Those figures look much better.. 7616 is full sync and what your line should be able to achieve.
The 20dB Noise Margin is now telling us, not your Target SNR, but the fact that your line is actually capable of speeds much higher than 8Mb when adsl2+ becomes available.
At the moment that line is running well... so this fits in with the fact that theres no interference on the telephone line.
>> One point. Could it be interference from a nearby network? I am using the default channel ie 11.
I dont think its anything to do with the wireless channel.. its far more likely to have been some form of interference from a nearby electromagnetic source.
Usual culprits are monitors, TVs, PIR lighting or some faulty electrical equipment. These may either be in your own property or a neighbouring one.
Your latest stats seem to show that whatever it was has cleared for now.... lets hope it stays that way
What we normally recommend if this becomes an intermittent or frequent problem is installing
routerstats which can be set up to constantly monitor and record your line stats.