from
The Free On-line Dictionary of Computing (8 July 2008)
Maximum Transmission Unit
MTU
<networking> (MTU) The largest number of bytes of "payload"
{data} a {frame} can carry, not counting the frame's header
and trailer.
A frame is a single unit of transportation on the {data link
layer}. It consists of header data plus data which was passed
down from the {network layer} (e.g. an {IP} {datagram}) plus
sometimes trailer data.
An Ethernet (V2) frame has a MTU of 1500 bytes but the size of
the frame can be up to 1526 bytes (22 byte header, 4 byte CRC
trailer).
See also {fragmentation}.
(2000-10-07)