I created a network at my main base with an inventory connector at 70,65,20.
I then dug a tunnel with cable up to 126,15,500.
When I connected a terminal, it did not show the contents of the inventory network.
We configured the server to keep every chunk that the cable crosses active, and that solved that problem.
I then continued the tunnel until something like 126,15,2000.
When I connected a terminal, it did not show the contents of the inventory network.
I went back to the base, and even there, terminals connected to that same cable also don't show the contents of the network.
If I cut the cable near the base, those terminals start working again.

Ah, good to know. Might be useful to show the current network length and maximum when right-clicking an inventory block.

There is a maximum cable limit, you can change it in the server config. Default is 2048 cables maximum in the entire network.