Size of Ethernet frame - 24 Bytes Size of IPv4 Header (without any options) - 20 bytes Size of TCP Header (without any options) - 20 Bytes So total size of empty TCP datagram - 24 + 20 + 20 = 64 bytes

total size of TCP datagram with 1 char - 24 + 20 + 20 + 1 = 65 bytes