Depending on the physical layer protocol or encoding used, the pause may be necessary to allow for receiver clock recovery, permitting the receiver to prepare for another packet (e.g. powering up from a low-power state) or another purpose.
[2]: 5 During data reception, some interpacket gaps may be smaller due to variable network delays, clock tolerances (all speeds), and the presence of repeaters (10 Mbit/s only).
Some manufacturers design adapters transmitting with a smaller interpacket gap for slightly higher data transfer rates.
[4][5] For Fibre Channel, there is a sequence of primitives between successive frames, sometimes called interframe gap as well.
[6] Each primitive consists of four channel words of 10 bits each for 8b/10b encoded variants (1–8 Gbit/s), equivalent to four data bytes.