Problem

problem happened in the network

data loss

delay

• processing, time spent in router, check bit error, determine output link
• queueing, depends on congestion level
• transmission delay: L/R bits/ bps
• propagation delay: d/s (length/2*10^8)
• $\lambda$ = avg packet arrival rate(pts/s), traffic intensity: $L \lambda /R$ value -> 1, delay becomlarge.
• nodal delay = $d_{proc}+d_{queue}+d_{trans}+d_{prop}$

measurement

• tracerouter algo:
  • for all router i:
    • send three packets to router i
    • router i will return packets to sender
    • measure transmission and reply interval