Term
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Definition
n Each DS-0 is called a time slot
n 8000 frames/sec * 8 bits/slot = 64 Kbps
n 24 * 8 (bits/slot) + 1 = 193 bits/frame
n 8000 Framing bits sent per second
n 8000 frames/sec * 193 bits/frame = 1.544 Mbps
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Term
| Half-Duplex Communication |
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Definition
A half duplex connection transmits data in both directions but in only one direction at a time. Example: e-mail, CB radios (circa 1970s). |
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Term
| How high up are LEO satellites and how many are needed to cover the earth? |
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Definition
| Low Earth Orbit - 100 miles to 1000 miles (above Earth). Requires 48-56 satellites to provide full Earth coverage. |
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Term
| Do Parity Checks catch all transmission errors? |
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Definition
Cyclic Redundancy Checksum catches most error transmissions while Simple and Longitudinal parity checks only catch specific types of errors. So no, not all errors can be caught by parity checks. |
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Term
What is more efficient? Synchronous or Asynchronous connections |
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Definition
A synchronous connection is more elaborate but transfers data in a more efficient manner. Asynchronous transmission is inefficient (about 20% of the bits are overhead – Start/Stop frames) |
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Term
What is roll call polling? |
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Definition
| The mainframe polls (checking the terminal to see if it has information to send to the mainframe) each terminal in a round-robin (daisy chain) fashion. |
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Term
Terminal to Mainframe connections |
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Definition
| These connections can either have point-to-point connection which is a direct, unshared (“dedicated”) connection between a terminal and a mainframe computer or a multipoint connection which is a shared connection between multiple terminals and a mainframe computer. |
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Term
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Definition
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Term
| What is the most popular and prevalent LAN topology? |
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Definition
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Term
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Definition
Jitter is the deviation in or displacement of some aspect of the pulses in a high-frequency digital signal. As the name suggests, jitter can be thought of as shaky pulses. |
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Term
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Definition
| Connects a LAN to another LAN using the same protocol |
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Term
| What is the second name given to the Network Layer of the OSI Model? |
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Definition
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Term
| What is the key differentiator for 2G cellular service? |
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Definition
Start of all digital service |
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Term
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Definition
Special set of rules that end points in a network connection use when they communicate. |
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Term
| What is the difference between Frequency Division Multiplexing (FDM) and Time Division Multiplexing (TDM)? |
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Definition
| FDM is assignment of non-overlapping frequency ranges to each “user” or signal on a medium while TDM is sharing of the signal is accomplished by dividing available transmission time on a (transmission) medium among many users. |
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Term
| What is the difference between logical and physical connections? |
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Definition
Logical connections exist in Software and Physical connections exist in hardware and cables |
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Term
Which Department of US Govt developed the TCP/IP protocol suite? |
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Definition
U.S. Department of Defense (DARPANET) |
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Term
Are Token Ring Topologies popular? |
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Definition
| NO, these topologies are pratically extinct |
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Term
Are the vast majority of signals transmitted in networks analog or digital? |
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Definition
| Digital signals are mostly transmitted over networks today |
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Term
| Is digital considered to be 1s and 0s? |
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Definition
| No, this is considered to be binary code. |
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Term
| What standard is CSMA/CD known as? |
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Definition
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Term
| What is more efficient? Synchronous TDM or Statistical TDM |
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Definition
| Statistical Time Division Multiplexing as it offers a more efficient use of bandwidth |
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Term
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Definition
| Continuous loss of a signal’s strength as it travels through a medium |
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Term
| Is the DSN signal system (DS-1s and DS-3)hierarchical? |
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Definition
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Term
| Is Instant Messaging a form of peer to peer communication/networking? |
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Definition
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Term
What transmission media requires line of sight? |
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Definition
Licensed and Unlicensed Microwave Antennas |
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Term
What is a parity check and what does it do? |
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Definition
| A technique of checking whether data has been lost or written over when it's transmitted between computers |
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Term
What three things can receivers do for error control? |
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Definition
Do nothing (discard the data), return an error message to the transmitter, fix the error with no further help from the transmitter |
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Term
What is the basic definition of Bluetooth technology? |
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Definition
| A radio frequency specification for short-range, point-to-multipoint voice and data transfer. Typical link range is from 10 centimeters to 10 meters, but can be extended to 100 meters by increasing the power levels. |
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Term
| What networking device is needed to make a LAN to WAN connection? |
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Definition
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Term
| What is connection negotiation in regards to modems? |
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Definition
| Ability of a modem to automatically fall forward or fall back to faster or slower speeds, respectively. |
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Term
| What does a regenerator do? |
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Definition
| Regenerates signal to comepensate for weakening of signal traveling through medium (attenuation) |
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Term
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Definition
| The number of times a signal makes a complete cycle within a given time frame. |
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Term
How does Pulse Code Modulation work? |
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Definition
The analog waveform is sampled at specific intervals and the “snapshots” are converted to binary values |
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Term
| What 3 ways can be used to convert digital data into analog signals? |
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Definition
| 3 types of modulation can be used: Frequency, Phase and Amplitude |
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Term
| What dual capabilities does a channel bank possess? |
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Definition
| Acts as a multiplexor and an analog-to-digital conversion device |
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Term
What does White Noise (Gaussian Noise) do to a signal? |
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Definition
It’s relatively constant and can be reduced but if too strong can completely disrupt signal |
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Term
What is the sliding window protocol and what does it do? |
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Definition
| A technique, also known as windowing, is used by the Internet's Transmission Control Protocol (TCP) as a method of controlling the flow of packets between two computers. TCP requires that all transmitted data be acknowledged by the receiving host. It is a method by which multiple packets of data can be affirmed with a single acknowledgment. |
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Term
| What are the basics of OSI Model Layers 1 and 2 |
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Definition
Layer 1 – Physical Layer - Defines hardware specs such as Transmission Rate, Bit encoding method and Cable types. Responsible for establishing, maintaining, and terminating physical connections between communicating devices.
Layer 2 – Data Link Layer - Responsible for taking the data and transforming it into a frame with header, control and address information, and error detection code. Sets up communications link between hardware devices.
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Term
Which OSI Layer was broken into 2 sublayers and what are those layers? |
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Definition
Data Link Layer and the sublayers are Logical link control (LLC) sub layer and Medium access control (MAC) sub layer |
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Term
| What are the 3 concepts that make cellular technology work? |
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Definition
Frequency Reuse, Frequency Agility, and Call Handoff |
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Term
| How does an Ethernet switch work? |
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Definition
On an Ethernet local area network (LAN), this device determines - from the physical device (Media Access Control or MAC) address in each incoming message frame - which output port to forward it to and out of. |
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Term
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Definition
| The Source Address - identifies the hardware number hardcoded into the NIC (Network Interface Card) of your workstation. It can also be known as the “serial number” for your workstation on the network. |
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Term
| What are the 4 components that make up interface standards? |
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Definition
| Functional, Procedural, Mechanical, and Electrical |
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Term
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Definition
| A standard description or "reference model" for how messages should be transmitted between any two points in a telecommunication network. |
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Term
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Definition
| In programming, a port (noun) is a "logical connection place" and specifically, using the Internet's protocol, TCP/IP, the way a client program specifies a particular server program on a computer in a network. |
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Term
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Definition
| A device or, in some cases, software in a computer, that determines the next network point to which a packet should be forwarded toward its destination. It is connected to at least two networks. |
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