Metrikák

• Eredeti ARPANET metrika

  • measures number of packets enqueued on each link
  • took neither latency or bandwidth into consideration

• New ARPANET metric

  • stamp each incoming packet with its arrival time (AT)
  • record departure time (DT)
  • when link-level ACK arrives, compute
    • Delay = (DT - AT) + Transmit + Latency
  • if timeout, reset DT to departure time for retransmission
  • link cost = average delay over some time period

• Fine Tuning

  • compressed dynamic range
  • replaced dynamic with link utilization

Notes: