Found a snapshot log of a previous resync in effect:
Wed 14 Sep 2016 18:19:25, Noise Margin (dB)= 6.2, Connection Speed (Kbps)= 55000, Upstream NM= 6.1, Upstream Sync= 8004
Wed 14 Sep 2016 18:19:40, Noise Margin (dB)= 6.2, Connection Speed (Kbps)= 55000, Upstream NM= 6.1, Upstream Sync= 8004
Wed 14 Sep 2016 18:19:55, Noise Margin (dB)= -0.7, Connection Speed (Kbps)= 55000, Upstream NM= 5.9, Upstream Sync= 8004
Wed 14 Sep 2016 18:20:10, Noise Margin (dB)= -2.9, Connection Speed (Kbps)= 55000, Upstream NM= 4.7, Upstream Sync= 8004
Wed 14 Sep 2016 18:20:25, Noise Margin (dB)= , Connection Speed (Kbps)= 0, Upstream NM= , Upstream Sync= 0
Wed 14 Sep 2016 18:20:40, Noise Margin (dB)= , Connection Speed (Kbps)= 0, Upstream NM= , Upstream Sync= 0
Wed 14 Sep 2016 18:20:55, Noise Margin (dB)= 6.4, Connection Speed (Kbps)= 42156, Upstream NM= 6.1, Upstream Sync= 6801
Wed 14 Sep 2016 18:21:10, Noise Margin (dB)= 6.4, Connection Speed (Kbps)= 42156, Upstream NM= 6.1, Upstream Sync= 6801
Wed 14 Sep 2016 18:21:28, Noise Margin (dB)= 6.4, Connection Speed (Kbps)= 42156, Upstream NM= 6.2, Upstream Sync= 6801