TCN 4211 final review test questions &
answers 2024/2025
virtual server - ANSWERSAllows a single physical server to host multiple virtual instances of various
operating systems. This allows, for example, a single physical server to simultaneously host multiple
Microsoft Windows servers and multiple Linux servers.
half-duplex - ANSWERSA half-duplex connection allows a device to either receive or transmit data at any
one time. However, a half-duplex device cannot simultaneously transmit and receive.
butt set - ANSWERSA piece of test equipment typically used by telephone technicians. The clips on a butt
set can connect to the tip and ring wires on a punch-down block (for example, a 66 block or a 110 block)
connecting to a telephone. This allows the technician to check the line (for example, to determine
whether a dial tone is present on the line and determine whether a call can be placed from the line).
shielded twisted-pair (STP) cable - ANSWERSSTP cabling prevents wires in a cable from acting as an
antenna, which might receive or transmit EMI. STP cable might have a metallic shielding, similar to the
braided wire that acts as an outer conductor in a coaxial cable.
Frame Relay - ANSWERSA Layer 2 WAN technology that interconnects sites using virtual circuits. These
virtual circuits are identified by locally significant data-link connection identifiers (DLCIs).
cable certifier - ANSWERSIf you are working with existing cable and want to determine its category, or if
you simply want to test the supported frequency range (and therefore data throughput) of the cable,
you can use a cable certifier.
time domain reflectometer (TDR) - ANSWERSDetects the location of a fault in a copper cable by sending
an electric signal down the copper cable and measuring the time required for the signal to bounce back
from the cable fault. A TDM can then mathematically calculate the location of the fault.
multiple-input multiple-output (MIMO) - ANSWERSMIMO uses multiple antennas for transmission and
reception. These antennas do not interfere with one another, thanks to MIMO's use of spatial
,multiplexing, which encodes data based on the antenna from which the data will be transmitted. Both
reliability and throughput can be increased with MIMO's simultaneous use of multiple antennas.
default gateway - ANSWERSThe IP address of a router (or multilayer switch) to which a networked device
sends traffic destined for a subnet other than the device's local subnet.
Domain Name System (DNS) server - ANSWERSPerforms the task of taking a domain name (for example,
www.ciscopress.com) and resolving that name into a corresponding IP address (for example, 10.1.2.3).
physical layer - ANSWERSLayer 1 of the OSI model. This layer is concerned with the transmission of bits
on a network.
authentication server - ANSWERSIn a network using 802.1X user authentication, an authentication server
(typically, a RADIUS server) checks a supplicant's credentials. If the credentials are acceptable, the
authentication server notifies the authenticator that the supplicant is allowed to communicate on a
network. The authentication server also gives the authenticator a key that can be used to securely
transmit data during the authenticator's session with the supplicant.
Basic Rate Interface (BRI) - ANSWERSA BRI circuit contains two 64Kbps B channels and one 16Kbps D
channel. Although such a circuit can carry two simultaneous voice conversations, the two B channels can
be logically bonded together into a single virtual circuit (by using PPP's multilink interface feature) to
offer a 128Kbps data path.
private IP addresses - ANSWERSSpecific Class A, B, and C networks have been designed for private use.
Although these networks are routable (with the exception of the 169.254.0.0-169.254.255.255 address
range), within the organization, service providers do not route these private networks over the public
Internet.
syslog - ANSWERSA syslog-logging solution consists of two primary components: syslog servers (which
receive and store log messages sent from syslog clients) and syslog clients (which can be a variety of
network devices that send logging information to a syslog server).
circuit-switched connection - ANSWERSA connection that is brought up on an as-needed basis. A circuit-
switched connection is analogous to a phone call, where you pick up a phone and dial a number, and a
connection is established based on the number you dial.
,direct-sequence spread spectrum (DSSS) - ANSWERSModulates data over an entire range of frequencies
using a series of symbols called chips. A chip is shorter in duration than a bit, meaning that chips are
transmitted at a higher rate than the actual data. These chips not only represent encoded data to be
transmitted, but also what appears to be random data. Because both parties involved in a DSSS
communication know which chips represent actual data and which chips do not, if a third-party
intercepted a DSSS transmission, it would be difficult for that party to eavesdrop on the data because he
would not easily know which chips represented valid bits. DSSS is more subject to environmental factors,
as opposed to FHSS and OFDM, because it uses an entire frequency spectrum.
carrier-sense multiple access/collision avoidance (CSMA/CA) - ANSWERSJust as CSMA/ CD is needed for
half-duplex Ethernet connections, CSMA/CA is needed for WLAN connections because of their half-
duplex operation. Similar to how an Ethernet device listens to an Ethernet segment to determine
whether a frame exists on the segment, a WLAN device listens for a transmission on a wireless channel
to determine whether it is safe to transmit. In addition, the collision-avoidance part of the CSMA/CA
algorithm causes wireless devices to wait for a random back-off time before transmitting.
Enhanced Interior Gateway Routing Protocol (EIGRP) - ANSWERSA Cisco proprietary protocol. Although
EIGRP is popular in Cisco-only networks, it is less popular in mixed-vendor networks. Like OSPF, EIGRP is
an IGP with very fast convergence and high scalability. EIGRP is considered to be an advanced distance
vector or a hybrid routing protocol.
local area network (LAN) - ANSWERSInterconnects network components within a local region (for
example, within a building).
content switch - ANSWERSCan be used to load-balance requests for content across a group of servers
containing that content. If one of the servers in the group needs to have maintenance performed, that
server could be administratively removed from the group, as defined on the content switch. As a result,
the content switch can help maximize uptime when performing server maintenance. It minimizes the
load on individual servers by distributing its load across multiple identical servers. A content switch also
allows a network to scale because one or more additional servers could be added to the server group
defined on the content switch if the load on existing servers increases.
subnet mask - ANSWERSA 32-bit value (in IPv4) that indicates what portion of the IP address is the
network ID versus what portion is the host ID.
, Interior Gateway Protocol (IGP) - ANSWERSA routing protocol that operates within an autonomous
system, which is a network under a single administrative control. OSPF and EIGRP are popular examples
of IGPs.
service-level agreement (SLA) - ANSWERSA contract between a provider and the client regarding what
services and service levels are to be provided. This also could reference monitoring software on a switch
or router.
routing protocol - ANSWERSA routing protocol (for example, RIP, OSPF, or EIGRP) that advertises route
information between routers, which describes how to reach specified destination networks.
trunk - ANSWERSIn the context of an Ethernet network, this is a single physical or logical connection that
simultaneously carries traffic for multiple VLANs. However, a trunk also refers to an interconnection
between telephone switches, in the context of telephony.
root port - ANSWERSIn an STP topology, every nonroot bridge has a single root port, which is the port on
that switch that is closest to the root bridge, in terms of cost.
current state modulation - ANSWERSOne way to electrically or optically represent a binary 1 or 0 is to
use current state modulation, which represents a binary 1 with the presence of voltage (on a copper
cable) or the presence of light (on a fiber-optic cable). Similarly, the absence of light or voltage
represents a binary 0.
Remote Desktop Protocol (RDP) - ANSWERSA solution that permits the access of an OS desktop remotely
from another device on the network. As an example, this is the default solution for accessing a Windows
system hosted in the cloud via Amazon Web Services (AWS).
single-mode fiber (SMF) - ANSWERSSMF cabling has a core with a diameter large enough to permit only
a single path for light pulses (that is, only one mode of propagation). By having a single path for light to
travel, SMF eliminates the concern of multimode delay distortion.
Dynamic NAT (DNAT) - ANSWERSA variant of NAT in which inside local addresses are automatically
assigned an inside global address from a pool of available addresses.
