I have a familiar problem, but if there was a direct answer to my specific twist on the forums here, I'm missing it.
I have two devices that establish a stream connection and pass messages over the socket. I want some way of knowing when there's any break in the socket communications - preferably within milliseconds, but I can imagine compromising on this if the message load is too great.
I can detect link loss from the PHY...but that won't help if the break is somewhere between two hubs and not between my device and the hub, since the link to the hub will still be active.
And it seems as if the RFC specs for TCP sockets put the minimum timeouts in minutes, not seconds, much less milliseconds.
Is there any easier way other than setting up a periodic message and a watchdog timer? (Or perhaps a reason why even this won't work?)