[j_s]

Very granularly: simple tools like the Windows Task Manager Performance tab's Ethernet Throughput graph can provide enough of a clue that a network connection is suffering.

There are many utilities that show this info in useful form in the system tray; perhaps some would be able to superimpose it on top of the video conferencing software (like OnTopReplica).

[ryanianian]

I often have such OS-level tooling open during VC chats, but it's not natural to have to keep an eye on another tool, especially when you want the "last seen"/latency figure nearly instantaneously so you know the context for lack of signal (human vs machine).