CT3 (IS 2018) Flashcards
What does eMTA stand for?
embedded mutimedia terminal adapter
what does CMTS stand for?
Cable Modem Termination System
There are three major music licensing organizations which provide the rights for businesses to play licensed recordings:
ASCAP, BMI, SESAC
A complex number with a resistive and reactive component. It is a function of the frequency of the applied signal, and is unrelated to length
Characteristic Impedance
Business Internet Customer Support a technician can be dispatched within ______, including on weekends and holidays
4 hours
Business TV is not available to venues that:
Charge an admission or entry fee. (However, a monthly or yearly membership is not considered as admission fee. Thus, Business TV is made available to health clubs or special interest clubs.)
(Attenuation x Footage)
Cable Loss
What is a Byte (B)?
8 bits
Short for “picture element.”
Pixel
What DOCSIS standard brought about channel bonding and IPv6?
DOCSIS 3.0
Roughly one thousand megabytes.
Gigabyte (GB)
Roughly 1000 bits.
Kilobit (Kb)
What is a bit?
a single character of data
What numbers do you need to dial in order to place an international call?
011 + country code
Television pictures are displayed in a single pass, instead of the two fields used with interlaced scanning
progressive scanning
Insulate wiring disconnected at the NID with __________or similar if it is going to have continuity back to the eMTA.
Scotchloks
Roughly one million bits
Megabit (Mb)
The variable in calculating attenuation is always
The frequency
Preferred method of coax cable routing
Home Run
Central Office (CO) server that routes calls to other IP-based phones or through the PSTN
Soft switch (Software Switch, VoIP Switch, or CMS)
What website would you direct a customer to for anything business class related?
http://business.comcast.com/
FCC part 76.614
States that any leakage source which produces a field strength of 20 uV/m or greater at a distance of 3 meters in the aeronautical radio frequency bands shall be noted and such leakage sources shall be repaired within a reasonable period of time
Ring voltage for CDV?
60-90 VAC
What is the difference between dB and dBmV?
dB is relative, dBmV is absolute
The opposition a material offers to the flow of electrical current
Resistance (R)
The width of a band of frequencies
Bandwidth
Refers to the telephone only portion of the eMTA. It is typically used for provisioning XFINITY Voice when using the IVR
MTA-MAC
Single pair silver satin utilizes pins ______ of the connector
2 and 3
Large 24-pin connector in which audio is not provided
DVI
Series-6 cable bending radius:
2.5”
Often called Cable Modem MAC, is typically used when provisioning an installation for both XFINITY Voice and Internet
CMAC
The modem waits for an opportunity to communicate with the CMTS. If it does not get an opportunity within about 12 seconds, a __ timeout occurs.
T2
Managed Internet access, available to corporations that have a distributed, mobile workforce of at least 100 persons
Teleworker Internet
The most important part of a Home Theater system is the?
video display
German physicist, investigated galvanic currents and established the mathematical relationship between voltage, current, and resistance
Georg Simon Ohm
CPE that may have REN specifications:
Answering machine, Fax machine, Phone modem, Monitoring devices, Alarm systems
DHCP
Dynamic Host Configuration Protocol
Indicates the pair polarity, detects a short circuit, and indicates the presence of “talk battery” (connection to the network)
Toner
The ____ format utilizes two sequential fields of 540 lines each
1080i
Interlacing produces __ fields or __ complete frames every second
6030
What tools can you use to check polarity on a phone line?
Butt Set and Toner
At 400 MHz, 100 feet of RG6 cable loses roughly
4 dB
What is the supervisory voltage provided by an eMTA?
42-48 VDC
MoCA 1.1 offers ___ ____ MAC rates and __ node network extensions
175 Mbps16
DOCSIS 1.1 added full standardization and quality of service capabilities
April 1999
What is DHCP?
Dynamic Host Configuration Protocol
what are the names of of the two levels of teleworker?
Standard and enhanced
In homes with loop-through wiring, the primary line may have been moved to the ____________ pair because of damage to the _________ pair somewhere in the wall
black/yellow red/green
The flow of electrons through a conductor
Current (I)
(Cable Loss + Passive Loss)
Total Loss
List 2 safety precautions to take before working on phone lines.
Disconnect ILEC, Disconnect eMTA
A return path impairment that can have a severe effect on return path signal quality
CPD
Uses LED backlighting instead of the cold cathode fluorescents CCFL
LED-backlit LCD
Each 10 degree increase in temperature results in a
1.2% increase in attenuation
An _____ jack isolates the alarm panel from the eMTA in the telephone circuit.
RJ31X
At 750 MHz, 100 feet of RG6 cable loses roughly
5.5 dB
When troubleshooting a data device what is the first thing you should check?
dial tone and polarity
What tool can you use to connect your butt set to a modular outlet?
banjo
Includes audio and video input/output ports; Audio input to AV receivers internal preamplifier; Audio output fed to system speakers; Video for selected device is fed from the receivers output jacks to connected video display
Audio/Video Receiver
voltage =
current X resistance
A device that allows the telephone company to route and connect customers to one another
Telephone Switch
Visible fading of luminance between scan cycles on video displays
Flicker
Creates a picture by shooting an electronic beam at a phosphor-coated glass screen
Cathode Ray Tube (CRT)
talk battery
approx 3-9 VDC
When multiple carriers oscillating at different frequencies are transported simultaneously in the same medium
Frequency Division Multiplexing (FDM)
The cable modem has sent a ranging request upstream to the CMTS for transmit and timing information. If the modem does not get a response within 200 milliseconds, a __ Timeout occurs
T3
What are the installation options for Xfinity Internet?
Self installation and professional installation
(Known Level – Total Loss)
Expected Level
When a telephone is on-hook, there is a potential difference of 48 volts between the tip and ring. This is called?
Supervisory or idle voltage
A passive signal splitting device, with minimum signal loss between the input port and the output port (through loss), a specified coupling loss between the input port and the tap port (tap or coupler loss), and very high loss between the output port and tap port (isolation)
Directional coupler
How would a teleworker customer add or disconnect accounts?
Teleworker order center
Enables media files—movies, TV shows, music, and so on—to be played on TV, from various sources like computers, hard drives, the Internet, and media servers
Home Media Streaming
Connect RF to power in order to prevent what?
Ranging
What is the web address for most Comcast modems and eMTAs
http://192.168.100.1
Electromagnetic wave that generally falls in the frequency range of 3 kHz to 300 GHz
RF or Radio Frequency
Passage of outside signal into the cable is known as what?
Ingress
What are the 3 troubleshooting areas in CDV?
Before eMTA, At eMTA, After eMTA
Why is it improper to cut a center conductor a second time to (trim it) to fit a fitting?
A jagged center conductor can scratch the contacts inside the F-port creating reflections.
What frequency range is tested in a downstream Ingress resistance test?
88-108 MHz(FM Band) downstream
The twists in CAT5 wire help to prevent these 2 things?
crosstalk, noise
What is ICFR?
In Channel Frequency Response
Damage to the copper or silver skin of the center conductor will directly affect ____ _________ signals
high frequency
Out of the following colors: Green/Red Yellow/Black list the tip and ring.
green-tip, red-ring, yellow-ring, black-tip
A general term for non-projection types of TVs, which include conventional tube TVs and flat-panel plasma and LCD TVs
Direct View TV
Older wiring is often referred to as ____________, or Category 1 (CAT 1) wire.
station wire
An increase of 3 dB _______ the signal power
doubles
How many pairs should there be in a fax machine flat satin?
1 pair
The method of displaying television pictures in which the picture is displayed in two halves (one of odd-numbered lines, one of even-numbered lines)
Interlaced scanning
A term used in IP telephony for methodologies and transmission techniques that manage the delivery of voice, using IP packets
Voice over Internet Protocol (VoIP)
What does the term POTS mean?
Plain Old Telephone System
A home run system is also known as what?
Star topology
Cable modems communicate with the CMTS every _________ to characterize network conditions
20 seconds
Keenness and depth of perception, discernment, or discrimination especially in practical matters
Acumen
Ideal if there is little or no space for a TV or projector; Can be hung on the wall; Can be plasma or LCD
Flat Panel
Performs a function similar to that of a cable amplifier’s equalizer. However, instead of equalizing the entire 50-860 MHz downstream or 5-42 MHz upstream, it deals with just a single channel.
Adaptive Equalization Technology
Also known as Touch-Tone, this form of audio signaling was introduced by Western Electric in 1963
DTMF: Dual-tone multi-frequency signaling
What frequency range is tested in an upstream spectrum test?
5-42 MHz
What are the three main components of a home theater system?
Audio, Video, Environment
The total REN value in an individual circuit should not be greater than?
5
DOCSIS supports frequencies anywhere between:
88 MHz and 860 MHz
What is QAM?
Quadrature Amplitude Modulation
Aspect ratio of HDTV
16:9
Signal leaking out of the system is known as what?
Egress
Coax attenuation specifications are based on:
100 feet of cable at 68 deg F
What four services are business class TV customers not eligible to receive?
DVR, VOD, Impulse Pay Per View (IPPV), Premium channel
The difference between transmitted and received power resulting from the loss through equipment, lines, or other transmission devices; usually expressed in decibels.
Attenuation
A return path problem that is caused by the corrosion of dissimilar metals?
CPD
All lights flashing on an eMTA indicate what type of problem?
Foreign Voltage
What is our loop current?
23-40 mA
MHz (Megahertz):
Equal to one million Hz. Video signal bandwidth is typically expressed in megahertz
The twists in Category 3,5 and 6 wire help prevent __________ and cancel out noise that might be induced onto the wire from adjacent pairs or exposed wire.
cross talk
_________circuits are almost always used in IP voice telephony
Loop start
Signals propagate through either of two mediums
guided and unguided
What ensures interoperability of cable modems from various manufacturers?
DOCSIS
Is a measure of the ability of a circuit (often an amplifier) to increase the power or amplitude of a signal from the input to the output
Gain
A telephone line dedicated to a specific subscriber. This line sends signals through the system, based on a subscriber making and receiving calls.
Subscriber Line
Aims to support capacities of at least 10Gbit/s downstream and 1Gbit/s upstream
DOCSIS 3.1
Anytime an RF signal changes by 3 dB, the signal power is either _______ (+3 dB) or ___ __ ____ (-3 dB)
doubledcut in half
Delay associated with inconsistencies, or impairments, in the data transport stream.
Latency
Allows customers to link home TVs from any PC or hand-held device
Slingbox
What is the acceptable measurement for both the upstream spectrum test and the Ingress resistance test?
-30 dBmV or lower
Images result when electrically charged gases illuminate colored phosphors
Plasma
What must be placed between the eMTA and the customers telephones if they have an alarm system?
RJ31X
6P6C connector -
6 wire - RJ25 – three phones
What is CRT?
cathode ray tube
how any levels of teleworkers are there?
2
Series-7 cable bending radius:
4”
CPE
Customer Premise Equipment
High frequencies travel in the very ____ of the center conductor
skin
The property of higher frequencies travelling on the outer portion of a conductor is called the ____ ______
skin effect
Business Voice is transported over _____________________________, giving customers the clarity they expect.
Comcast’s private, advanced broadband network
Business customers are required to sign a ______________________ in order to establish service.
service order agreement/contract
In legacy telephone networks, talk battery and ring voltage come from the?
Central Office
How far should seating be away from TV for Optimum viewing in a Home Theater setup?
Seating should be two times the diagonal wide-screen TV away from TV (example: seating should be 84” away from a 42” TV screen)
The number one cause of ingress and egress occurs where in the system?
Drop system
The transfer of energy from one device to another is most successful when both devices are of the same
Impedance
At 50 MHz, 100 feet of RG6 cable loses roughly
1.5 dB
How much REN do we suppoprt?
5
5 factors of attenuation
Diameter of center conductor, Dielectric, Frequency, Temperature, Length of cable
The demarcation point for Small Business Voice services is?
Network (left) side of the 66 block or if there isnt a block, The RJ telephone connector on the back of the eMTA
The amount of pressure required to cause one ampere of current to flow through one ohm of resistance
One volt
Allows an alarm panel to control access to active phone pairs, and seize those pairs even if the customer is using the telephone
Line seizure
The number of times per second that the scan sequence is repeated from the top of the display
Vertical Scan Rate
what is the major difference between the two teleworker service levels?
speed
List the 4 main types of displays
Direct view, Rear Projection, Front projection, Flat Panel
_____ ___________ utilize more of the cross-sectional area of the conductor and are more forgiving when it comes to imperfections in the copper plating
Lower frequencies
Contrary to popular belief, the handset cord is not a ______________ It has been erroneously referred to as an RJ22, RJ10, or RJ9. It is simply a unique sized 4P4C connector designed for the handset.
registered jack
Worldwide network of public circuit-switches used by traditional, local, and long-distance companies
Public Switched Telephone Network (PSTN)
After __ T4s, the cable modem will reset
16
The ability to make good judgments and quick decisions, typically in a particular domain
Business acumen
MoCA 2.0 operates in the ___ - ____ MHz frequency range
500 - 1650
List 2 types of call forwarding.
Selective, Variable
What connection type provides both audio and video?
HDMI
Separating successive frames into two types of video information—that which remains unchanged from frame to frame, and that which is updated frame to frame
Digital Compression
Separating successive frames into two types of video information is also known as what?
compression
Suite of applications that enable customers to enjoy the services they have from Comcast on as many platforms as possible
Converged Products:
Typically private/professional businesses where food and/or alcohol is not sold for immediate consumption/not the main source of revenue.
Private View
The number of scans from the left side of the display to the right and back that occur in one second
Horizontal Scan Rate
What does DLNA stand for?
Digital Living Network Alliance
The voice portion of the eMTA can interpret both
DTMF and pulse signaling
If the power light is flashing on an eMTA it indicates what?
AC power failure
DOCSIS
Data Over Cable Services Interface Specification
Passage of an outside signal into the cable; can result in noise and disruption of the desired signal
Ingress
Tiny dots that convey light and combine to form a video picture
Pixel
ILEC
Incumbent Local Exchange Carrier
What is it called when packets are received in the wrong order?
jitter
Ground loop issues are basically caused by
A 60-cycle AC component in the audio connections
6P2C connector -
2 wire – RJ11 – one phone
The insulating material separating two conductors such as that between the center conductor and sheath in a coaxial cable
Dielectric
An eMTA or modem that has not been activated receives a ____________boot file which allows it to communicate with our network but not surf the Internet
walledgarden
Equation for calculating Exact Loss
Cable Loss + Passive Loss = Total Loss
___________ circuits can be noisy and more susceptible to migration and corrosion
Ground start
A signal of 0 dBmV corresponds to
1 mV across a 75-ohm impedance
What frequencies are assigned to the downstream and upstream?
Up- 5-42 MhzDown- 54-1002 Mhz
MoCA 1.1 operates in the ___ – ____ MHz frequencyrange
500 – 1500
Consisting of a separate projector (typically placed on a table or ceiling-mounted) and screen; Can display images up to 20 feet across, or larger
Front Projection
It is the process of modifying IP address information in IPv4 headers
NAT
What does MoCA stand for?
Multimedia over Coax Alliance
6P4C connector -
4 wire – RJ14 – two phones
Load-sharing technique for logically combiningmultiple DOCSIS channels
Channel Bonding
In a ____________ wiring configuration, the twisted-pair coming in from the NID goes, consecutively, through all the phone jacks
loop-through
1 Baud equals ____, thus 9600 Baud is _______.
1 bps, 9.6kbps
A network architecture developed by the cable industry, which typically uses fiber optic cables to bring signals to selected areas of the system called nodes, which are usually based on the number of subscribers to be served
Hybrid Fiber Coax (HFC)
In earlier pulse dialing systems, noise generated in the copper pairs could be interpreted as a pulse by the switch rendering:
Wrong telephone numbers
The number 1 cause of ingress and egress?
Poorly installed connectors
Includes, but is not limited to, locations where the bulk of the revenue is derived from the sale of food and/or alcohol
Public View
Provides a physical path along which the signals are transported; such as those used in cable TV
Guided media
The adaptive equalizers are sent fresh commands for equalization every?
20 seconds
Internet phone services transmit calls over a ______ network.
Public
Creates images by passing light through a layer of liquid crystal sandwiched between two panes of polarized glass.
Liquid Crystal Display(LCD)
4-pin video only connector
S-Video
Operate components located throughout the household; Generates signals of given radio frequency
RF Remotes
A site where telecommunications companies (such as cellular and long-distance providers) physically interconnect their systems with other networks (such as local telephone companies or cable companies)
Point of Presence (POP)
A flow of IP data supplied to a processor at a rate fast enough forreal-time decoding
Streaming
The condition that results when two components of a system are operating at a different impedance
Impedance Mismatch
In North America, a ____ pattern is the standard ring cycle.
2-4, two seconds of ring voltage followed by a four-second pause
4P4C connector -
4 wire (handset coil cord)
A measure of the received carrier strength relative to the strength of the received noise
Carrier to Noise (C/N) ratio
A condition caused when packets are not received in the correct order, or when they take too long to arrive at their destination.
Jitter
Three components of an electrical circuit:
Voltage, Current, Resistance
Once a cable modem is online, it continues to communicate with the CMTS. The modem watches for Keep Alive requests from the CMTS. If it does not receive one after 30 seconds, a __ timeout occurs.
T4
MPEG identifies and removes what type of information between successive frames of the picture?
Redundant / Static
Comcast has allocated downstream DOCSIS carriers to be located in the higher end of the downstream bandwidth, somewhere between:
500 and 700 MHz
Be sure that the alarm system is in ________ before beginning work, to ensure that an alarm is not triggered
Test Mode
MoCA 2.0: offers net throughput MAC rates of ________(baseline mode) and _______ (enhanced mode)
400 Mbps800 Mbps
Uses an RCA connector to Analog Audio
Stereo Connection
Identifies and removes redundant information between successive frames of the picture
MPEG compression
RCA wiring that uses Yellow Red and White connectors
Composite video
Latent or out-of-sync audio
Lip-Sync
What is the measure of voice, data and or video quality provided to a customer called?
Quality of Service (QoS)
One coulomb passing a given point in one second is equivalent to
One amp
With station wire the_____ and___ wires are used for the primary line.
green, red
In a home-run wiring configuration, also known as ____, each outlet is fed directly from a central location
star
Boosts low level signals from the components to the speakers.
Amplifier
DOCSIS 3.0 released; it supported enhanced upstream and downstream transmission speeds and Internet Protocol version 6 (IPv6).
August 2006
A customer can access Enhanced Voicemail while away from home bypressing
, once the greeting begins
What is a rugged, inexpensive to repair bandwidth versatile transmission medium?
Coaxial cable
The different types of audio formats are:
Mono, Stereo, Surround Sound
The three main components of a Home Theater system are:
Audio, Video, Environment
Two versions of Business TV:
Private ViewPublic View
Can be water or the air around us. The signal is transmitted from a transmit antenna to a receive antenna
Unguided media
The modem scans the downstream QAM channels, looking for an upstream channel descriptor. A __ occurs if the cable modem does not find one within a few seconds
T1
Some ILECs utilize “______________,” a service that keeps talk battery on the pairs even if the location no longer subscribes to their phone service
soft dial tone
Formula for voltage
E=IxR
What is the 4 step troubleshooting process?
Identify, Isolate, Repair, Verify
What does EDTV stand for?
Enhanced Definition TV
What does VOIP stand for?
Voice Over Internet Protocol
The common progressive scan standards that you will see are:
480p, 720p, and 1080p
Toslink or EIA-J are types of what?
Optical Digital Audio connectors
Only _________ alarm systems should be connected to the phone service
monitored
DOCSIS 2.0 released, to meet the demand for enhanced upstream transmission speeds
December 2001
A standard for home entertainment networking in which existing subscriber drop coaxial cabling and components are used to interconnect set-top boxes
MoCA
All FM radio stations transmit in a band of frequencies between:
88 and 108 MHz
Multiple carriers oscillating at different frequencies transported in the same medium is what?
Frequency Division Multiplexing
What does REN stand for?
Ring equivalency number
When an eMTA is upgrading firmware what lights are flashing?
U/S and D/S
What type of cable is needed to backfeed an eMTA to a wallplate?
electrically straight
What is the resolution of EDTV?
480p
Uses an RCA connector to carry Digital Audio
SPIF coax cable (Coaxial Digital connection)
What is an internet product for companies that have a mobile workforce?
Teleworker
There are three significant considerations in a Home Theater application
Audio quality, Audio formats, Audio equipment
What is the delay between transmission and arrival of a packet?
latency
Some routers come with a ___________option which, when enabled, essentially disables the networking functionality and the gateway basically becomes a modem.
Bridge Mode
What is the name of the dial tone a customer will hear when they have voicemail?
stutter
Projects light from microscopic mirrors onto big, widescreen, rear-projection TVs (or micro-displays)
Digital Light Processing(DLP)
what are four benefits to an employer who uses teleworker?
Single contract, unified billing, online ordering and management, business class customer support
A measurement of how consistent the signal response is from the beginning to the end of the channel space
ICFR
8P8C connector -
8 wire – RJ45 - Ethernet
The cumulative effect of ingress from multiple homes is known as what?
Funnel effect
DOCSIS 1.0 issued
March 1997
Name four COMCAST business services
TV, Phone, Internet, Teleworker, (smartoffice)
What defines where COMCAST may physically disconnect a customer from the ILEC network?
Interconnection Agreement
The electromotive force (or pressure) that causes electrons to flow in a circuit
Voltage (E)
what are four benefits of teleworker for employees?
Multiple connections, comcast.net email, after hours use, Portal services
A subunit of a larger unit called the bel:
decibel
Exceptions to opening the alarm panel:
When you do not know the color/pair of inside wiring that has been previously used to supply dial tone from the NID to the RJ31XWhen you need to isolate a trouble condition
Voice packets are given priority over other types of data traveling within the Comcast network. This managed delivery ensures high-quality voice packet interpretation.
Dynamic Quality of Service (DQoS)
Excess debris left in a punch down block that can cause a short is known as?
shiners
Standard television pictures are composed of ___ horizontal lines that scan across the screen in less than the blink of an eye
480
The Top 5 Types of Connector Problems
- Moisture damage2. Long/short center conductor3. Connector not tightened to port4. Braid removed or too short/long5. Improper connector for cable type
Upstream carriers are currently located somewhere between:
5 and 42 MHz
Latent or out of sync audio is known as?
Lip sync
List the 3 pairs in order of older station wire?
Green/Red Black/Yellow White/Blue
