Wire lengths for communication testing

When testing device communications, is it prudent to specify tests for the medium's boundaries? For example: using a 100 meter length of
CAT5 cable to test TCP communication, or 4000 feet of shielded twisted pair cable to test RS-485 at 9600 bps.
Does OEM equipment generally get tested in this way?
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snipped-for-privacy@yahoo.com wrote:

Is there another way to be sure that the equipment meets its specifications? After all, those distances are minimums.
Jerry
--
Engineering is the art of making what you want from things you can get.

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says...

Due to practical limitations, like actually running out 4,000 feet of cable (rather than leaving it on the spool, which is NOT the same thing), it's common to simulate long cable by adding resistance and capacitance to a short cable. Though if you're building a TDR, you really do need all that cable, and you have to MEASURE it too...
--Gene
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