I have been unable to get my modem/router to sync with the exchange unless beforehand I lift the phone off hook and replace it after a second or two.
After the line sync's I can see a SNR of anything up to 12dB - this gradually drops until the line looses sync again (usually over a number of hours)
If I keep monitoring the line SNR on my router stats page, I see that if I again take the phone off hook the SNR rises again. By doing this, I can keep the line synced for a longer period of time.
I am using an ADSLnation faceplate, with no external wiring and only a single phone connected (along with my modem/router)
Have tried a new cable between router and socket
Have tried a new router
Have tried removing faceplate and connecting router with an external filter.
I have no noise on the phone circuit.
ISP is f2s, connection is up to 8mb on a BT line.
Currently synced at 512kbps which is 1.5mbps lower than my usual sync speed.
Due to the 99 quid Openreach charge I really want to be 100% sure that it's BT's network before I report the fault.