Well after months and months of fastpath (always had been) my SNR due to cross-talk has gone from 10.5 down to 8.5, a gradual decline.
My line never disconnects and syncs at 80/20.
Then on Sunday gone, it had disconnected at 4:45am ish (no record of disconnects before then indicating any problems) and resync'd as interleaved, latency went up by 8ms. SNR was now 6db and sync rate had dropped to 78,000 from 80,000. The SNR drop is presumably due to extra margin being used up to provide the overheads for interleaving and error correction.
I just accepted it would likely stay this way for a long time.
Now, Wednesday, some 3 days after interleaving was enabled, I've checked this morning and the line dropped at 4:15am and resync'd back to fastpath with a margin of 8.5 as it was before, and back to 80/20.
I was surprised at the quick turn around.
Edited by PhilipD (Wed 11-Feb-15 08:44:42)