Re: Mid-span ethernet monitor

Edward Rawde <invalid@invalid.invalid> wrote:

"Don Y" <blockedofcourse@foo.invalid> wrote in message news:1020c8h$2oq18$1@dont-email.me...

I need a device that can sit midspan (at a "splice point") and monitor
an ethernet connection for integrity.  At the very least, that continuity
exists to both ends of the span.
>
While these are PoE/PoE+ drops, I don't want to place any significant
burden on the PSEs; an external power supply is therefor likely.

 
In that case I'd just put an unmanaged four port non PoE switch at mid run
and look into getting access to the LEDs on the switch which tell me what
the link is doing.
The last design I did which had an ethernet port used KS8721BL

Won't that prevent PoE passing through the link?  This switch will terminate
the PoE and won't pass power or PoE signalling through to the far end.

I suppose you could have some kind of relay box that normally passes the
line through but interposes an ethernet switch (or something else) in the
middle for testing purposes.  When you're in test mode the PoE drops, but
maybe you don't mind that.  Or maybe you do a PoE receiver and PoE injector
to let PoE pass the tester switch.  Some switches can do pair tests:
https://www.engineerkhan.com/networking/testing-an-ethernet-cable-from-a-cisco-switch/

Don't know what a relay would do to signal integrity though.
(it probably has to be mechanical due to isolation requirements)

Theo