Michael Data

OSI Layers

Based on the [http://en.wikipedia.org/wiki/OSI_model OSI standards model].

  • * Application
  • * Presentation
  • * Session
  • * Transport
  • End-to-end control
  • TCP and UDP
  • * Network
  • * Data Link
  • * Physical
  • bit-level operations

Transport Layer

Problems

  • * dropped packets
  • can solve via retransmission.
  • * out of order packets
  • tags packet indices to reconstruct order.
  • * destination buffer overflow, buffer overflow/dropped packets along route

Protocols

UDP (User datagram protocol)

  • * Provides socket address for application-level multiplexing
  • * No flow control or congestion control
  • * No retransmission guarantee

TCP (Transmission control protocol)

  • * Acknowledgement system for reliability and flow/congestion control
  • Infer rate at which packets have been received by returned ACKs
  • * Congestion control
  • reduce transmission rates when overflows are detected downstream
  • * Flow control:
  • Control the amount of traffic ingested into the network. This is done through the use of the send-ack protocol.