Fichas
Physical Layer 2
Fichas del conjunto (25)
- 1What is the lowest layer in the ISO OSI model?Physical
- 2What are the 3 classes of signalling ability that the Physical layer has?- Simplex: Single direction comm.
- Half-Duplex: Send or receive at any 1 time
- Full-Duplex: Send and receive at any 1 time - 3What are the 2 main types of transmission media?- Wired (Guided)
- Wireless (Unguided) - 4Name 3 different types of cable and their main purpose- Coaxial Cable: TV/Internet
- Twisted Pair: Can run for kilometres without amplification
- Optical Fibre: Ideal for high speed, long distance comm. - 5What does PLC stand for and what does it allow?PowerLine Communication
- Allows data transfer over existing infrastructure
- Can cause significant radio interference
- Higher transmission rate = lower distance
- Insecure - 6Name 3 different forms of wireless transmission media- Wireless Data Communication (WiFi)
- Bluetooth
- Near Field Communication (NFC) - 7Name all data communication equipment that are part of the communications path- Hubs
- Repeaters
- Bridges
- Switches
- Routers
- Gateways - 8What do hubs do?- Connect 2 cables together
- Doesn't interact w/ signal - 9What do repeaters do?Regenerates a signal
- Requires a power supply - 10What do bridges do?- Checks physical (MAC) address contained within the frame
- Can filter traffic - 11What do Routers do?- Routes packets based on logical addresses
- Used to connect LANs and WANs to the internet
- Uses routing table to make decisions about route - 12What do switches do?- Similar to bride, routing based on frame address
- 13What is a gateway?- Interface between networks that potentially use different protocols
- Operates at any later - 14What are the 2 different types of Network topologies?- Physical
- Logical - 15Physical Topologies- Relate to layout of network, arrangement of devices and how they communicate with each other
- 16Logical Topologies- How the data is actually transferred in a network, how devices are actually connected (i.e. the connected cables)
- 17Examples of Physical Topologies- Ring
- Fully Connected
- Line
- Star
- Mesh
- Tree
- Bus - 18Name the different types of networks- Local Area Network (LAN): Nodes connected in same physical location
- Metropolitan Area Network (MAN): Large network that spans over a metropolitan area
- Campus Area Network (CAN): Large net. linking LANs spanning a campus, corporate or military site
- Wide Area Network (WAN): Covers broad area providing comm. across metropol. regional and national boundaries - 19What is a broadcast network?A network where the transmission medium (Wired/Wireless) is shared between all devices
AKA Multiple Access Networks - 20+/- of broadcast networks+ No routing required
+ Simple addressing system
+ Cost effective
- Not scalable
- Requires some access control - 21Name the different types of access control- Signal Propagation
- Collisions - 22What is signal propagation?The behaviour of a signal when it is transmitted (propagated) from a source to a destination
- 23What is velocity of propagation?Velocity at which a signal propagates from one point to another as a coefficient to the speed of light
- 24What is a collision?When stations transmit at the same time
- 25What are the 2 main types of collision avoidance?- Random Access: Transmit at any time but do something to sense when a collision has occurred and retransmit
- Scheduled Access: Each device takes a turn