On Sun, 18 Jul 1999 [EMAIL PROTECTED] wrote:

> >     I mean Mega as in 1000000.  100Mbps Ethernet should be equal to
> > about 12500Kbytes/sec which is equal to 12.5Mbytes/sec.  94.93Megabits/sec
> > doesn't equal to 100Megabits/sec.
> 
> 12.5 Mbytes/sec on the wire *is* 94.93 Megabits/sec application to
> application using TCP - that's what I'm trying to say. You'll never see
> 12.5 Mbytes/sec application to application - look up the Ethernet frame
> formats to see why (1460 bytes of TCP payload is 1538 bytes on the wire).

        I guess I forgot about the overhead.  I've tested between two
FreeBSD machines using Intel Pro100+ NIC cards connected to a Cisco 2924XL
Switch Full Duplex and never seen anything close to the speeds.

> > > I've measured 94.87 Mbps myself on full duplex 100BaseTX (back to back
> > > with a crossover cable or through a switch).  This is close enough to
> > > the "speed of light" that I see no point in trying to improve on it...
> > 
> >     Yeah but what's the transfer rate you get?
> 
> 94.87 Mbps, application to application, using ttcp. Using Mega = 1000000,
> that should be 11.86 MBytes/sec.
> 
> Oh yeah, this was measured with FreeBSD, with a P-133 on the receving end,
> back in '96 :-)

        Hmmm, how did you do the measurement and how big of a file does it
need?

        With a 122MByte file, it only does 2644Kbytes/sec.  This is
between two Pentium II 450 machines with Intel Pro100+ NICs.


Cheers,
Vince - [EMAIL PROTECTED] - [EMAIL PROTECTED]           ________   __ ____ 
Unix Networking Operations - FreeBSD-Real Unix for Free / / / / |  / |[__  ]
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