Summary

Recommendation ITU-T L.19 describes some general considerations on services and systems, such as ISDN and xDSL, to be supported by the access network. Some requirements for the digital local line characteristics are also given, as a factor contributing to the provision of good quality of service to the users. Furthermore, some issues for the use of multi-pair copper network cable supporting shared multiple services such as ISDN/xDSL are also described. This revision updates Recommendation ITU-T L.19 to include recent new or revised Recommendations for ADSL2 (ITU‑T G.992.3, ITU-T G.992.4), ADSL2plus (ITU-T G.992.5) and VDSL (ITU-T G.993.1).