> However, ethernet at 100Mbit is 4B5B coded at a 125mhz rate. So the raw > synchronous data rate really is 12.5Mbytes/s. Minus the sync preamble > of 8 bytes per packet and the mandatory inter-frame-gap of 12 bytes > that's a physical layer rate of (12.5M * (1500/(1500+20))) or 12.34Mbyte/s.
You need add Ethernet header (14 bytes) + CRC (4 bytes). This means you have a maximum data rate, assuming 1500 byte MTU, of 12.5M * 1500/1538 = 12.19 Mbyte/s. And for those used to powers of two, M here means one million, not 1048576. Steinar Haug, Nethelp consulting, [EMAIL PROTECTED] _______________________________________________ [email protected] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to "[EMAIL PROTECTED]"
