在电信新业务中,“汇线通”是虚拟用户交换机(CENTREX)的俗称。它是将公众电话交换网(PSTN)上局用交换机的部分用户(尤其是集团用户,如:学校、机关、医院、工矿企业等)划分为一个个用户群,每个群内可设话务员、辅助出群、入群及群内呼 In the new telecommunications business, “Huitian Tong” is the common name of Virtual Subscriber Exchange (CENTREX). It divides a part of users (especially group users, such as schools, institutions, hospitals, industrial and mining enterprises, etc.) in the public exchange over the PSTN PSTN into one user group. Each group may have attendants, Assisted out of the group, into the group and within the group call