Why MTU for ethernet is limited to 1500?
Well, MTU(maximum transmission unit) for ethernet is limited to 1500 only.That is because of following main two reasons:
1. When the frame size is too high then chances of signal at physical media being corrupted will be high.And, if there is even a single byte, entire frame needs to be re transmitted which aids overhead significantly.Also, large frame size delays the signal follow.
2. As per the Ethernet frame standard 802.3 there is 2 byte Length field and Ethernet frame standard II there is 2 byte Type field.Based on that numerical 2 byte field Ethernet standard being used will be distinguished.If numerical value is more than 1500 in decimal then it signifies Ethernet standard -II else it signifies Ethernet standard 802.3.
In case the packet size is such that it exceeds the MTU then fragmentation needs to be done.
1. When the frame size is too high then chances of signal at physical media being corrupted will be high.And, if there is even a single byte, entire frame needs to be re transmitted which aids overhead significantly.Also, large frame size delays the signal follow.
2. As per the Ethernet frame standard 802.3 there is 2 byte Length field and Ethernet frame standard II there is 2 byte Type field.Based on that numerical 2 byte field Ethernet standard being used will be distinguished.If numerical value is more than 1500 in decimal then it signifies Ethernet standard -II else it signifies Ethernet standard 802.3.
In case the packet size is such that it exceeds the MTU then fragmentation needs to be done.
Comments