Hi

SRA is really the next step up from bit-swapping. When bit-swapping runs out SRA can "sell back" some sync speed for SNR and have room again to bit-swap, then when SNR improves it trades it back for sync speed. This can happen in almost real-time without the line needing a full retrain and so no disruption for the user.

While BT may have some complicated algorithms going on, they can't react in real-time and any changes only take effect after a retrain. SRA is designed to avoid the retrain in the first place.

The problem with SRA generally is compatibility between equipment and that for the vast majority bit-swapping and interleaving was enough to give a stable line without the need for SRA. For those still having problems the SNR just got upped!

Regards

Phil

estimate FTTC 80 down/20 up, actual 76 down/18.5 up