Integrated Services Digital Network (ISDN); Completion of Calls on No Reply (CCNR) supplementary service; Service description
综合业务数字网(ISDN);完成无应答呼叫(CCNR)补充业务;服务描述
发布日期:
1998-10-01
第1阶段完成无应答补充业务呼叫的服务描述
Stage 1 service description of the completion of calls on no reply supplementary service