B-channel / B 信道 B-ISDN, broadband integrated services digital network / 广播综合业务数字网络 backbone router / 主干路由器 background program / 后台程序 backup domain controller, BDC / 备份域控制器 backup media pool / 备份媒体池 backup operator / 备份操作员 backup set / 备份集 backup set…