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.
What makes up the first six hex digits of a MAC address?
Organizationally Unique Identifier (OUI)
Where is fiber optic cabling used?
- enterprise networks for connection infrastructures together
- Fiber-to-the-Home provides always on broadband serves to homes and small businesses
- Long haul network runs
- Submarine cable
What is a hextet?
A segment of 16 bits or four hex values
How do cables combat interference? (three answers)
Wrapped in shielding and has to be grounded. Opposite cables are wrapped around.
What does CSMA/CD and CMSA/CA mean?
- Carrier Sense Multiple Access/Collision Detection
- Carrier Sense Multiple Access/Collision Avoidance
What are the fiber connectors, what does their names mean?
- ST = Straight Tip
- SC = Subscriber or Square
- LC = Lucent
What is encoding?
A method of converting a stream of data bits into a predefined code to provide a predictable pattern to help distinguish data bits from control bits
What are the pros and cons to copper cabling?
Pros: inexpensive, easy to install, low electrical resistance
Cons: max distance, signal interference
What is fiber optic?
Cables that uses a strand of glass to send encoded data with light
What are some WAN protocols?
- Point-to-Point Protocol (PPP)
- High-Level Data Link Control (HDLC)
- Frame Relay
- Asynchronous Transfer Mode (ATM)
- X.25
What are the three interferences and describe them?
- Signal attenuation from long distance runs
- Electromagnetic interference and radio frequency interference distort and corrupts the data signals.
- Cross talk is a disturbance caused by the electric or magnetic fields of a signal on one wire to another.
What does the router do when it receives a frame?
- Accepts the frame
- Decapsulates the frame
- Encapsulates the packet into a new frame
- Forwards the new frame to the appropriate medium
What are the organizations that form the standards for the data link layer?
- The Institute of Electrical and Electronics Engineers (IEEE)
- International Telecom Union (ITU)
- International Organization for Standardization (ISO)
American National Standards Institute (ANSI)
How many bits are in an IPv4 address?
32 bits
What are the tree common wireless technologies and what are their IEEE standard number?
- WiFi (802.11)
- Bluetooth (802.15)
- ZigBee (802.15.4)
What is the standard color pattern for ethernet? What are the standards name?
TIA-568A - Gw/G/Ow/B/Bw/O/Brw/Br
TIA-568B - Ow/O/Gw/B/Bw/G/Brw/Br
What are the coaxial connectors?
- Bayonet Neill-Concelman (BNC) is used for analog video
- F Type is used to cable television
- N Type is for low frequency applications
What are the three types of UDP cable?
- Straight through = the same standard on both sides
- Crossover = A to B or B to A
- Rollover = B to B that is flipped
How long is a standard MAC address in bits?
48 bits
What does C represent in hex?
12
Convert 42 into binary
00101010
What does 9 represent in binary?
9 duh
Convert 235 into binary
EB
Convert 17 into hex
11
Convert 165 to hex
A5
Convert 201 to binary
11001001
Convert F7 to decimal
247
Convert 62 to decimal
98
Convert A3 to decimal
163c
Convert 77 to binary
1001101
What does E represent in hex?
14
What does A represent in hex?
10
