From tbb:
For those of you with the Billion 7800N you've probably noticed under config>wan>adsl mode>wan interface there's a "PhyR" setting for downstream/upstream which is not ticked by default. I've just found out from Billion support today that PhyR (pronounced fire) is a new technology from broadcom which delivers a ten-fold improvement in noise resilience against impulse noise and delivers a reduction in bit error rates. (http://forums.thinkbroadband.com/dslrouter/t/4027997-billion-7800n-impulse-noise-protection.html)
No use to me on FTTC, but others might like to play with it.
I read this a while ago but never found out whether it applies to adslmax or adsl2+ and whether the dslam has to support PhyR as well.
Mine is ticked by default for downstream. I've just ticked the upstream box, so we'll have to wait and see. Currently my line is retraining after problems so time will tell. My upstream is currently having a problem so hopefully this may help :shrug:
Thanks, Bill, that might be useful.