What is the assume loss between taps on feeder cable
.5 dB
What is CLI
A figure of merit derived mathematically from the number and severity of leaks in a cable system
What is a figure of merit derived mathematically from the number and severity of leaks in a cable system
CLI
Whats the most common cause of signal leakage
Poorly install F connectors
What are unwanted signals that enter into a network can create
Beat patterns
What forms diagonal lines on the screen
Ham and other broadcast AM carriers
What modulations can cause lines to appear to move
FM radio interference
What causes ghost
Off Air frequencies that come into the line
Following Ghost
Appear to the left of the picture
Caused by a reflection on the cable system caused by poor return loss at the reflecting device and poor directivity at the the tap or device feeding the set
Caused by a reflected signal arriving at the headend recieving antenna AFTER the desired signal
Leading Ghost
Appear to the right of the picture
When ingress allows a local broadcast enter ALONG with the channel supplied by the network
Co Channel Interference
2 or more different tv stations are recieved by the same antenna
Zero Beat
A method of reception using an RF current of the proper magnitude and phase relation so the recieved voltage is of the same nature as the original wave
Frequency Offset is used when stations are too close to each other.....diagonal lines will appear if there is co channel interference....if no offset the two stations would be very close but not exactly the same frequency causing zero beat
Return Path Interference
Return direction can suffer ingress from transmitters operating in the upstream frequency bandwidth
Items in the home can travel back through the drop and on to the headend
CB
Voice of America
Amateur Radios
Tv's
Thermal Noise
Any noise added to the line which is caused by an increase or drop in temperature. 0.17dB per 20 degrees.
C/N ratio
difference between carrier level and noise level both measured in dBmV
C/N formula and rules
C/N = L1 (NF- 59.2)
Types of Distortions
XMOD Cross Mod - Verticle Bars
Discrete 2nd Order
Discrete 3rd Order
Composite 3rd Order
Composite Second Order
XMOD
Cross Modulation....Occurs usually from power passing chokes in passive devices....causes verticle bars on picture
Discrete 2nd Order
The sum of two carrier and their harmonics that do not cause a negative frequency
Discrete 3rd Order
The sum of three carrier and their harmonics that do not cause a negative frequency
Compositie 3rd Order
CTB
Composite Triple Beat
Doesnt occur on ch 5 or 6
the energy bundles the triple beats
Composite Second Order
The energy bundle of 2nd beats ...but only occurs 1.25 above the video carrier....only 30 beat may interfere in a 77 channel plan
Video carrier are seperated into
6MHz increments
Foward path -
Return Path -
Fo - 50MHz - 1GHz
travels Down
High
Re- 5MHz - 42 MHz
travels Upstream into system
Low
Digital algorithm that allows you to send information by shift in 90 degree incements with 4 phases
QPSK
Digital scheme that allows you to send 2 pieces of information at the same time by changing phase and amplitude
QAM
S/N ratio
20 log 10 (Vs-Vn)
Whats an important key about S/N and the formula
Vs should be higher than Vn. If not the noise from active devices will interrupt with service
NPR
Noise Power Ratio
What is Noise Power Ratio?
It measures activity in unused portions of the system usually using an unscrambled signal.....using filter like white noise filter and notch filter to measure the trough that occurs when testing
Measure the ratio of error power(strength) to the average power of ideal QAM signal
MER
What test is best to find out a problem that may occur before it shows up visually
Mer
How often an error occurs is given amount of data
BER
FEC
Foward Error Correction
Additional bits added to correct data impairments
High Pass Filter
Passes high frequency but atteunates low (return) frequencies
FDM
The carrying of different frequencies on one cable line due to the seperation of frequencies in cable system...Frequency Division Multiplexing
Noise, modem, ingress signals combining in a node to cause problems on the return (upstream) signal.
Funneling Effect
Proof of performance
47 part 76.605...24 hour test of foward signals mandated by FCC
Aluminum, contains seizures and mechanism protects electronics and prevents rf leaking in and out
Housing
provides mean of physically attaching electronics to housing, also refer to as the mother board, and provides dc power to modules
Chassis
Seperates and combines rf and ac power
power filter
seperates and recombines foward and return, return establishes a band split
diplex filter
Attenuates foward signal to bring in spectrum of acceptable signal
Pad (Attenuator)
Compensates for unequal attenuation of different frequencies
Equalizer
Used for low noise figure...amps the foward signal through truck and lines
Foward Amp Module
Equalizes undesired peaks and valleys within the amp
Response EQ/ Mop Up
Used to compensate for fluxuations in input signals
Automatic Gain Control
similar to AGC but maintains proper tilt due to weather
Automatic Level and Slope
used in tree and branch...recieves signal from truck and amplifies foward signal (usually with higher output than truck signal
Bridger Amp
Boost return usually 20dB and usually built with return equalizer
Return Amp
Used to fix reverse tilt in higher tap values
Equalizer
Used to fix reverse tilt in lower taps
In line conditioner
used to insert ac power into a network for power devices
Power inserter
The first picture in the sequence.....a single compressed pciture that contains all spatial information
I picture
calculated by comparing the previous and successive pictures and recording only the changes...based on nearest I or P pictures
Predictive picture
uses BOTH past and subsequent pictures as references to CALCULATE the compressed data
Bi Directional Pictures
a cryptographic protocol for protecting audio/video entertainmentcontent from illegal copying, intercepting and tampering
Digital Transmission Content Protection....DTCP
Prevents and Distorts copies made over an ANALOG connection between a source player and recording device
Analog Copying and Piracy....ACP
protection of content by requiring certain critera to be met before granting access to this content
Conditional access
Digital Comnpression
works by seperating picture into two types of information...the same and one that changes
Codec
Video Codec
Compression Decompress............
A device or software that enables compression/decompression for digital video
tapping device providing isolation between tap and output terminals
directional coupler
Channel deletion filter
is used when one or more channels need to be deleted and new channels need to be reinserted
places baseband signal onto standard rf channel carrier
Video modulator
Drop and insert
process that diverts a portion of multiplexed aggreagte signals at an intermediate point and inserts a different signal for subsequenttransmission in the same position
room that acts as the hub for various telecommunications services
communication room
used for data application
110 block
used as standard phone (nid)
66 block
go between emta and 66 block
rj 21x jack
mushroom spool
helps avoid kinks and sharp bends...should leave 1-3 ft excess
P.O.S
baud rate of 9600 or dial 9 if problem occur...uses internal modem to transmit sales via phone
muliple buttons are needed to access different stations...usually need to push a number or pulse to use outside line
Key/PBX telepone station
Base band signal onto key pbx systems
Music/message on hold device
telementry wiring
White
Brown
Blue
Orange
Green
Black
red
Battery Pack
48 VDC
50 Watt
Minimum point of Entry
Commercial Demarcation Point
For video it is ground block or tap in communication room
For HSD it is the ethernet port on comcast owned equipmet or rf barrel on customer owned modem
For BCV is left side of the 66 block
or rj21x
acts as focal point that connects multiple computer to 1 lan
Switch
a managed hard drive connected by the LAN that can be accessible by anyone on the internet as defined by a company's administrator
NAS
connects building data wiring to ethernet switch
network patch bay
Less interference and certified for data applications
110 punch down block
A network begans with this
Access Point
Network Speed
How quickly computers on a netwokr can communicate and share information
Optimum Wireless
- place router in family room or office
- wireless card antenna point to wirless router
- DONT put router near outside wall
- If using laptop outside put router near a window
802.11a
different frequency 5.0
low range 25-75 ft
same speed as g standard 54mbps
802.11b
802.11g
802.11n
B has lowest speed 11mbps
same range 100-150 ft
all have same frequency 2.4Ghz
N has fastest speed 100Mbps or faster
N has largest range 160ft
*All backwards compatible....n works with g....g works with b
Parts of a virus
Replicate - copies itself onto programs
Event watching - Checks for certain triggering conditions
Camouflage - Disguise themselves to avoid detection
Delivery - When triggering condition are met it delivers the payload
Types of viruses
Email - in email or attachment
Executable (exe) - runs with other programs
Worm - small software that finds security holes
Trojan Horses - Claims to be one thing but is really another
Heuristic Detectors
look for sections of code triggered by time or date events, routines to search for files such as .com, .exe, .bat, and vbs: as well as, disk writes that bypass the operating systems
look for sections of code triggered by time or date events, routines to search for files such as .com, .exe, .bat, and vbs: as well as,disk writes that bypass the operating systems
heuristic detectors
what is the first thing you do in a cdv trouble call
unplug the phone line from the emta
program on hard drive that sends info about you and how you use your pc to marketers
spyware
displays advertising for products that it think you may be interested in buying based on your browsing
Adware
unsolicited bulk email
spam
SMPT 550
email address is not a vaild one
Hackers
people who r able to exploit a system or cain unauthorized access
What is the best way to prevent a hacker from access a customers system?
A firewall. A hardware or software.....a router is an example of a hardware firewall
a range of malicious software....usually changes browser settings like the home page
Hijacking
A hardware of software placed between the customers PC and internet
firewall
Firewall rules
Packet Filtering - examines each packet and its ORIGIN
Proxy- examines all data based on FILTERING RULES
Stateful inspection - compares KEY PARTS of the packet to a safe database
examines each packet and its ORIGIN
Packet Filtering
examines all data based on FILTERING RULES
Proxy
compares KEY PARTS of the packet to a safe database
Stateful inspection
Blue screen errors tha desplay the words Memory Dump along with a cryptic set of hexadecimal address....This error is indicitive of a major problem with the operating system and the best solution is to reinstall windows
Memory Dump
indicates a problem with a device or driver. This is the XP version of the BSOD. The error message usually appear at start up and can have numerous causes
Stop error
HTTP port
25 and 80
what is FTP
port 21
file transfer protocol
protocol used for transferring files
What is a portion of a network that shares a common address component / all devices whose ip addresses have the same prefix
subnet
What is a signal splitting device that plugs into a trunk/bridger chassis (used at output of bridger module)
feedermaker
What is an Internet access gateway server for guests, found between the modem and the router and the rest of the network
IP3net aceess server
What allows a group of phone stations to access a common set of telephone lines
key system
What is used where cable doesn't quite reach- to extend distances- to extend the reach of cable I in a ped
extension fittings
What converts ethernet back to coaxial signal
mega port gateway (connects with IP3 server)
What is a high speed line or series of connections that form a major pathway within a network ?
backbone
What forwards requests for a particular ip port pair to another ip port pair (commonly used on publicly connected hosts to make an internal service available to a larger network)
PAT - port address ranslation
What does the green wire mean in telemetry
return
System noise , CSO , CTB , distortion due to lasers, clipping modulator problems is caused by what
Non-tranisent (not short)(long period of time) ingress
pop3
port 110
deny aim access
port 5190
ping
ping website
EOL
end of life
types of IP's in subnetworks
network
routable
gateway
broadcast
Symmentry Advantage
equal upspeed and downspeed
TFTP
Trivial File tranfer protocol
protocol used to assign IP's
RIP- routing information protocol
Static Routes
allows devices routed by comcast business gateway to communicate with the seperate subnet of a router connected to a lan
Firewall option
only disable firewall function on the gateway at customers request when customer has there own equipment
Port Fowarding
Allow you to DIRECT INBOUND traffic to connect to a specific apllication or computer within a lan
INBOUND rule lets you open a window so that traffic can be direct to your computer based on the port number
Port Triggering
Provides the ability to dynamically open a specific INBOUND PORT based on REQUEST FROM a local computer or user
similar to fowarding that it Opens a window for traffic to enter BUT when the traffic stops the window closes
HTTPS
Port 443
True Static IP port Management
OPEN and CLOSE specific INBOUND ports to connected computers or firewalls configured with a public routable IP address (for use by static IP customers only)
COMPLETELY blocks all ports except some or completely open all ports except some
Port Blocking
Enables you to restrict specific local hosts from accessing particular Intrnet application by IP address and logical port.
ex...You can use 5190 to block aim access
Website blockinh
set up rules to block certain internet based content. Listed by website or keywords
DMZ
Allows one IP address or computer to be placed between the firewall and the internet....removing the protecting of the firewall.....Risky but allows open access to internet
MAC
Media Access Control
a unique number that is assign by manufacture to any network device which allows the network to identify it.
Ports
65535 are available
1- 1023 are well known ports
1024 - 49151 - registered ports
49152 - 65535 - dynamic and/or privite ports
Tracert IP
how to do a traceroute
used for tracing how many hops it takes to go from one computer to a website
locates and translates domain names
dns
A group of computer geographically far but are connected
Wide Area Network WAN
A groupe of computer geographically close connected to ONE NETWORK using the same communication device....A home to a office of many computers
LAN
A technique in which several computers share a SINGLE IP fo access to the internet
Network Address Translation
a secure connection to an organization's private network using the public internet
Virtual Private Network VPN
Subnetworks (Subnetting)
concept of partitioning large networks into smaller segments
Subnet Addresses
example : {150.215}. {017.009}
150.215 defines network
017.009 defines the device or host
for easier internet travel
/30
1 routable IP
subnet mask will be 255.255.255.252
/29
5 routable IPs
subnet mask will be 255.255.255.248
/28
13 routable IP's
subnet masks will be 255.255.255.240
AC fail
White
Battery Missing
Blue
Battery Low
Orange
Rplace Battery
Brown
Flashing lights
foreign voltage
light flashing slowly
line card error
Data lines should only be used for ?
Fax
Call Hold
*52
Group Make busy
*232
*233 deactivate
Call foward Selective
*63
*83 deactivate
Call fowarding variable
*72
*73 deavtivate
Cancel call waiting
*70
Call screen
*60
*80 deactivate
Call Block
*67
Call rejection
*77
*87 deactivate
speed dial 8
*74
speed dial 30
*75
Do not disturb
*230
*231 deactivate
NGT
New Global Telecom (outsourced vendor)
used to pre provision phone number
used for post provision of features to phone
ATS
Advanced Technical Services
TTS
Trouble Ticket System
What callng feature allows different phone numbers to reach the same phone line with different ring patterns
Distinctive ring
deactivate *81
A customer is responsible for placing their own Ad in the yellow pages
True
Customers can automatically distribute incoming calls to two or more extentions using what calling feature
C) hunt groups
Direct call pick up
*97
allows cutomers to pick up or barge in on a call to another co worker using a feature access code