Chapter 2 Flashcards
What does UTP and STP mean?
Unshielded Twisted Pair and Shielded Twisted Pair
What are the pros and cons to wireless connections?
Cons: susceptible to radio and electrical interference and it is slower
Pros: Easy to connect and portable
What does the data link layer do?
- enables upper layer access to the media
- accepts data, usually layer 3 packets, and convers them into layer 2 frames
- Controls how data is receives and placed on the medium
- Receives layer 3 packets and directs them to upper layers
- Performs error detection and rejects data
What is signaling?
The generation of electrical, optical, or wireless signals that represent the 1s and 0s on the media
What are the pros and cons to fiber?
Pro: not affected by EMI, up to 100,000m long, and up to 100gbps speeds
Cons: fragile, expensive connectors, requires installation skills and safety precautions
What are the two data link layer sub layers?
Link Layer Control (LLC) and Media Access Control (MAC)
List the measures of bandwidth, from greatest to least?
Bandwidth (could carry)
Throughput (carries with overhead)
Goodput (actually carries)
What are the WAN typologies?
Point-to-point, hub-and-spoke, and mesh
What is the LLC sublayer?
The logical link control is communicated between the networking software at the other layers. It places the data in the frames based on the protocol for that frame. This info allows multiple layer 3 protocols such as IPv4 and IPv6 to uses the same network interface and media. The LLC sublayer adds Layer 2 control info to help deliver the packets to the destination node.
What is half- and full-duplex?
Half-duplex allows both devices to transmit and receive on the media but cannon at the same time. Full-duplex allows both devices to simultaneously transmit or receive on the shared media.
What is the logical typology?
Refers to the way a network transfers frames from one node to the next.
What does the store-and-forward do?
Receives the entire frame and computes the CRC. If valid, it is sent to the destination. If invalid, it is dropped.
What does cut-through switching do?
If forwards the entire frame before it is entirely received.
Describe how a switch works?
When receiving outside frames, the switch will compare the MAC address in the frame header with the addresses it has in its MAC address table. Once a match has been found, the frame is sent to the port. If none was found, it is broadcasted to all the ports except the one it came from
What is the MAC sublayer?
The Media Access Control sublayer is responsible for data encapsulation and media access control. It provides data ln layer addressing and integrated with various physical layer technologies. The MAC sublayer controls the NIC and other hardware that is responsible for sending and receiving data on the wired or wireless LAN/WAN medium.
What types of memory does a switch have?
Port based memory and shared memory deposits
List and describe the two variants of cut-through switching
- Fast forward: lowest levels of latency by immediately forwarding eh port to the destination address. They may be errors that are sent.
-Fragment-free: stores the first 64 bytes of the frame before forwarding, where a majority of the errors occur.
What are some of the data link layer protocols?
- Ethernet
- 802.11 wireless
- Point-to-point Protocol (PPP)
- High-Level Data Link Control (HDLC)
- Frame Relay
What does the physical layer do?
Describes the standards and physical attributes of the medium you use to connect to a network?
What is the primary purpose of the data link layer in the OSI model?
The primary purpose of the data link layer is to provide reliable point-to-point and point-to-multipoint communication by framing data into frames and detecting errors during transmission.
What is a physical toplogy?
Identifies the physical connection and how the devices and intermediary devices are interconnected.
