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Thursday, May 16, 2019

Which of theses network characteristics is commonly associated with an echo on a VoIP connection?

Which of theses network characteristics is commonly associated with an echo on a VoIP connection?

  • Propagation delay
  • Signal capture and regeneration from link to link
  • Packet queue delay
  • Connection latency 

Which of theses network characteristics is commonly associated with an echo on a VoIP connection?

EXPLANATION

Here are the factors that tend to cause VoIP latency:
  • You lack sufficient bandwidth. When an internet connection is slow, data packets take more time to flow to and fro. This causes quality to suffer. Often, the packets arrive in the wrong order, which makes reassembly impossible unless the order is restored. This is one of the disadvantages of packet switching, which VoIP uses.
  • Your firewall might be blocking traffic. Checkpoints are always a bottleneck, so make sure you allow clearance for your VoIP apps within the firewall software.
  • The wrong codecs are being used. Codecs are programs used to encode voice signals into digital data for transmission over the network, and your provider might be using the wrong one. You can't do anything about that; however, if you're using a VoIP app that allows you to tweak codecs, try changing them.
  • You're using old hardware. Old hardware with new software or new networks might not work that well, and delay and latency are often a result. Try using a different telephone adapter or phone (if you are using an IP phone or any other VoIP-specific hardware). Your hub also might be a culprit. Headsets often cause latency, too.
  • Your system might be converting the signal to or from analog or digital.
  • Buffering is causing audio latency. Buffering occurs when audio data is being transferred and when there's a difference between the time of transmission and reception.
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What circuitry is used in VoIP to convert analog voice to digital signals for transmission, and digital signals to analog voice for playback?

What circuitry is used in VoIP to convert analog voice to digital signals for transmission, and digital signals to analog voice for playback?

  • Digital-to-analog converter (DAC)
  • Audio codec
  • Digital signal processor (DSP)
  • Analog-to-digital converter (ADC) 
What circuitry is used in VoIP to convert analog voice to digital signals for transmission, and digital signals to analog voice for playback?

EXPLANATION

 

Analog-to-Digital (ATD) Converter

Prior to digital technology, electronic transmission was limited to analog technology, which conveys data as electronic signals of varying frequency or amplitude that are added to carrier waves of a given frequency. Broadcast and phone transmission has conventionally used analog technology.
Digital technology is primarily used with new physical communications media, such as satellite and fiber optic transmissions. One example of an Analog-to-Digital converter is a modem, which is used to convert the digital information in your computer to analog signals for your phone line; converting analog phone signals to digital information for your computer.
When you record your voice or use a VoIP solution on your computer, you are using an analog-to-digital technology to convert those vocal inputs (analog) into a digital form. An analog signal can be represented as a series of sine waves. The term originated because the modulation of the carrier wave is analogous to the fluctuations of the human voice or other sound that is being transmitted. The term analog, also describes any fluctuating, evolving, or continually changing process. Any signals in the “real world” such as light, sound, etc. can be considered analog.
Digital signals propagate more efficiently than analog signals, largely because digital impulses, which are well-defined and orderly, are easier for electronic circuits to distinguish from noise, which is chaotic. This is the chief advantage of digital modes in communications. Computers “talk” and “think” in terms of binary digital data, creating the need for ATD converters. In other words, analog signals must be turned back into digital form (demodulated) at the receiving end so that the computer may process this data in it’s digital format.
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What unit is used to measure the width of the smallest wire on a computer chip?

What unit is used to measure the width of the smallest wire on a computer chip?

  • Millimeters
  • Angstroms
  • Microns
  • Hexadecimal 
What unit is used to measure the width of the smallest wire on a computer chip?

EXPLANATION

The smallest wire on a chip is measured in microns. Current chips have wires that are less than one micron wide, while a human hair is about 100 microns thick.  

 The smallest physical units in my computer are the electron holes in the P-N junctions of the semiconductors: they are so small that they are not even there: it's just an imbalance in the electromagnetic force. If that's not quite the answer you're looking for, then you can go with the diode on the VLSI chip that contains that P-N junction.



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Which of these is not a type of motherboard expansion slot?

Which of these is not a type of motherboard expansion slot?

  • PCI
  • ISA
  • AGP
  • ATX 
Which of these is not a type of motherboard expansion slot?

EXPLANATION

 
ATX is a motherboard configuration specification developed by Intel in 1995 to improve on previous de facto standards like the AT design. It was the first major change in desktop computer enclosure, motherboard and power supply design in many years, improving standardization and interchangeability of parts.

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How can you tell that a ribbon cable should only be used to connect a floppy drive?

How can you tell that a ribbon cable should only be used to connect a floppy drive?

  • It has a red line
  • It is rainbow colored
  • It is white
  • It has a twist in it 
How can you tell that a ribbon cable should only be used to connect a floppy drive?

EXPLANATION

 The connectors on the ends of the cable are a different size than the connectors for a standard IDE device like a Hard Drive or CD rom. You should also notice that there is a twist in the cable between two of the connectors. 

There are two cables that connect to the floppy drive in a desktop computer.

  • There is a four pin power cable
  • There is a ribbon cable that has a part twisted end (the twisted end connects to the floppy drive).

 


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What is the name of the type of cable that contains many conducting wires running in the same flat plane?

What is the name of the type of cable that contains many conducting wires running in the same flat plane?

  • Optical cable
  • Flat cable
  • Ribbon cable
  • Patch cable 
What is the name of the type of cable that contains many conducting wires running in the same flat plane?


EXPLANATION

A ribbon cable (also known as multi-wire planar cable) is a cable with many conducting wires running parallel to each other on the same flat plane. As a result the cable is wide and flat.

A ribbon cable (also known as multi-wire planar cable) is a cable with many conducting wires running parallel to each other on the same flat plane. As a result the cable is wide and flat. Its name comes from its resemblance to a piece of ribbon.[1]
Ribbon cables are usually seen for internal peripherals in computers, such as hard drives, CD drives and floppy drives. On some older computer systems (such as the BBC Micro and Apple II series) they were used for external connections as well. The ribbon-like shape interferes with computer cooling by disrupting airflow within the case and also makes the cables awkward to handle, especially when there are a lot of them; as a result, round cables have almost entirely replaced ribbon cables for external connections and are increasingly being used internally as well.

 
 

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What IRQ does the system timer commonly use?

What IRQ does the system timer commonly use?

  • 1
  • 10
  • 13
What IRQ does the system timer commonly use?

EXPLANATION

IRQ 0 - System timer. IRQ 1 - Keyboard. IRQ 2 - Cascaded signals from IRQs 8-15. IRQ 3 - COM2 (Default) and COM4 (User) serial ports
IRQ 4 - COM1 (Default) and COM3 (User) serial ports
IRQ 5 - LPT2 Parallel Port 2 or sound card
IRQ 6 - Floppy disk controller
IRQ 7 - LPT1 Parallel Port 1 or sound card (8-bit Sound Blaster and compatibles) IRQ 8 - Real time clock
IRQ 9 - Free / Open interrupt / Available / SCSI. Any devices configured to use IRQ 2 will actually be using IRQ 9.
IRQ 10 - Free
IRQ 11 - Free IRQ 12 - PS/2 connector Mouse. IRQ 13 - ISA / Math Co-Processor
IRQ 14 - Primary IDE. If no Primary IDE this can be changed
IRQ 15 - Secondary IDE These are just a set of standard IRQs. For much more detail check our Ralf Brown's list located at http://www.cs.cmu.edu/~ralf/files.html


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