cancel
Showing results for 
Search instead for 
Did you mean: 

Interleaving

dnpark38
Rising Star
Posts: 432
Thanks: 16
Registered: 24-02-2015

Interleaving

I keep reading this term, interleaving, and it is something the BT DLM does to us I think prior to dropping our Sync. speeds, what is it please and how do we know when on it, seems to a feared thing to some.
http://www.thinkbroadband.com/speedtest/button/1476198475230638155-mini.png
2 REPLIES
sjptd
Grafter
Posts: 486
Thanks: 4
Registered: 01-09-2014

Re: Interleaving

When the line gets errors there are ways of correcting them by adding extra error correction data mixed in with the 'real' data.  That error correction data is overhead, so the amount of useful data that can be transmitted goes down.
The errors tend to come in bursts, so a burst may completely wipe the data so even with the correction it can't be interpreted.  If the data packets are spread out over time slightly the errors hit the data is a more spread out way, so each packet usually suffers only partial loss and survives enough that it can be put back together again.  That spreading out of each packet over time is called interleaving.
The bad thing about interleaving is that with the spread out packet the data can't be read till the last part of the packet arrives.  This increases the latency, which gamers in particular hate.  The typical increase in latency is 8ms, but it can be more if the errors are really bad.
Terranova667
Pro
Posts: 1,297
Thanks: 75
Fixes: 3
Registered: 19-02-2014

Re: Interleaving

In more simpler term Interleaving is used to make the line more stable if DLM thinks there is to much noise on it and it does this by knocking off some of the speed, as Sjptd stated it also increases Ping / latency, once DLM thinks the noise is no longer a problem it will remove the interleaving and such you should gain back the speed and the ping / latency will drop back down this however can take weeks to happen.