>> I’m assuming these spikes are SHINE, big noise spikes of fairly short duration.
TBH the traditional methods of error protection doesnt always work with bursts of SHINE. I get a daily burst of SHINE that the DLM has never been able to eliminate despite trying high interleaving and capping me down to 60Mbps when my Maxrate is 80Mbps.
>> downstream interleaving, which imho is bad news. I’m thinking that this is because I have PhyR,
PhyR was developed by Broadcom as
an alternative to a replacement for interleaving which they claimed was end of life.
Broadcom was quite dismissive of Interleaving famously saying it stole your bandwidth and even going so far as to say that on certain lines the scatter of interleaving can cause more problems than it corrects. Retransmission is supposedly 10x more efficient than the traditional interleaving and FEC error protection/correction with less overhead.
Hence typical INP values of 40+ with G.INP retransmission compared to just 3 or 4 INP values without.
What it means:-
- If you have a dsl tone that has 10 bits loaded per bin then the DMT symbol is 10
- The Impulse Noise Protection (INP) value is the amount of DMT symbols that are protected against errors
Traditional interleaving & FEC usually has an INP value of 3 or 4.
- If your DMT symbol is 10 and your INP=3, then the system can recover from (3x10)=30 contiguous bit errors.
Compare with G.INP/Retransmission/PhyR with INP value of 40+
- If your DMT symbol is 10 and your INP=46, then the system can recover from (46x10)=460 contiguous bit errors.. and without the massive continuous overheads.
It entirely depends upon the type of errors your line is experiencing, but when it comes to SHINE usually neither methods are particularly that good. They may be brilliant with low level background noise and small amounts of REIN, but I don't want to limit my connection 24/7 with interleaving for the daily dose of SHINE I get on my line. :/
