Packet transfer delay

Packet transfer delay is a concept in packet switching technology.

The sum of store-and-forward delay that a packet experiences in each router gives the transfer or queuing delay of that packet across the network. Packet transfer delay is influenced by the level of network congestion and the number of routers along the way of transmission.

There are four sources of packet transfer delay:

1. Nodal processing:
   1. Check bit errors
   2. Determine output link
2. Queuing:
   1. Time waiting at output link for transmission
   2. Depends on congestion level of router
3. Transmission delay:
   1. R=Link bandwidth (bit/s)
   2. L=Packet length (bits)
   3. Time to send bits into link = L/R
4. Propagation delay:
   1. d = Length of physical link
   2. s = Propagation speed in medium
   3. Propagation delay = d/s