Data Comm 2
Which of the following is not a task handled by a router? A router forwards broadcasts over the network. A router can reroute traffic if the path of first choice is down but a second path is available. A router can interpret Layer 3 and often Layer 4 addressing. A router can connect dissimilar networks
A router forwards broadcasts over the network
one watt is equal to how many volt-amps?
1.4
One watt is equal to how many volt-amps?
1.4
What is the maximum allowable distance for horizontal wiring?
100 m
When selecting a punch down block, what block type is more suitable for data connections?
110 block
Standard PoE devices must be provided with how much power in order to function?
15.4 watts
What is the maximum frame size for Ethernet II frames on a VLAN?
1522 bytes
Equipment racks most commonly come in what two widths?
19 inch frame and 23 inch frame
The SSH service listens on what TCP port?
22
What is the industry standard for rack height in rack units?
42U
Select below the band that is not one of the four frequency bands used in the 5 GHz range for wireless LANs: 5.1 GHz 5.3 GHz 5.4 GHz 5.9 GHz
5.9 GHz
Which option below reflects the standard impedance of an RG-6 cable? 50 ohms 60 ohms 65 ohms 75 ohms
75 ohms
Select the maximum allowable distances for horizontal wiring for a span that connects a data jack on a wall to a data closet, and for a span that connects a workstation to the data jack, respectively: 100 m 90 m 10 m 5 m
90 m and 10 m
Which of the following options is not a likely source of electromagnetic interference?
fiber optic cables
The number of times that a wave's amplitude cycles from its starting point, through its highest amplitude and its lowest amplitude, and back to its starting point over a fixed period of time, is known as what term below?
frequency
Which method of transmission allows signals to travel in both directions over a medium simultaneously?
full-duplex
Which method of transmission allows signals to travel in both directions over a medium but in only one direction at a time?
half duplex
If the use of a pre-existing Ethernet infrastructure is desired for a SAN, what Transport Layer protocol should be utilized?
iSCSI
The industry-standard unit for measuring rack height. Standard racks are 42U tall—about 6 feet.
rack unit (RU)
Which network routing protocol is a path vector protocol that sends updates between routers using TCP?
BGP
Amazon and Rackspace both utilize what virtualization software below to create their cloud environments?
Citrix Xen
This field in a frame is responsible for ensuring that data carried by the frame arrives intact, by using an algorithm, such as CRC, to accomplish this verification.
FCS (Frame Check Sequence)
The field in a frame responsible for ensuring that data carried by the frame arrives intact. It uses an algorithm, such as CRC, to accomplish this verification.
FCS (frame check sequence)
True or False: A power fluctuation that results in a temporary dimming of lights is known as a blackout.
False
True or False: Cable that is coated with flame-resistant polyvinyl chloride (PVC) is acceptable for use in plenum areas.
False
What cable types comes in different modes, single mode and multimode?
Fiber Optic
Select the two Transport Layer protocols that are used by SANs: Fibre Channel iSCSI SAS SATA
Fibre Channel and iSCSI
The router on a network that accepts all unroutable messages from other routers is called the:
Gateway of last resort
What IPv4 protocol handles multicasting for tasks such as videoconferencing or teleconferencing?
IGMP
What security encryption protocol requires regular re-establishment of a connection and can be used with any type of TCP/IP transmission?
IPSec
Which type of cloud service model involves hardware services that are provided virtually, including network infrastructure devices such as virtual servers?
IaaS
In order to simplify console access to computers in a rack, what device is typically used to provide a central portal for all devices on the rack?
KVM switch
Ethernet exists at what layer of the OSI model?
Layer 2
What do we call the largest IP packet size in bytes allowable by routers in a path without fragmentation and excluding the frame size?
MTU
A specialized storage device or group of storage devices that provides centralized fault-tolerant data storage for a network is called:
NAS (Network Attached Storage)
A specialized storage device or group of storage devices that provides centralized fault-tolerant data storage for a network.
NAS (Network Attached Storage)
At what layer of the OSI model does the IPSec encryption protocol operate?
Network Layer
At what layer of the OSI model do the 802.11 standards vary?
Physical layer
The standard that describes uniform, enterprise-wide cabling systems, regardless of who manufactures or sells the various parts used in the system, can be referred to by what two options below? hierarchical cabling TIA/EIA-568 IEEE Commerical Building Wiring Standard structured cabling
TIA/EIA-568 and IEEE Commercial Building Wiring Standard
Ethernet is an example of what type of technology?
baseband
Select below the name for the special signal that contains information that a wireless node requires in order to associate itself with an access point:
beacon frame
The radius of the maximum arc into which you can loop a cable without impairing data transmission is known as what option below?
bend radius
What term below is used to describe the outer-most layer of protective covering of a coaxial cable?
sheath
Select the two terms below that are used to describe a UPS that provides continuous voltage to a device by switching virtually instantaneously to the battery when it detects a loss of power: offline UPS standby UPS standby power supply failover power supply
standby UPS and failover power supply
What type of power converter changes the voltage of an AC current, such as when power over the main line from an electric company is changed before being delivered to a home?
transformer
What component of the backbone runs between a building's floors and can be used to connect an MDF and IDF or multiple IDFs?
vertical cross connect
A device that maintains a constant voltage level for either AC or DC electrical energy.
voltage regulator
When using public and private keys to connect to an SSH server, where must your public key be placed? In the authorized keys file under your home directory on your computer. In the authorized keys file on the host where the SSH server is. In the /etc/ssh/keys folder. In the /var/run/ssh/public folder.
In the authorized keys file on the host where the SSH server is.
True or False: A NIC card cannot determine whether the frames it transmits and receives are using IP packets or a different layer 3 protocol, because the NIC does not operate higher than Layer 2 of the OSI model.
True
True or False: Each type of cable has a prescribed bend radius , which is the radius of the maximum arc into which you can loop a cable without impairing data transmission.
True
True or False: The TIA/EIA standard for wall jacks in a work area require that at least one outlet be provided for data and one for voice.
True
When using a site-to-site VPN, what type of device sits at the edge of the LAN and establishes the connection between sites?
VPN Gateway
In a chassis, the path along which air from a cool air source is conducted, past equipment to cool it, and then out of the rack. Typically, air moves from front to back.
airflow
Electrical power flow on a circuit that continually switches direction.
alternating current (AC)
How far away from fluorescent lights or other sources of EMI should cable be installed?
at least 3 feet
Where is a demarc located in relation to the structured cabling of an enterprise environment?
at the entrance facility
The portion of an Ethernet network in which collisions could occur if two nodes transmit data at the same time.
collision domain
Which 802.11 frame type is related to medium access and data delivery, and includes ACK and RTS/CTS frames?
control frames
What routing protocol criteria is defined as the time it takes to recognize a best path change in the event of a network outage?
convergence time
Select the component of enterprise level structured cabling that serves as the location where an incoming network interface enters a building and connects with the building's backbone cabling:
entrance facility
What signal propagation phenomena causes a wireless signal to split into secondary waves when it encounters an obstruction?
diffraction
The flow of electrical power at a steady rate in only one direction.
direct current (DC)
What happens when a router receives a packet with a TTL of 0?
drops the packet and sends an ICMP TTL expired message back to the host
A device that converts DC electrical energy to AC electrical energy. Better inverters will also condition the power, which helps protect sensitive electronic equipment from power fluctuations.
inverter
The combination of a public key and a private key are known by what term below?
key pair
What type of routing protocol enables routers to communicate beyond neighboring routers, allowing each router to create a map of an entire network?
link state
What type of power flaw involves a fluctuation in voltage levels caused by other devices on the network or by EMI?
noise
What security principle provides proof of delivery and proof of the sender's identity?
non-repudiation
A device that changes the form of electrical energy in some way. Four common types are inverter, rectifier, transformer, and voltage regulator.
power converter
During termination of twisted pair cabling, what should be done to ensure minimal cross talk is introduced? No more than 1 inch of the cable should be exposed. No less than 1 inch of the cable should be exposed. Each pair should be stripped of insulation so that it doesn't get caught in the jack. Each pair should be twisted around another pair to reduce cross talk.
No more than 1 inch of the cable should be exposed.
Digital certificates are issued by organizations known as what term?
certification authorities
