MTU and data splitting

MTU and data splitting

When a packet is sent from a source to a destination, it is delivered to the destination via various communication lines.

 MTU is specified for communication lines. MTU (Maximum Transmission Unit) is the maximum transfer unit and the maximum data length that can be transferred.

The MTU for each communication line is defined as follows.

data linkMaximum MTU
IEEE 802.3 Ethernet1,492
IP over ATM9,180
TokenRing 4Mbps IEEE802.54,464
TokenRing 16Mbps IBM17,914

Fragmentation (division process)

 Since the MTU is determined for each communication line, when passing through a communication route with a smaller MTU than the packet length, the packet is fragmented and divided according to the smaller MTU size. If you don't do it, you won't be able to pass through the communication line.