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Re: Jumbo Frames?



On Wednesday 01 Feb 2006 08:29, mike wrote:
> ..... I could
> get anywhere from 100-117MB/sec. Which isn't a problem -
> theoretically, gigE can only give me 125MB/sec anyway... so
> 116-117MB/sec I think is really good, so I am happy now. :)

The figure you have is about right.  Yes there are 8 bits in a byte, so you'd 
expect 125MB; but because you're dealing with packets, and not a contiguous 
bit stream  {à la Spectrum cassette loading},  there are overheads -- every 
packet has to have a header and footer, which count against the total.

By using bigger packets, you will have fewer headers and footers -- and so 
improve the transmission rate.

BTW, RS232 serial comms  {old-fashioned modems!}  effectively uses one-byte 
"packets", with a 2-bit overhead.  This is why you have to divide by ten, not 
eight, when converting bits to bytes in serial comms.

-- 
AJS
delta echo bravo six four at earthshod dot co dot uk



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