating users that access their shared resources. On a client- server network, authentication is centralized. Peer- to- peer networks can be more difficult to administer than client- server networks, but they are not inherently less secure. Peer networks sharing copyrighted content on the Internet are illegal, but it is not illegal to share private resources on a peer- to-peer network. Workstations on a peer- to- peer network are not required to share their resources, but they are capable of it.

Which of the following devices often provides diagnostic testing capabilities at the demarcation point of a leased line Wide Area Network (WAN) service? A. SIP trunk B. Media converter C. Smartjack D. AAAA server

C. A smartjack is a device located at the demarcation point of a leased line that can provide additional functions, such as signal conversion, diagnostic testing, and other capabilities. A Session Initiation Protocol (SIP) trunk is a connection to a Voice over Internet Protocol (VoIP) service provider. A media converter is a local area networking device that connects different cable types to the same network. An AAAA server provides authentication, authorization, accounting, and auditing services for remote access servers.

On a TCP/IP network, flow control is a function implemented in protocols operating at which layer of the Open Systems Interconnection (OSI) model? A. Presentation B. Session C. Transport D. Network

C. Flow control is a process that adjusts the transmission rate of a protocol based on the capability of the receiver. If the receiving system becomes overwhelmed by incoming data, the sender dynamically reduces the transmission rate. In the TCP/IP protocol suite, Transmission Control Protocol (TCP) is responsible for implementing flow control. TCP runs at the transport layer. None of the other layers listed have TCP/IP protocols that provide flow control.

Which DSL (Digital Subscriber Line) technology can adjust its transmission speed based on line conditions? A. HDSL B. IDSL C. RADSL D. VDSL

C. Rate- Adaptive Digital Subscriber Line (RADSL) technology can adjust its rate of transmission based on line conditions. High- bit- rate Digital Subscriber Line (HDSL), Very high- rate Digital Subscriber Line (VDSL), and Internet Digital Subscriber Line (IDSL) do not use rate adaptive transmission.

To which of the following Internet connection types does a specification called DOCSIS apply? A. Dial- up modem B. DSL C. Cable broadband D. ISDN

C. The Data Over Cable Service Interface Specification (DOCSIS) is a telecommunications standard that defines the manner in which data is to be transmitted over a cable television system. DOCSIS does not apply to dial- up modem, Digital Subscriber Line (DSL), or Integrated Services Digital Network (ISDN) connections.

Identify the layer of the Open Systems Interconnection (OSI) model that controls the addressing, transmission, and reception of Ethernet frames, and also identify the media access control method that Ethernet uses. A. Physical layer; Carrier Sense Multiple Access with Collision Detection (CSMA/CD) B. Physical layer; Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA) C. Data link layer; CSMA/CD D. Data link layer; CSMA/CA

C. The Ethernet protocol that handles the addressing, transmission, and reception of frames operates at the data link layer. Each frame includes hardware addresses that identify the sending and receiving systems on the local network. Ethernet uses the CSMA/CD media access control method. Physical layer specifications include the transmission of signals in the form of electrical or light pulses to represent binary code, not frames. CSMA/CA is a data link layer media access control method used by wireless LAN protocols, but not Ethernet.

Which of the following is a common European alternative to the 110 punchdown block used in U.S. telecommunications installations? A. 66 block B. mGRE C. Krone LSA- Plus D. BIX

C. The Krone LSA- Plus is a proprietary telecommunications connector type commonly used in European installations. The 66 block is an outdated type of punchdown block for U.S. telephone systems. Multipoint Generic Routing Encapsulation (mGRE) is a technique for encapsulating network layer protocols; it is not a type of punchdown block. BIX (Building Industry Cross- connect) is a proprietary U.S. telecommunications connection system.

Which of the following is the Maximum Transmission Unit (MTU) size for an Ethernet frame? A. 512 B. 1024 C. 1500 D. 1518

C. The MTU is the largest amount of data (in bytes) that a protocol operating at a given layer of the OSI model can transmit in one packet. The MTU does not include any header and footer fields supplied by that protocol. For Ethernet, the maximum frame size is 1518 bytes, which includes 18 bytes of header and footer fields. Therefore, the MTU for Ethernet is 1500 bytes. Protocols operating at other OSI model layers can have different MTUs. For example, the typical MTU for an Internet Protocol (IPv4) implementation is smaller than that of Ethernet.

Which of the following Transmission Control Protocol (TCP) control bits is set to 1 to initiate the termination of a session? A. SYN B. URG C. FIN D. END E. PSH

C. The termination phase of a TCP connection begins when either the client or the server sends a message containing the FIN control bit with a value of 1. The other control bits listed have nothing to do with the connection termination procedure, and there is no END bit.

The protocols at which layer of the Open Systems Interconnection (OSI) model use port numbers to identify the applications that are the source and the destination of the data in the packets? A. Application B. Presentation C. Transport D. Network

C. Transport layer protocols, such as Transmission Control Protocol (TCP) and User Datagram Protocol (UDP), have header fields that contain the port numbers of the applications that generated the data in the packet and which will receive it. The application, presentation, and network layers do not use port numbers.

Which layer of the Open Systems Interconnection (OSI) model is responsible for the logical addressing of end systems and the routing of datagrams on a network? A. Physical B. Data link C. Network D. Transport E. Session F. Presentation G. Application

C. Network layer protocols (such as IP) contain headers that specify logical addresses for end system communication and route datagrams across a network. The physical layer defines standards for physical and mechanical characteristics of a network. The data link layer uses media access control (MAC) or hardware addresses, not logical addresses. The transport layer uses port numbers, not logical addresses. Session layer protocols create and maintain a dialogue between end systems. Presentation layer protocols are responsible for the formatting, translation, and presentation of information. The application layer provides an entry point for applications to access the protocol stack and prepare information for transmission across a network.

Which of the following is not a technology typically used for a personal area network (PAN)? A. Bluetooth B. Z- Wave C. NFC D. SDWAN

D. A Software- Defined Wide Area Network (SDWAN) is a technology that automates the configuration of WAN routers based on the current mix of traffic. It is therefore not suitable for use on a PAN. Bluetooth, Z- Wave, and near-f ield communication (NFC) are all short- range wireless technologies that are capable of providing communications between PAN devices.

Which of the following devices typically operates at the network layer of the Open Systems Interconnection (OSI) model? A. Proxy server B. Hub C. Network interface adapter D. Router

D. A router connects networks at the network layer of the OSI model. Proxy servers operate at the application layer. Network interface adapters operate at both the data link and the physical layers. Hubs are physical layer devices.

Which of the following terms describes a leased line subscription that provides access to only part of a T- 1? A. E- 1 B. B channel C. OC- 1 D. Fractional T- 1

D. A subscription to part of the T- 1 leased line is called a fractional T- 1 service. This service enables you to purchase some of the 24 DS0 channels in a T- 1 connection. An E-1 is the European version of a T- 1. A B channel is part of an Integrated Services Digital Network (ISDN) service, not a T- 1. An OC-1 is a fiber- optic connection on the Synchronous Optical Network (SONET) service.

Which of the following statements about a wired Local Area Network (LAN) is true? A. Wired LANs support only the star topology. B. Wired LANs support only the star and bus topologies. C. Wired LANs support only the star and ring topologies. D. Wired LANs can support ring, bus, or star topologies.

D. A wired LAN is a group of computers within a small area, connected by a common network medium. A wired LAN can be configured using a ring, bus, or star topology.

Ralph has been contracted to consult for a company that wants to update its legacy Ethernet network to Gigabit Ethernet. On examining the site, he discovers that the network is still using coaxial- based Thin Ethernet. What change in network topology must occur to upgrade the existing network to Gigabit Ethernet using Unshielded Twisted Pair (UTP) cable? A. Bus to Ring B. Ring to Star C. Star to Bus D. Bus to Star E. Star to Ring

D. All coaxial- based Ethernet networks, including Thin Ethernet, use a bus topology. All UTP- based Gigabit Ethernet networks use a star topology. Therefore, an upgrade from coaxial to UTP cable must include a change in topology from bus to star.

Which of the following Wide Area Network (WAN) services provides the fastest transfer rate? A. T- 1 B. E- 1 C. T- 3 D. OC- 1

D. An OC- 1 connection provides the fastest transfer rate at 51.84 Mbps. An E-1 connection is 2.048 Mbps. A T-3 is 44.736 Mbps, and a T- 1 is 1.544 Mbps.

Which of the following Wide Area Network (WAN) technologies uses broadband signaling? A. Digital Subscriber Line (DSL) B. Synchronous Optical Network (SONET) C. Integrated Services Digital Network (ISDN) D. Cable television (CATV)

D. CATV networks use broadband signaling, which enables many signals to occupy the same channel. DSL and ISDN do not use broadband signaling. SONET is a physical layer standard that defines fiber-optic connections.

Which of the following signal types is carried by copper cable? A. Fiber optic B. Microwave C. Infrared D. Electrical

D. Copper cables use electrical signals to transmit data. Fiber optic is a cable type, not a signal type. Microwave signals cannot be transmitted over copper cable. Infrared signals are used only for wireless networks.

Why does DSL (Digital Subscriber Line) technology support faster data transmissions than a standard Public Switched Telephone Network (PSTN) modem connection? A. DSL uses a separate control circuit that provides clear channels for data. B. DSL does not perform Cyclic Redundancy Check (CRC) functions and therefore has less overhead. C. DSL performs only a single analog-to-digital conversion. D. DSL uses a higher frequency range.

D. DSL technology provides higher data rates because it uses frequency ranges that are higher than the standard voice spectrum. DSL connections use 10 kHz and above, whereas the standard voice spectrum uses 300 Hz to 4 kHz. DSL does not use separate control circuits and does not perform CRC functions. Also, DSL technology is strictly digital and does not require an analog-to-digital conversion.

Which of the following Wide Area Network (WAN) services typically uses a switched fabric that was called a cloud long before the term came into general use? A. ATM B. Fractional T- 1 C. SONET D. Frame relay

D. Frame relay is a packet switching service that uses a single leased line to replace multiple leased lines by multiplexing traffic through a cloud. Asynchronous Transfer Mode (ATM) uses a switched fabric, but it is not referred to as a cloud. A fractional T- 1 is part of a leased line that connects two points, so there is no switching involved and no cloud. SONET is a physical layer standard that defines fiber- optic connections; it does not call for switching or use the term cloud.

If you want to allow both voice and data traffic to be transmitted across the same Digital Subscriber Line (DSL) connection, what type of device is required at the customer site? A. A signal terminator B. A Digital Subscriber Line Access Multiplexer (DSLAM) C. A coder/decoder (CODEC) device D. A splitter

D. In a DSL connection, a signal splitter is needed at the customer site to separate the lower frequency voice range from the higher frequencies used by data traffic. The higher frequency signals are handled at the central office by a DSLAM device. Lower frequency signals carrying voice traffic are handled at the central office by a CODEC device. A signal terminator is not required by DSL.

Which of the following best describes the function of a vSwitch (or virtual switch)? A. A vSwitch is a software product that enables a computer with multiple network adapters to function as a switch. B. A vSwitch is a feature in layer 3 switches that enables VLANs on the same switch to communicate with each other. C. A vSwitch is a feature in layer 3 switches that enables VLANs on different switches to communicate with each other. D. A vSwitch enables virtual machines (VMs) running on the same hypervisor to communicate with each other internally.

D. In most virtualization products, when you create multiple virtual machines on one host computer, they can communicate with each other internally using a built- in virtual switching capability. A computer with multiple network adapters can function as a router, but not as a switch. Layer 3 switches can provide virtual routers that connect VLANs together, but not virtual switches. The function that enables VLANs on different switches to communicate is called trunking, not virtual switching.

Ralph is an employee of a company that offers the option to telecommute from home. As a telecommuting employee, he needs to connect to the company network to access client information, transfer files, and send email through a Virtual Private Network (VPN) connection. Ralph is investigating the different Wide Area Network (WAN) services available for the remote connection before he implements one. His home is over 30 years old; the existing telephone wiring was not run through conduit, and the wiring seems to be deteriorating. Ralph has cable television (CATV) service, and his home is also approximately 20,000 feet from the nearest telephone central office. He wants to implement the fastest remote connection service possible, but cost is a factor in the decision. Which WAN technology should Ralph implement? A. A dedicated leased line (fractional T- 1) B. A standard modem- to- modem connection C. A DSL (Digital Subscriber Line) connection D. A broadband CATV connection

D. In this scenario, the best solution is for Ralph to use his existing CATV service for the remote connection. CATV offers faster data rates than standard modem-to-modem service and supports VPN connections. A dedicated fractional T- 1 line is expensive and is not typically used for remote user connections. Since Ralph's telephone lines are not run through conduit and the distance to the central office is more than 18,000 feet, he probably cannot use DSL technology, because it requires good- quality lines and close proximity to a central office.

Which of the following protocols operates at the network layer of the OSI model, but does not encapsulate data generated by an upper layer protocol for transmission over the network? A. IP B. UDP C. ARP D. ICMP E. TCP

D. Internet Control Message Protocol (ICMP) operates at the network layer by sending operational and error messages. It does not encapsulate upper layer protocol data. Internet Protocol (IP) operates at the network layer, but it does encapsulate transport layer protocol data. Transmission Control Protocol (TCP) and User Datagram Protocol (UDP) are transport layer protocols that encapsulate upper layer protocol data. Address Resolution Protocol (ARP) does not encapsulate upper layer protocol data, but it is a data link layer protocol.

Which of the following is not a protocol operating at the network layer of the OSI model? A. IP B. ICMP C. IGMP D. IMAP

D. Internet Protocol (IP), Internet Control Message Protocol (ICMP), and Internet Group Message Protocol (IGMP) are all network layer protocols. Internet Message Access Protocol (IMAP) is a mail protocol that operates at the application layer.

Which of the following is not a protocol that uses tunneling to establish secured links between TCP/IP systems? A. L2TP B. IPsec C. MGRE D. NAT

D. Network Address Translation (NAT) enables workstations on private networks to access the Internet by substituting a public IP address in packets generated with private addresses. Layer 2 Tunneling Protocol (L2TP), IPsec, and Multipoint Generic Routing Encapsulation (MGRE) are all protocols that encapsulate packets in an encrypted form within another protocol to secure the contents.

A client on a TCP/IP network is attempting to establish a session with a server. Which of the following correctly lists the order of the TCP flags raised in the Transmission Control Protocol (TCP) session establishment messages? A. SYN, ACK, SYN, ACK B. SYN, SYN, ACK, ACK C. SYN/ACK, SYN/ACK D. SYN, SYN/ACK, ACK

D. The TCP connection establishment exchange is a three-w ay handshake that uses TCP flags to specify the message type for each frame. The first frame contains a SYN flag from the client; the second frame contains the SYN and ACK flags from the server; and the last frame contains an ACK flag from the client.

Which of the following cable types and connectors are used to attach a television set to a cable television (CATV) network? A. A fiber- optic cable and a Straight Tip (ST) connector B. A coaxial cable and a Bayonet- Neill-Concelman (BNC) connector C. A twisted pair cable and an RJ- 45 connector D. A coaxial cable and an F- type connector E. An AUI cable and a vampire tap connector F. A twinaxial cable and a Bayonet- Neill-Concelman (BNC) connector

D. The cable type and connector used to attach a television set to a CATV network is a coaxial cable with a screw- on F- type connector. Although CATV networks typically use fiber- optic cables and ST connectors for outdoor connections, they do not use fiber for internal connections to television sets. Coaxial cables with BNC connectors are most commonly used for Thin Ethernet LANs, not CATV network connections. Twisted pair cables and RJ- 45 connectors are used for Ethernet LANs and telephone networks, but not CATV networks. AUI cables and vampire tap connectors are used for Thick Ethernet networks. Twinaxial cables are used for SATA 3.0 device and 100 Gbit Ethernet connections, but not for CATV connections.

A company is moving their entire operation to a new building, and part of the plan is to increase the speed of their Internet access by installing a leased T- 3 line to replace their existing broadband connection. The service provider they have selected sends a technician to install the leased line. Which of the following is the correct term for the location in the new building where the technician will terminate the T- 3? A. Patch panel B. Switch C. Firewall D. Demarc

D. The demarc, or demarcation point, is the place where a service enters the building, and where the service provider's physical layer responsibility ends. The patch panel, the switch, and the firewall are all inside the network, and they are the responsibility of the subscriber.

Which of the following hardware components is typically found at the demarcation point of a leased line, such as a T- 1 or T- 3? A. Terminator B. Punchdown block C. 110 block D. Smartjack E. CSU/DSU

D. The network interface device (NID) at the demarcation point of a leased line can be a simple RJ- 45 jack, but many service providers install smartjacks, which can also provide signal conversion, diagnostic testing, and other capabilities. Punchdown blocks, 110 blocks, and Channel Service Unit/Data Service Units (CSU/DSUs) are all telecommunications components located inside the demarc, on the subscriber's private network.

Which of the OSI model layers is responsible for syntax translation and compression or encryption? A. Data link B. Network C. Session D. Presentation E. Application

D. The presentation layer provides a syntax translation service that enables two computers to communicate, despite their use of different bit- encoding methods. This translation service also enables systems using compressed or encrypted data to communicate with each other.

At which layer of the Open Systems Interconnection (OSI) model are there TCP/IP protocols than can provide either connectionless or connection- oriented services to applications? A. Physical B. Data link C. Network D. Transport E. Session F. Presentation G. Application

D. There are two types of transport layer protocols: connection- oriented and connectionless. Connection- oriented protocols guarantee the delivery of data from source to destination by creating a connection between the sender and the receiver before any data is transmitted. Connectionless protocols do not require a connection between end systems in order to pass data. The physical layer does not use connectionless or connection- oriented protocols; it defines standards for transmitting and receiving information over a network. The data link layer provides physical addressing and final packaging of data for transmission. The network layer is responsible for logical addressing and routing. The session layer is responsible for creating and maintaining a dialogue between end systems. The presentation layer is responsible for the formatting, translation, and presentation of information. The application layer provides an entry point for applications to access the protocol stack and prepare information for transmission across a network.

Which of the following statements best describes the difference between Type I and Type II virtualization? A. Type II virtualization requires the host computer to have a processor that supports hardware virtualization assistance; Type I virtualization does not. B. In Type I virtualization, the hypervisor runs directly on the physical computer hardware, whereas in Type II virtualization, a host operating system runs on the computer hardware and the hypervisor runs on top of the host OS. C. Type I virtualization supports up to 256 virtual machines, whereas Type II virtualization supports only 8

D. Type I virtualization requires a separate processor for each virtual machine, whereas in Type II virtualization, the VMs all share a single processor.|B. Type I virtualization does not require a host OS, whereas Type II virtualization does. Both Type I and Type II virtualization can use processors with hardware virtualization assistance, but only Type I requires it. The type of virtualization does not impose any limit on the number of virtual machines supported; any limitations are left to the individual implementation. Both Type I and Type II virtualization can share a single processor among virtual machines.

Which of the following topologies is used by the majority of new Ethernet networks installed today? A. Bus B. Virtual ring C. Mesh D. Hierarchical star

D. Virtually all of the new Ethernet networks installed today use the star or the hierarchical star topology, with one or more switches functioning as a cabling nexus.

Which layers of the Open Systems Interconnection (OSI) model do not have protocols in the TCP/IP suite exclusively dedicated to them? (Choose all that apply.) A. Physical B. Data link C. Network D. Transport E. Session F. Presentation G. Application

E, F. In the TCP/IP suite, the functions of the session layer are primarily implemented in the transport layer protocols: Transmission Control Protocol (TCP) and User Datagram Protocol (UDP). The presentation layer functions are often implemented in application layer protocols, although some functions, such as encryption, can also be performed by transport or network layer protocols.

Which of the following is a correct listing of the Open Systems Interconnection (OSI) model layers, in order, from top to bottom? A. Physical, data link, transport, network, session presentation, application B. Application, session, presentation, transport, network, data link, physical C. Presentation, application, transport, session, network, physical, data link D. Session, application, presentation, transport, data link, network, physical E. Application, presentation, session, transport, network, data link, physical

E. The correct order of the OSI model layers, from top to bottom, is application, presentation, session, transport, network, data link, physical.

Which layer of the Open Systems Interconnection (OSI) model is responsible for dialogue control between two communicating end systems? A. Physical B. Data link C. Network D. Transport E. Session F. Presentation G. Application

E. The session layer is responsible for creating and maintaining a dialogue between end systems. This dialogue can be a two- way alternate dialogue that requires end systems to take turns transmitting, or it can be a two- way simultaneous dialogue in which either end system can transmit at will. No other layers of the OSI model perform dialogue control between communicating end systems.

Identify the organizations that developed the general cable type standards for voice and data communications that are currently in use and identify the document name. A. ANSI/TVA, document C568 B. TWA/ANSI/EIA, document T530-A C. EIA/ANSI/TWA, document 802.2 D. TDA/EIA/TIA, document 802.11 E. ANSI/TIA/EIA, document T568b

E. The three organizations that collectively developed the T568b document, which defines the standard for a structured cabling system for voice and data communications, are the American National Standards Institute (ANSI), the Telecommunications Industry Association (TIA), and the Electronic Industries Association (EIA). All of the other options are not standards organizations or cabling standards.

In which of the following components can a virtual firewall be implemented? A. On a host operating system B. On a guest operating system C. In a dedicated virtual machine D. In a virtual switch E. All of the above

E. A virtual firewall is a service or appliance that performs the same functions as a physical network firewall: packet filtering and monitoring. In a virtual environment, firewalls can take the form of software components installed on a guest virtual machine or a hypervisor host system. A firewall can also be incorporated into a virtual switch.

Which of the following organizations developed the Open Systems Interconnection (OSI) model? A. International Telecommunication Union (ITU- T) B. Comité Consultatif International Télégraphique et Téléphonique (CCITT) C. American National Standards Institute (ANSI) D. Institute of Electrical and Electronics Engineers (IEEE) E. International Organization for Standardization (ISO)

E. ISO developed and published the OSI model to serve as a conceptual model for software and hardware developers. The ITU- T, formerly known as the CCITT, coordinates the development and advancement of international telecommunication networks and services. ANSI is a private organization that administers and coordinates a United States-based standardization and conformity assessment system. The IEEE publishes standards that define data link and physical layer standards. These standards are referred to collectively as the 802 series.

What layer of the Open Systems Interconnection (OSI) model is responsible for translating and formatting information? A. Physical B. Data link C. Network D. Transport E. Session F. Presentation G. Application

F. The presentation layer implements functions that provide formatting, translation, and presentation of information. No other layers of the OSI model translate and format application data.

Which layer of the Open Systems Interconnection (OSI) model provides an entrance point to the protocol stack for applications? A. Physical B. Data link C. Network D. Transport E. Session F. Presentation G. Application

G. The application layer provides an entry point for applications to access the protocol stack and prepare information for transmission across a network. All other layers of the OSI model reside below this layer and rely on this entry point.

A T-3 leased line connection runs at 44736 megabits per second (Mbps). How many separate channels does a T- 3 provide? A. 24 B. 64 C. 128 D. 512 E. 672

|E. A T-3 leased line connection is the equivalent of 28 T- 1 connections. Each T- 1 consists of 24 channels, so a T- 3 has a total of 672 channels (28 × 24).