minami

Reliable links

  1. TCP Overview

    • Transport-layer protocol built on IP
    • Provides reliable, ordered byte stream
    • Prevents gaps, duplication, corruption
    • Implements stability patterns

  2. Reliability Mechanisms

    • Data stream split into numbered segments
    • Requires acknowledgment for each segment
    • Uses timers for retransmission
    • Checksums verify data integrity

  3. Connection States

    • Opening (connection creation)
    • Established (data transfer)
    • Closing (connection termination)

  4. Three-Way Handshake

    • Requires full round-trip before data transfer
    • Uses sequence numbers for ordering

  5. Flow Control

    • Prevents sender overwhelming receiver
    • Uses receive buffer for incoming data
    • Receiver communicates buffer size in ACKs
    • Similar to connection-level rate-limiting

  6. Congestion Control

    • sender maintains a so-called congestion window which represents the total number of outstanding segments that can be sent without an acknowledgment from the other side
    • Prevents network flooding
    • Uses congestion window for in-flight data
    • Window size grows exponentially initially
    • Reduces on packet loss (segment is lost), this mechanism is called congestion avoidance
    • Bandwidth = Window Size / RTT

  7. UDP Alternative

    • Connectionless, unreliable protocol
    • No guaranteed delivery or ordering
    • No flow/congestion control
    • Useful for real-time applications (e.g. games)
    • Better for cases where speed > reliability

Key Performance Factors: