@nunz @BigPipeNZ Please keep us updated once the issue is resolved so we actually know what the issue was
The connection has corrected itself. it seemed better (but did fail at least once) after it was 'reset' by BP. I've no idea what was wrong as they haven't replied to requests for info.
They blamed the modem as it showed < 0.1% (3 out of over 5000 pings in a 20 hour session ) missed on the internal network ping checks. Compared to 70% missing on pings to external network sites - i doubt it. Also as it is now fixed and I've changed nothing on the internal networks it makes no sense.
The internal ping was across a wireless network connection that then routes through two devices to the gateway. I wanted worst possible results if it was an internal issue. 3 pings missed out of 5000 on a busy wireless network with competing channels is acceptable. It could just as possible have been the machine that missed as the network as it was chewing through large data backups across the network at the time.
Still a mystery. thanks for your interest in it.