7 byte preamble
1 byte SFD
6 byte dst MAC
6 byte src MAC
2 byte ethertype or length
46-1500 bytes of payload (ignoring “Jumbo” frames and 802.1q tags)
4 byte CRC
12 byte IFG (which is silence, but still counts for time on the wire)
Add it up and you have 1538 bytes “on the wire”.
TCP overhead for IPv4 is 20 bytes for IP(v4) (no options) and 20 bytes for TCP (again, no options).
So 1460 bytes of data for 1538 bytes on the wire. 1460/1538 = 0.949284
So for 100M Ethernet, 94.9284Mbps is “perfect”.
7 byte preamble
1 byte SFD
6 byte dst MAC
6 byte src MAC
2 byte ethertype or length
46-1500 bytes of payload (ignoring “Jumbo” frames and 802.1q tags)
4 byte CRC
12 byte IFG (which is silence, but still counts for time on the wire)
Add it up and you have 1538 bytes “on the wire”.
TCP overhead for IPv4 is 20 bytes for IP(v4) (no options) and 20 bytes for TCP (again, no options).
So 1460 bytes of data for 1538 bytes on the wire. 1460/1538 = 0.949284
So for 100M Ethernet, 94.9284Mbps is “perfect”.