众所周知，本地交换机（端局机）至用户之间的线路叫本地环路（用户环路或用户线）。１９９５年７月ＩＴＵ－Ｔ的Ｇ．９０２建议，提出接入网概念。接入网可以部分（主分线器或分线器至用户）或全部（端局机至用户）替代本地环路。所以，有人把接入网称为本地环路。接人网按传 It is well-known that the line between the local switch (end office machine) and the subscriber is a local loop (subscriber loop or subscriber line). July 1995 ITU-T G. 902 proposes to propose the concept of access network. The access network may replace the local loop either in part (main splitter or splitter to user) or all (end machine to user). So, someone calls the access network a local loop. Access network by press