> Hi all,
> I recently had one of my non-technical colleagues ask me an interesting
> questing - how fast is ethernet data transmitted over a UTP cable? So
> what he was really asking is "what is the average latency of an
> electrical signal over copper cabling?". I've done some googling but
> can't find a definitive answer to this. I know that as a rule of thumb
> the speed of light is reduced to around 0.66c in a fibre, so you could
> say that the signal travels through the fibre at 2/3 the speed of
> light. What is the equivalent for an electrical signal in copper?
> ...note that I'm only asking about the signal propagation time in the
> cable. The processing delay of the equipment at each end of the cable
> is a seperate issue.
I highly recommend getting a copy of "Ethernet: The Definitive Guide"
The discussion about Ethernet specifications, specifically minimum and
maximum cable lengths explains the round-trip propogation delay in
detail. If memory serves me correctly I want to say that the maximum
time between any two devices in a broadcast domain is something like
26.5 micro-seconds for a maximum round-trip time of 53 micro-seconds.
I think it's something like that but frankly I can't recall with any
degree of certainty. I recommend the book to everyone in networking.
I've found that the concepts it outlines are applicable in everything I
do in networking every day.