·Time Warner Cable
I don't think so - its part of the error correction scheme if I'm not mistaken.
'Fast path' vs. 'Interleaved'.
I remember when I had DSL Extreme - they allowed me to have FastPath - and I had something like 8ms to the first hop on 3Mbps DSL. When I had it on AT&T it was somewhere around 15ms.
Interleaving adds latency but is a bit more tolerant to line conditions.