ISDN services include telephone, data, electronic mail, and facsimile.
ISDN services include telephone, data, electronic mail, and facsimile.
综合业务数字网义务包括电话、数据、电子邮件和传真。
ISDN services include telephone, data, electronic mail, and facsimile.
综合业务数字网义务包括电话、数据、电子邮件和传真。