Block 8 Flashcards
The interface option has a single conductor with a ground return conductor
Unbalanced
What are the two basic interfacing concepts
Balanced and unbalanced
This interface option has the impedance of 2 signal conductors with respect to a reference
Balanced
Which interface option supports higher data rates and greater distances
Balanced
What is the unbalanced standard that supports asynchronous data flow
RS 232/ EIA-232D
Balanced interface used for both synchronous and asynchronous
RS-530
Oldest and Most commonly used standard for DTE/DCE
RS 232/EIA 232D
Sort of hybrid standard between balanced and unbalanced
V35
Most common standard for network
EIA/TIA 568B
Balanced standard that specifies physical/electrical properties of twisted pair cable/connected hardware
EIA/TIA 568 B
Expresses information by discretely changing the voltage on the transmission line
Digital signal formats
One polarity with respect to ground
Unipolar format
Two polarities, no set rule which polarity will be present at a digital 1 or 0
Bipolar format
Type of bipolar signal that sends all digital 0s at 0v and alternates the digital 1s from positive to negative polarity
Alternate mark inversion (AMI)
Analog signal that has digital information coded on it
Quasi-analog
Regular rhythmic reoccurrence of a clocking pulse at a predetermined rate and will determine how long a bit lasts.
Timing
3 common types of digital timing method
Asynchronous
Synchronous
Isochronous
Each character is turned into a string of bits… Used start and stop bits
Asynchronous timing
What was once the most common form of digital transmission
Asynchronous timing
Hardware flow control is sometimes referred to as
Request to send / clear to send
Rts/Cts
Software flow control is known as
Transmit on and transmit off
Xon-Xoff
When data is transmitted with reference to an external clock signal
Synchronous timing
3 types of synchronous protocols
SDLC
HDLC
Bisync
Data is transmitted in continuous streams, but w/o an external clock
Isochronous
Places header/trailer to frame to synchronize data flow through a system
Flow control
Speed at which information moves across the media
Signal rate
Time it takes to send a character, including start and stop bits
Character interval
Measurement of the signaling speed of a data transmission device and it equivalent to the maximum # of signaling elements(symbols) sent per second. (Modulation rate)
Baud rate
Measure of throughout or rare of data transfer and represents the # of bits that are transmitted within a second.
Bit rate
Nothing more than counting the # of bits received in a specific time interval(second)
Bit count integrity
Allow users of our nations most important telecommunications services of the national security and emergency preparedness system to receive treatment on a priority basis
Purposes of tsp
Telecommunications service priorities
What are the two parts of the TSP code
TSP Control identifier/TSP Code
Tsp code breakdown
1-9 identifier
10 position is hyphen
11/12 position is tsp code
What is used to assign the priority for provisioning and restoration purposes
TSP code
Communication terms
Circuit
Channel
Trunk
Link
Complete path between two end terminals over which one or two way comm may be provided
Circuit
Local users information accesses a multiplexer
Channel
Multiplexer combines several channels into a serial data stream called a trunk
Trunk
Path that your facility connects to/from the outside world
Link
Who can only negotiate and write contracts for telecommunications services
DITCO
Submitted within 72 hours when all service meets all details of the TSO
In effect
Must notify within 72 hours and submitted for several reasons
Delayed service report
Follow up reports every 30 days are sent…. Services have not met technical parameters require but customer can pass info on it
Exception report
___________ performs function of combining several data or voice communications channels into one composite signal, which can be transmitted between two locations cheaper than the cost of individual lines
Multiplexer
Communication discipline used between two multiplexers
Link protocol
What is the primary reason to multiplex ?
Cost
What are the other 2 reasons besides cost to multiplex ?
Inherent error correction
Inherent security
Achieved by individual data streams are formatted into a single comm line on one end and broke up into individual components on the other end
Inherent security
Takes individual data and transmitting it as data frames, there is an error detection/retransmission scheme built in
Inherent error detection
Combining many signals into one (TX)
Multiplexing
Splitting one signal into many signals (RX)
De multiplex
Dividing the circuit horizontally… Circuit divided into series of separate channels , each transmitting on different frequency
FDM (Frequency decision multiplexing)
Amount of time per slot is variable
Asynchronous TDM
Each signal is given a unique but equal time slot
Synchronous TDM
Initially accomplished by sampling the signal 8000 times each second and using 8 bits to digitally represent the amplitude of the voltage at any point on the analog sine wave
Digitizing
Most widely used system for transmission of TDM digital signals
T-carrier system
Building block for all multiplexed digital data networks
T-1 used in most major trunk circuits
Organizing bits in an orderly manner
Framing
Two types of T-1 framing
D4 super frame
Extended super frame
Extends the d4 superframe from 12 to 24 frames….. Provides enhanced signaling and error testing over D4 framing
Extended superframe
Encoding bits for transportation across T-1 network
Line coding
Alternate between positive and negative pulses for successive 1s
AMI
Two successive positive/negative pulses appear on the line /detects errors
Bipolar violation
Uses bpvs to indicate that the users data contains a long string of zeros
Bipolar 8 zero Substitution (B8ZS)
Clock signal required to send data and maintain synchronization
Synchronous
Transmits data in between a start/stop bit in order to maintain synchronization
Asynchronous transmission
A version of FDM used in fiber-optic cables
Wave division multiplexing
A clock signal required to send data and maintain synchronization
Synchronous transmission
Transmits data in between a start/stop bit in order to maintain synchronization
Asynchronous transmission
A version of FDM used in fiber-optic cables
Wave division multiplexing
Responsible for jointing the signals at the transmitting end
Multiplexer (Mux)
Responsible for splitting the signals at the receiving end
Demultiplexer
In FDM this is the unused portion of circuit that separate the frequencies from each other
Guard bands
What is the aggregate serial data stream found in-between multiplexers
Trunk
The 5th digit on a temporary ccsd is always a
P
Most widely used system for transmission of time division multiplexed digital signals
T carrier system
What is the basic/most common organization scheme
Ds1 frame
How many DS0s does T-1 equal
24
What is the transmission rate for T-1
1.544 Mbps
What is refereed to when digital signals produce 64kbits.. Thus became the standard speed of an individual digital circuit
Ds0 or digital signal level zero
What are the two types of general timing sources
Internal and external
Internal timing sources use?
Crystal oscillators
Crystals absorb and release energy that is used to develop a_______
Timing signal/clock signal
What does most communications equipment contain?
Internal clock/crystal oscillator
________ are extremely precise timekeeping devices that use the natural vibration frequencies of an atomic or molecular system to keep a crystal oscillator locked to a precise frequency.
Atomic clock
The two most widely used atomic clocks in the military are?
Cesium beam
Rubidium
What is the most precise atomic clock?
Cesium beam
A highly accurate space based timing system
GPS
How many operational satellites does the gps consist of and where are they updates from
31 & Schroeder AFB, CO
What is the current time standard for the US
Cesium beam atomic frequency standard
What are divided into stratum levels
Network clocks
What are the stratum levels in order
- GPS, Cesium Beam (most accurate)
- rubidium oscillator (crypto module)
- Promina internal oscillator
- Clock system (least accurate)
What develops it’s timing signal from transitions in a receive data stream
Recovered timing
How many local user circuits does an FCC-100 support ?
16
What are the modules of an FCC-100
Front Panel interface module Processor module Mux/dmux module Aggregate module Port carrier module
What provides the interfaces between the multiplexer and the transmission media going towards the distant end
Aggregate module
Provides the user transmission media interface and cable termination for two local user channels
Port carrier module
Communicatin link between the processor module and either the operators panel or an external control terminal
Front panel interface module
Communicates with all other modules, stores configuration data in nonvolatile memory and uses this data to initialize he system and compute the frame synchronization table
Processor module
This module does multiplexing and dr multiplexing of data between the aggregate and ports
Mux/demux module
Where do you connect the users cable and POWER
Backplane interface
How many connectors does the backplane have
19
A way to redirect data being sent or received
Loop backs
4 types of loop backs
Internal - own data to itself
External - data is from distant end
Local -local FCC 100
Remote -distant fcc100
It’s goal was to be a single network for all traffic such as voice, video, and data
ATM
Method of comm that is used for both LAN and wan technology
ATM
What is the fixed length for an ATM cell ?
53 bytes
What does being fixed in length allow the information to be transported in
A predictable manner
What are the two main parts of the cell
Headed and payload
What are the two headed formats
Uni
Nni
How may bytes is the headed of an ATM cell
5
How many bytes is the payload of an ATM cell
48
What does the header carry ?
Addressing scheme
What does the payload carry
The actual info, voice, data or video
How many layers does the ATM reference model have
3
What are the layers of the ATM reference module
ATM adaptation layer-layer 2
ATM layer-layer 2
Physical layer- layer 1
What defines the electrical characteristics and network interfaces
Physical layer
What takes the data to be sent and attached the header info to the payload, this assuring the cell is sent on the right connection
ATM Layer
This layer assures the appropriate service characteristics and divides all types of data to be inserted into the payload that will make up the ATM cell
ATM adaptation layer (AAL)
What is responsible for cell transit through an ATM newt work
ATM switch
What does all the packet switching between the backbones and are typically connected via T3, ATM or SONET
ATM router
What are two ATM physical connections
Point to point
Point to multi point
What are the two types of ATM Virtual connections
Virtual channel identifier (vci)
Virtual path identifier (vpi)
What are two types of ATM services
PVC permanent virtual circuits
Svc switched virtual circuits
Allows direct connectivity between sites
PVC
______ is created dynamically and remains in use only as long as data is being transferred
SVC
A protocol defined by the ATM forum that gives stations attached via ATM the same capabilities they normally obtain from legacy LANs
LANE
What protocol basic function is to resolve MAC addresses to ATM addresses
LANE
ATM advantages
One network for all traffic Enables new applications Compatibility Incremental migration Simplified network management Long architectural lifetime
ATM disadvantages
Overhead of cell header
Complex mechanism for achieving QOS
Cost
Congestion may cause cell loss
How many physical slots does a promina 200 have?
8
Slot 1 is reserved for?
Redundant PLM
What are the card types
Front cards
Backplane
Read cards
What card contains the logic circuitry for their specific function
Front card
Large circuit card, similar to the motherboard of a computer
Backplane
Provide physical interfaces to devices external to the multiplexed
Rear cards
What are a front and rear card together called ?
Module
Other than the PLM , what do all other modules fall into? 2 categories
Port side or trunk side
What side allows users to access the promina network ?
Port side
What modules provide connectivity to other promina nodes?
Trunk side
What is another type of card you may see that has no rear card or external ports?
Server card
Rear interface card that provides operator access to configure, monitor and diagnose the promina network
PLMI
2 di-group, clear channel interface that suppers the T-1 digital voice interface
PRC
Allows connection up to 4 phones
Converts voice signals from analog to digital and digital to analog
PVA
Multiplexes data from port side modules into a proprietary bundle of DS0s
TRK-3
What is an allocation of bandwidth for sending data in separate directions
Bundle
What requires CSU/DSU and supports symmetric full-duplex and simplex calls in asymmetric trunk mode
SA-TRK
This module provide transmit and receive timing, non transparent signaling, Cts signal following eta with zero delay
HSD-2
User capability to connect DTE/DCE devices to promina network
Max card speed must be greater than fastest port speed
USD
Needed to concert the RS 530 output of our TRK-3 module to a T1 format
CSU/DSU
How many logical shelfs are there
16
How many slots does the promina 400 have
12