Link Layer and Slotted ALOHA Quizzes

Flow control = Pacing between adjacent sending and receiving nodes Error detection = Detects errors caused by signal attenuation and noise Error correction = Identifies and corrects bit errors without retransmission Full-duplex = Both nodes can transmit simultaneously

Adaptor = Network interface card (NIC) Ethernet card = Used for wired local area networks 802.11 card = Used for wireless local area networks Bus = Interconnects components within the host system

Sending side = Encapsulates datagram in a frame Receiving side = Looks for errors and performs flow control Datagram = The main unit of data being transmitted Frame = The encapsulation of datagram for transmission

<p>Low bit-error link = Seldom used for unreliable delivery Wireless links = Often have high error rates Half-duplex = Nodes can transmit, but not simultaneously End-to-end reliability = Ensures data integrity across the entire transmission path</p> Signup and view all the answers

<p>Retransmission = Signals sender to resend corrupted data Error checking bits = Added to frames for detecting errors Flow control = Regulates data transmission rate Bit error correction = Corrects errors without needing a retransmission</p> Signup and view all the answers

<p>Parity Checking = Detect single bit errors or correct single bit errors Internet Checksum = Detect errors in transmitted packets by computing a checksum Cyclic Redundancy Check = Detect errors using a generator and checking for divisibility Error Detection and Correction (EDC) = Add redundancy to protect data from errors</p> Signup and view all the answers

<p>ARP = Address Resolution Protocol for mapping IP addresses to MAC addresses Ethernet = Protocol for LAN communication using frames MPLS = Multiprotocol Label Switching for efficient data forwarding VLANs = Virtual Local Area Networks for segmenting network traffic</p> Signup and view all the answers

<p>Single Bit Parity = Detects single bit errors only Two-Dimensional Bit Parity = Detects and corrects single bit errors 16-bit Integer Checksum = Sum of segment contents for error detection Cyclic Redundancy Check = Uses division by a generator to detect errors</p> Signup and view all the answers

<p>Error Detection = Identify and potentially correct errors in data transmission Multiple Access Protocols = Manage how multiple devices access the same network medium Data Center Networking = Facilitate communication within and between data centers Link Virtualization = Abstract physical links to optimize network performance</p> Signup and view all the answers

<p>Sender = Computes checksum before transmission Receiver = Checks received data against checksum Data Field = Contains actual transmitted information Checksum Field = Holds the computed checksum for validation</p> Signup and view all the answers

<p>Slotted ALOHA = Synchronized transmission slots ALOHA = Uncoordinated transmission CSMA/CD = Collision detection CSMA/CA = Collision avoidance</p> Signup and view all the answers

<p>Single active node = Continuous transmission at full channel rate Highly decentralized = Only synchronization needed is for slots Simple = Easier implementation Efficient under load = Max efficiency at 1/e</p> Signup and view all the answers

<p>Collision = Two or more nodes transmitting simultaneously Retransmission = Sending a frame again after a collision Synchronization = Coordinating time slots for transmission Idle slots = Time periods without successful transmissions</p> Signup and view all the answers

<p>Time slots = Equal size for frame transmission Frame size = All frames are the same size Probability p = Transmission probability for nodes Collision detection = Nodes detect collision in the slot</p> Signup and view all the answers

<p>Idle slots = Wasted time due to no transmissions Successful transmission = Slot utilized without collision Busy slots = Slots with ongoing transmissions Collisions = Result in retransmission delays</p> Signup and view all the answers

<p>Decentralized nature = No central coordination required Collision detection = All nodes can sense if a collision occurs Synchronized nodes = Necessary for time slot alignment Probability mechanism = Allows for variable retransmission attempts</p> Signup and view all the answers

<p>Collisions = Lead to wasted transmission slots Clock synchronization = Requires accurate timing across nodes Transmission attempts = Dependent on node's probability p for activation Infinite nodes = Can affect maximum efficiency calculations</p> Signup and view all the answers

<p>Max efficiency = Achieved at $1/e$ Probability $p$ = Transmits in slot with this probability Successful slots = Fraction of slots with successful transmissions Limit process = Analyzing behavior as $N$ approaches infinity</p> Signup and view all the answers

<p>Pure ALOHA = Transmits immediately when a frame arrives without synchronization CSMA = Listens before transmitting and defers if the channel is busy CSMA/CD = Detects collisions and aborts transmission to reduce wastage Slotted ALOHA = Uses synchronization for transmitting frames and reducing collisions</p> Signup and view all the answers

<p>P(success by given node) = $p(1-p)^{2(N-1)}$ Collision probability in unslotted ALOHA = $P(node transmits) imes P(no other node transmits)$ Optimum success in ALOHA = $rac{1}{2e}$ Successful transmission probability = $p(1-p)^{N-1}$</p> Signup and view all the answers

<p>Pure ALOHA = Higher collision probability due to no synchronization CSMA = Defers transmission if the channel is busy CSMA/CD = Aborts transmission upon detecting collisions Slotted ALOHA = Lower collision probability compared to Pure ALOHA</p> Signup and view all the answers

<p>Carrier Sensing = Listen before transmit in CSMA Collision Detection = Measure signal strength in CSMA/CD Immediate Transmission = Characteristic of Pure ALOHA Deferred Transmission = Characteristic of CSMA protocol</p> Signup and view all the answers

<p>Wireless LANs = Difficult collision detection Wired LANs = Easy to measure signal strengths Unslotted ALOHA = Frames collide if sent in overlapping time slots CSMA = Prevents interruption during active transmission</p> Signup and view all the answers

<p>Propagation Delay = Time taken for a signal to travel from sender to receiver Channel Idle = State when no transmission is occurring Collision = When two frames are sent simultaneously leading to interference Frame Transmission Time = Time it takes to send an entire data frame</p> Signup and view all the answers

<p>Pure ALOHA = 18% efficiency Slotted ALOHA = More efficient than Pure ALOHA CSMA = Generally has better efficiency than ALOHA CSMA/CD = Improves efficiency by reducing collision losses</p> Signup and view all the answers