Path: news.eternal-september.org!eternal-september.org!.POSTED!not-for-mail
From: Don Y <blockedofcourse@foo.invalid>
Newsgroups: sci.electronics.design
Subject: Mid-span ethernet monitor
Date: Fri, 6 Jun 2025 20:38:55 -0700
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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.

I can tolerate brief interruptions in traffic (e.g., during "testing")
and even continuity (less desirable but tolerable as the testing is
only sporadic)

Active, in-line solutions are complicated by power delivery over the pairs.
So, I'm wondering if I could passively monitor signals coming in/out and
communicate that status through a different channel?

Cost isn't too critical.  Though physical size might be.  (the wet-dream ideal
would be something that could fit in a 8P8C coupler)