I know that there is 25 and even 300 pair cat 5.
But what is the use for it ??
To consolidate multiple 4 pair network cables by running the 25 pair and then using the cat 5 66 block to branch out to 4 pair cables that end up at the user location ???
Seems like more trouble than it is worth.
As for using a spare pair from a network cable to run a voice circuit to a location, I would be careful of that to make sure the network isn't 1000base-t which uses all 4 pairs.
