During a cruise of the fishing vessel m/t "Sagitta" around the Antarctic, the occurrence of DSL was noted in a small area of the Pacific sector of the Antarctic waters. The layers were found at depths of 50—150 m. Their main component was E. carlsbergi (family Myctophidae), whose maximum density was within the range of 219—437 x 10 -4 fish/m3.

This article presents a review of the investigation of the possibility of increasing the efficiency of existing line test solutions for troubleshooting testing for IPTV over xDSL, by the results of experimental research on real system under commercial exploitation. At the beginning of this article the main weaknesses of the existing troubleshooting testing are described. In the continuation of the article the physical layer parameters of xDSL transceiver are listed. This article also provides a few specific examples of xDSL lines with their physical layer parameters of xDSL transceivers followed by analysis how they can be used for the purposes of more efficient measurement of parameters of copper pairs.