Understanding Link Layer Networks: Protocols, Components, and Configurations

Posted on Feb 21, 2025 in Computers

Chapter 9: Link Layer Networks

  1. What is the role and responsibility of the Level 2 Link Layer Network?
  2. What are the components addressed by the link layer so that it develops its responsibilities?
  3. What are the 3 types of configuration that a link can be implemented?
  4. What are the differences between the IP address and MAC address (Media Access Control)?
  5. In which part of the network protocol is Ethernet used?
  6. What were the reasons for the success of the Ethernet protocol compared to its competitors: Token Ring, FDDI, and ATM?
  7. What is CSMA/CD?
  8. Describe the operation of the access method CSMA/CD.
  9. What is a SWITCH? What is the principle of its operation?
  10. Describe how the switch performs the process of self-learning.
  11. What is the difference between network devices Switch and Router?
  12. Where is the protocol PPP (Point to Point Protocol) used?
  13. What are the characteristics of PPP?
  14. What are the stages of communication protocol PPP? Briefly describe each one.

Chapter 10: Physical Layer and Media

  1. At the physical layer, what are 3 ways to use the media? What is the difference in operation between them?
  2. What are the types of signals that broadcast media can be used to allow communication?
  3. Describe what a coaxial cable is: physical characteristics, usage, technology, etc.
  4. Describe what a fiber optic cable is, including its physical characteristics, performance (error rate), influence of electromagnetic fields, type of material used, technologies, etc.

Answers

  1. Download datagrams between adjacent nodes through the link.
  2. Hosts, routers, and communication channels.
  3. Point-to-point, broadcast, and switched.
  4. The IP address is a network layer address handled by the router and used to take the datagram to the destination IP subnet. The MAC address is programmed into the network adapter and is used to carry datagrams between interfaces connected physically on the same LAN.
  5. The link layer.
  6. It’s cheap, fast, and functional.
  7. Multiple access with carrier detection and collision.
  8. Transmission starts only if the network segment is free. The transmitter monitors the circuit and, if it detects a collision, stops transmitting, sends a signal reinforcement crash, and restarts transmission after a random period.
  9. A switch is a link layer device that divides LANs, filters packets, and creates segments in separate collision domains. Its principle of functioning is learning the way by which hosts can be achieved.
  10. Learning the way (interfaces) through which hosts can be achieved by analyzing the source MAC address of Ethernet packets.
  11. Routers are devices on the network layer, maintain routing tables, and implement routing algorithms. Switches are link layer devices, keep switching tables, and implement filtering using learning algorithms.
  12. Used to link access networks simpler (IP, X.25, ATM).
  13. It is the link layer, directly connects two hosts in a peer-to-point manner, and can carry different network protocols.
    • Connection inactive: Link ready for dispatch of the transmission (the beginning and end of a connection).
    • Making the connection: Exchange of LCP packets.
    • Authentication: Exchange username and password (optional).
    • Negotiation of parameters: For each protocol transported, transport parameters are defined.
  15. They are simplex, half-duplex, and full-duplex: the difference is in the direction of transmission.
  16. Radio waves, light, and electrical signals.
  17. A coaxial cable is a cable with two concentric copper conductors and two-way communication. Used in broadband (cable with multiple channels) and baseband (single sign data each time).
  18. A fiber optic cable is a cable that carries pulses of light, has a low error rate, and repeaters spaced far apart. It is immune to electromagnetic interference, has low volume and weight, and uses LEDs/lasers as light sources. Can be made of silica or plastic, and your wires may be of types: multimode step, gradual, and multimode fibers.