Chapter 4: Network Access Flashcards
What is Synchronous signaling?
Synchronous transmissions are synchronized by an external clock
What is asynchronous signalling?
asynchronous transmissions are synchronized by special signals along the transmission medium
What is Bandwidth?
4.1.3.2
bandwidth measures the amount of data that can flow from one place to another in a given amount of time.
What is Throughput?
4.1.3.2
Throughput is the measure of the transfer of bits across the media over a given period of time.
What is good put?
4.1.3.2
Goodput is the measure of usable data transferred over a given period of time
What is EMI?
Electromagnetic Interference
What is RFI?
Radio Frequency Interference
What causes Electromagnetic Interference?
disturbance that affects an electrical circuit due to either electromagnetic induction
What causes Radio Frequency Interference
or electromagnetic radiation emitted from an external source.
What is crosstalk?
4.2.1.1
Crosstalk is a disturbance caused by the electric or magnetic fields of a signal on one wire to the signal in an adjacent wire.
How do stop crosstalk?
Twisted-pair cable, shielded cable, and keeping cables further apart help prevent crosstalk
What is the difference between Copper and fiber cables?
Copper cables are cheaper to run, easy to handle and install, but can not exceed more than a 100m before signal degrades.
Fiber cables a very expensive, have better signals, can carry data over very long distances. Very hard to install and configure.
What is wireless media?
4.2.4.1
Wireless media carry electromagnetic signals that represent the binary digits of data communications using radio or microwave frequencies.
What is the IEEE No. for 5GHz Wireless Media speeds of up to 54 Mb/s?
4.2.4.4
IEEE 802.11a speeds of up to 54 Mb/s
What is the IEEE No. for 2.4GHz Wireless Media with a speeds of up to 11 Mb/s?
4.2.4.4
IEEE 802.11b speeds of up to 11 Mb/s
What is the IEEE No. for 2.4GHz Wireless Media with a speeds of up to 54 Mb/s?
4.2.4.4
IEEE 802.11g speeds of up to 54 Mb/s
What is straight through and where do you use it?
Straight-through cable is used to connect computers and other end-user devices (e.g., printers) to networking devices such as hubs and switches
What is crossover cable and where do you use it?
the wires on the cable are crossed over so that the receive signal pins on the RJ-45 connector.
Its purpose is to allow the direct connection of two LAN devices, such as two hubs, two switches or a hub and a switch. It can also be used to create a direct connection between two computers.
What is a roll over cable and where do you use it?
A flat blue cable used to connect a computer terminal to a router’s console port
What is Single-Mode fiber cable (SMF)?
4.2.3.3
Consists of a very small core and uses expensive laser technology to send a single ray of light. Popular in long-distance situations spanning hundreds of kilometers such as required in long haul telephony and cable TV applications.
What is Multi-Mode fiber cable (SMF)?
4.2.3.3
Consists of a very small core and uses expensive laser technology to send a single ray of light. Popular in long-distance situations spanning hundreds of kilometers such as required in long haul telephony and cable TV applications.
What is a Physical Topologies?
4.4.1.2
physical connections and identifies how end devices and infrastructure devices such as routers, switches, and wireless access points are interconnected. Physical topologies are usually point-to-point or star
What is a logical Topologies?
4.4.1.2
This arrangement consists of virtual connections between the nodes of a network. These logical signal paths are defined by data link layer protocols
What is a Point-to-Point connection Topology?
4.4.2.1
permanent link between two endpoints. For this reason, this is a very popular
What is Hub and Spoke Topology?
4.4.2.1
A WAN version of the star topology in which a central site interconnects branch sites using point-to-point links.
What is a star Topology?
4.4.3.1
End devices are connected to a central intermediate device
What is a bus Topology?
4.4.3.1
All end systems are chained to each other and terminated in some form on each end
What is a ring Topology?
4.4.3.1
End systems are connected to their respective neighbor forming a ring.
What is Half Duplex communication?
4.4.2.4
Both devices can both transmit and receive on the media but cannot do so simultaneously.
What is Full Duplex communication?
4.4.2.4
Both devices can transmit and receive on the media at the same time.
What is Carrier Sense Multiple Access (CSMA) ?
4.4.3.3
When the device attempting to transmit sees that the media is busy, it will wait and try again after a short time period.
What is Carrier sense multiple access with collision detection (CSMA/CD)
4.4.3.3
If signals are then detected that show another device was transmitting at the same time, all devices stop sending and try again later
What is Carrier sense multiple access with collision avoidance (CSMA/CA)
4.4.3.3
The end device examines the media for the presence of a data signal. If the media is free, the device sends a notification across the media of its intent to use it. Once it receives a clearance to transmit, the device then sends the data.
What is the logical link control (LLC)?
The Ethernet LLC sublayer handles the communication between the upper layers and the lower layers. This is typically between the networking software and the device hardware
What is the media access control (MAC)
The MAC sublayer provides addressing and channel access control mechanisms that make it possible for several terminals or network nodes to communicate
