Editing Bit rate (section)

=== Goodput (data transfer rate) ===
{{Main|Goodput}}

''[[Goodput]]'' or '''data transfer rate''' refers to the achieved average net bit rate that is delivered to the [[application layer]], exclusive of all protocol overhead, data packets retransmissions, etc. For example, in the case of file transfer, the goodput corresponds to the achieved '''file transfer rate'''. The file transfer rate in bit/s can be calculated as the file size (in bytes) divided by the file transfer time (in seconds) and multiplied by eight.

As an example, the goodput or data transfer rate of a V.92 voiceband modem is affected by the modem physical layer and data link layer protocols. It is sometimes higher than the physical layer data rate due to [[ITU-T V.44|V.44]] [[data compression]], and sometimes lower due to bit-errors and [[automatic repeat request]] retransmissions.

If no data compression is provided by the network equipment or protocols, we have the following relation:
: goodput ≤ throughput ≤ maximum throughput ≤ net bit rate
for a certain communication path.