Interleaving on DSL is enabled by many providers which allegedly provides some packet loss protection at the cost of some latency.

I think it's designed mainly Layer 1 line noise, but now I'm wondering if it might also translate to other benefits, even on a clean DSL line that doesn't *need* interleave.

Question:
Is interleaving protective of packet loss due to momentary spikes on the downloads?

I tested it a bit  with the help of my ISP 

VDSL:
Interleave+FEC On (15ms first hop) 3% packet loss on steam download stress
Interleave+FEC OFF (4ms first hop) 5-6% packet loss on steam download stress  

With fq_codel: (-15% bw)
Both had 0.3% packet loss (very good) on steam Download stress 

Of note, steam downloads used to break fq_codel for me (20 flows split evenly is how they designed it *sigh*) but it appears that it's working well now, perhaps steam *finally* fixed their stuff. Steam stress is performed by downloading any of their free games with their client software e.g. Dota2.

tl-dr; interesting to test weather interleave+FEC, a technology designed for layer 1 noise, can help with layer 3 ingress contention for resources.

Also, I found a guy who designed a layer 3 FEC protocol designed for terrible connections: https://github.com/wangyu-/tinyfecVPN

If anyone wants to comment on that, I think it's nice to know that it exists.