Define: a measurement (typically in bytes) of the largest data packet a device can accept via an internet connection
Ethernet: 1500 B
if too small: overhead issue
if too large: resubmission issue
need to find a sweet point
0.1 potential issues of package
loss: client can retransmit based on acknowledgement
reorder: sequence number
modification: checksum, digital signature
latency
RTT (round-trip time): the amount of time it takes for a signal to be sent plus the amount of time it takes for acknowledgement of that signal having been received
0.2 Four types of delay
1) Transmission delay:
the time taken by the physical layer at the source to transmit packets over a link
example: 1500 bytes / 1 Mbps = 1500 * 8 bits / 1e6 bps = 0.012 s = 12 ms
i.e. the time to go through the check on the highway
2) Propagation delay:
the amount of time required for a signal to be received after it has been sent
i.e. the time to reach the destination
3) Processing delay:
(router/switch) the time required to examine the packet’s header and determine where to direct the packet