| C/O(central office) | 市话局 |
| C,C++ | C语言,C++语言 |
| CA(Certificate Authority) | 认证机构 |
| cable head | 光缆头端 |
| CABS(Carrier Access Billing System) | 运营商接入计费系统 |
| caching | 高速缓存 |
| CAD/CAM(Computer-aided Design/Computer-aided Manufacturing) | 计算机辅助设计/计算机辅助制造 |
| CAI(Common Air Interface) | 公共空中接口 |
| CALEA(Communications Assistance to Law Enforcement Act) | 协助“执行法律法”的通讯系统 |
| call blocking | 通话限制 |
| call center | 呼叫中心(客户服务中心) |
| call detail recording | 通话详细纪录 |
| call forwarding | 呼叫转移 |
| call forwarding(busy) | 遇忙转移 |
| call forwarding(no answer) | 无应答转移 |
| call forwarding(variable) | 呼叫转移 (可设置) |
| call hold | 来电保留 |
| call set-up | 呼叫建立 |
| call tear down | 结束呼叫 |
| call type | 呼叫类型 |
| call waiting | 来电等待 |
| caller ID(caller identification) | 主叫用户识别 |
| calling party pays | 主叫用户支付 |
| CALLS(Coalition for Affordable Local and Long Distance Service) | 提供低价长途和地方通讯服务联合会 |
| CAP(Carrierless Amplitude and Phase Modulation ) | 无载波相幅调制 |
| CAP(Competitive Access Provider) | 竞争接入服务商(竞争信息服务的网络公司) |
| CAP Code | 传呼号码 |
| CARE(Customer Account Record Exchange) | 用户账目记录交换 |
| carrier | 运营商,电信公司 |
| carrier line charge | 地方电话公司向长途电话公司收取的接入费用 |
| CAS(Channel Associated Signaling) | 信道关联信令 |
| CATV(Community Antenna Television) | 共用天线电视 |
| CAVE(Cellular Authentication and Voice Encryption) | 无线认证与语音加密 |
| CB(Channel Bank) | 通道墙 |
| CBP(Convergent Billing Platform) | 融合计费平台 |
| CBQ(Class-Based Queuing) | 根据类别排队 |
| CBR(Constant Bit Rate) | 恒定位速率 |
| CC(Cluster Controller) | 簇控制器 |
| CC&B(Customer Care and Billing) | 客户服务与计费 |
| CCB(Common Carrier Bureau) | 公共电信局 |
| CCIS(Common Channel Interoffice Signaling) | 公共信道局间信令 |
| CCITT(Consultative Committee for International Telephony and Telegraphy) | 国际电报电话咨询委员会 |
| CCL(Carrier Common Line) | 公共线 |
| CCS(Common Channel Signaling) | 公用信道信令 |
| CCSA(Common Control Switching Arrangement) | 公用控制开关排列 |
| CD(Collision Detection) | 冲突检测 |
| CDDI(Copper Distributed Data Interface) | 铜线分布数据接口 |
| CDMA(Code Division Multiple Access) | 多址分码 |
| CDN(Content Delivery Network) | 内容发布网 |
| CDPD(Cellular Digital Packet Data) | 蜂窝数字分组技术 |
| CDPN(Called Party Number) | 被叫号码 |
| CDR(Call Detail Record) | 通话详细纪录 |
| cell site | 单元位置 |
| cellular | 蜂窝技术 |
| cellular hand-off | 移动通讯交接,手机漫游 |
| CELP(Code Excited Linear Prediction) | 编码激励线性预测 |
| CO(Central Office) | 市话局 |
| co-location | 并置 |
| coax(coaxial cable) | 同轴电缆 |
| Coc(central office connection) | 局端联接 |
| CODEC(Coder/ Decoder) | 编码译码器/编解码器 |
| collection policy | 收款政策 |
| collections | 收款 |
| COM(Component Object Model | 组件对象模型 |
| commission | 佣金 |
| commodity | 商品 |
| Communications act of 1934 | 通信法(1934) |
| Communications protocol | 通信协议 |
| compression | 压缩 |
| CompTEL(competitive telecommunications association) | 竞争电信协会 |
| convergence | 融合 |
| cookie | 小甜饼(web服务器返回给用户的信息块) |
| cooper loop | 铜缆 |
| CORBA(Common Object Request Broker Architecture) | 通用对象请求代理机构 |
| COS(Corporation for Open Systems) | 开放系统协会 |
| COSMOS(Central Office System for Mainframe Operations) | 主机操作市话局系统 |
| COT(Central Office Terminal) | 中心局终端 |
| COTS(Commercial Off-The-Shelf) | 非定制产品 |
| country code | 国家代码 |
| coverage area | 覆盖区 |
| CP(Customer Premise) | 用户终端 |
| CPCN(certificate of public conveyance necessity) | 公用传输必备证书 |
| CPE(Customer Premise Equipment) | 用户终端设备 |
| CPN(Calling Party Number) | 主叫用户号码 |
| CPNI(Customer Proprietary Network Information) | 用户私有的网络信息 |
| CPS(Cycles Per Second) | 周/秒,赫 |
| CPU(Central Processing Unit) | 中央处理器 |
| cramming | 补充 |
| CRC(Cyclical Redundancy Checking) | 循环冗余校检 |
| credit | 信用 |
| credit analysis | 信用评估 |
| credit class | 信用等级 |
| credit limit | 最高信贷额 |
| credit risk | 信用风险 |
| credit scoring | 信用评值 |
| CIRS(Customer Record Information System) | 客户记录信息系统 |
| CRM(Customer Relationship Management) | 客户关系管理 |
| CSA(Carrier Serving Area) | 市话服务范围 |
| CSMA/CD(Carrier Sense Multiple Access with Collision Detection) | 带有冲突检测的载波感应与多路存取 |
| CSITL(Customer Service Information Tech. Lab) | 客戶服务咨询技术研究室 |
| CSR(Customer Service Record) | 客户服务纪录 |
| CSR(Customer Service Representative) | 客户业务代表 |
| CSU(Channel Service Unit) | 信道服务单元 |
| CSU/DSU(Channel/Digital Service Unit) | 信道维护/数据服务二合一部件 |
| CTI(Computer Telephone Integration) | 电脑电话整合 |
| CTIA(Cellular Telecommunications & Internet Association) | 蜂窝通信和网络协会 |
| CVSDM(Continual Variable Slope Delta Modulation) | 连续变量斜率增量调制 |