sync change downwards

Hi there. I have been on max adsl for over three months now and have always synced at 8128. Over the last week or so my sync rate has droped to 7616. What might have cused this to happen and can I raise it back to 8128 Thank's for any help with this.

Intereleaving has probably be applied due to errors.
You can ask your ISP to contact BT and turn interleaving off, but TBH, unless latency is an issue for you e.g. gaming/internet phone/video conferencing, you are probably better off leaving it alone

Nice one. Thank's for your reply m8.

Wrong I am afraid, interleaving is turned on in order to maintain a higher sync!
Don't worry you are not the only one to have this misconception - someone is spreading misinformation around these parts.

The chances are that the OP just had a burst of noise on his line (thunderstorm, street lights etc) and this caused his router to re-sync.

Provided the original source of the noise has gone, the simple way to deal with this is to reboot the router. It will then sync at the higher rate again. Routers will automatically sync at a lower rate when the line conditions deteriorate but do not automatically reboot when they improve.

ADSL Max is "rate adaptive". When a router or modem is booted up the highest possible sync rate is adpoted for the line conditions. The critical parameter that limits the sync rate is the background electrical "noise". If there is too much noise relative to the signal then the signal will start to be drowned out by the noise. When this happens errors creep in.

There are two basic ways to deal with this:
1. Reduce the sync rate
2. Correct the errors

Most routers are designed to resync at a lower speed when errors creep in. This is what happened to the OP.

If this happens too often then the ADSL Max system will introduce an error correction system called "interleaving". This allows the router to maintain a higher sync rate, but the penalty is slower pings.

This will not bother most people as ping speed is important only for certain types of online gaming (FPS mainly) and poor pings can affect sound quality on VOIP connections - particularly international calls.

The bottom line then is, unless you use VOIP or are an avid player of on-line first person shootups, then just leave things as they are. If you get very occasional drops in your sync there is no harm in rebooting your router to bring the sync back up again.

However, if you find you are rebooting more often than once every 3-4 days then don't bother as it will not improve your actual data throughput. Certainly rebooting every day is totally pointless.

Actually, to be completely accurate, Interleaving is not itself an error correction technique it simply allows error correction a better chance to correct the errors when the data is uninterleaved, so to speak, at the receive end. However, on MAX when BT apply Interleaving they also apply maximum Forward Error Correction though FEC is separate from Interleaving and is an error correction method that works by sending additional error correction data along with the data stream . Interleaving adds latency due to the additional time taken to interleave the data stream while FEC reduces data throughput as a certain portion of the data bandwidth is used to transmit the extra data required for FEC.