ISDN 综合业务数字网
ISDN Router路由器
ISDN support综合数字业务网
over ISDN线路接口
ISDN PRI配置;基群速率接口
ISDN technologyISDN技术
ISDN技术ISDN technology
ISDN DCC的配置
N-UNCOUNT（不可数名词） ISDN is a telephone network that can send voice and computer messages. ISDN is an abbreviation for "Integrated Service Digital Network." 综合业务数字网
...an ISDN phone line.
…一条综合业务数字网电话线。