Is there a cheap box that will show, via some LEDs, if there is
traffic flowing in an ethernet cable (up to gigabit, all four pairs).
Doesn't need to know anything about the data just that data is
flowing. It must not interfere with the data or upset the connection,
so I don't think a T connection and a cheap switch will work and I'd
rather it was line powered.

I have a sneaky feeling that a simple buffer driving an LED for each
pair won't work as the volts waggle all the time due to the DC
compensation and NRZI coding.

--
Cheers
Dave.

Dave Liquorice wrote:

Is there a cheap box that will show, via some LEDs, if there is
traffic flowing in an ethernet cable

You seem to have ruled out the simplest way of doing it, just use two
ports of a switch, no need for any "T" just use two ports and an extra
cable.

On 22/04/16 09:00, Andy Burns wrote:
Dave Liquorice wrote:

Is there a cheap box that will show, via some LEDs, if there is
traffic flowing in an ethernet cable

You seem to have ruled out the simplest way of doing it, just use two
ports of a switch, no need for any "T" just use two ports and an extra
cable.

+1


--
The theory of Communism may be summed up in one sentence: Abolish all
private property.

Karl Marx

On Fri, 22 Apr 2016 09:00:09 +0100, Andy Burns
wrote:

Dave Liquorice wrote:

Is there a cheap box that will show, via some LEDs, if there is
traffic flowing in an ethernet cable

You seem to have ruled out the simplest way of doing it, just use two
ports of a switch, no need for any "T" just use two ports and an extra
cable.

I assume you are monitoring for unauthorised use. What about the ARP
traffic and other housekeeping stuff that occurs when two NICs are
connected?



--

Graham.

%Profound_observation%

On 22/04/16 12:43, Graham. wrote:
On Fri, 22 Apr 2016 09:00:09 +0100, Andy Burns
wrote:

Dave Liquorice wrote:

Is there a cheap box that will show, via some LEDs, if there is
traffic flowing in an ethernet cable

You seem to have ruled out the simplest way of doing it, just use two
ports of a switch, no need for any "T" just use two ports and an extra
cable.

I assume you are monitoring for unauthorised use. What about the ARP
traffic and other housekeeping stuff that occurs when two NICs are
connected?



Its pretty low


--
Canada is all right really, though not for the whole weekend.

"Saki"

On Fri, 22 Apr 2016 12:43:57 +0100, Graham. wrote:

I assume you are monitoring for unauthorised use. What about the ARP
traffic and other housekeeping stuff that occurs when two NICs are
connected?

No just want to see if the link is working. Something that can sit in
circuit and not consume any external power. Having engaged brain a
bit more the lights on any connected kit would do but there might not
be any connected kit and connecting kit, if there is any available,
might not be convenient. So it boils down to a line powered "is there
a live switch on the other end of this cable?"

That ain't going to work as there is no DC coming out of a live
switches port. I guess their might be the "carrier" of a few tens of
MHz but detecting that is starting to get complicated. Think it's
time to go back to sleep and just have a spare switch kicking about.
B-)

--
Cheers
Dave.