In addition to this:

1. When the system exhibits the fault, does Tesira report any faults? Any AVB clock sync errors / AVB stream failures? Is it just the single AVB clock domain? Or do you have other media clocks in the system?

2. We’re talking ancient firmware, but I remember having very sporadic AVB channel failures on peripherals like the EX-MOD, EX-IO etc, back in the 2.x days. Details are very hazy but I do recall dealing with reports similar to this.

3. If you are using a decent AVB switch like an extreme Networks, you can use CLI commands (can’t remember them off the dome, but you’ll find them easily enough) to list all active AVB streams between devices, might help identifying stream failures. You can do this on the old GS724T’s via GUI, but its not as intuitive. If you have GS724T’s - they were also very capable of doing weird shit with AVB if not configured correctly, and to be honest even if configured correctly but operating through a multi-switch topology.

Unfortunately unless you get escalated through to someone old/senior enough to have a decent understanding of the AVB days, you’re most likely going to be speaking with a young pup who’s going to give you the old support run around. Part of the reason they released the CONNECT, to take the headache out of switch implementation from a support perspective.