I'm not sure whether I've written understandable post earlier and thereby I'm going to say about my problem once again. I know if attenuation is raised about 0.5 dB it isn't line fault. However, I'm not sure whether settings of DSLAM card are the same like earlier. From December 2012 until the 10 May 2013, my router was continously showing line attenuation: 25.5 dB for download and 15.2 dB for upload despire I was doing a lot of reconnectings. On 10 May 2013 at night I had three hours break in Internet connection, I've haven no synchronization. However after the break I was still having 25.5 dB/15.2 dB attenuation. I was curious about cause of that break and thereby I've asked my ISP what was cause of that break because I thought that engineers was doing something. On 10 May 2013 my ISP raised SNR margin to 9 dB and raised "interleave delay". Suddenly I saw 26.0 dB/15.6 dB attenuation and SNR margin 9.1 dB. I've called to my ISP and my ISP restored 6 dB target margin but since 10 May line attenuation is continously 26.0 dB/15.6 dB. I've asked my ISP which settings were changed, however my ISP assures me previous settings (before 10 May) are restored. My ISP assures me that I've default profile on DSLAM card. I don't believe that my ISP restored previous settings because my attenuation raised accurately at the moment of rasing target SNR margin to 9 dB. What setting can be able to raise attenuation? My power output is the same like earlier. Is it possible that my ISP changed PSD masks? Does power output change line attenuation? Additionally, I've seen since I have raised attenuation I have more errored seconds on SNR margin about 4.6 dB than I had earlier.