- 10-Gigabit Ethernet
- 411
- Answering Machine
- Baseband
- Baseband Unit
- Bell Labs
- Blue Box
- Business Support System
- Call Center
- Call Logging
- Caller ID Spoofing
- Cell Phone Jammer
- Cellular Wideband Audio
- Central Office
- Circuit Switching
- Click-To-Callback
- Code Division Multiplexing
- Collaborative Browsing
- Commercial Mobile Radio Services
- Common Carrier
- Communications Satellite
- Communications System
- Concentrator
- Conference Call
- Consumer Telepresence
- Control Plane
- Core Network
- Current Loop
- Digital Switch
- Direct Inward Dial
- Dirty Paper Coding
- Downlink
- Duplex
- Echo Cancellation
- Electromagnetic Radiation
- Electronic Switching System
- Emission Security
- Facsimile
- Feature Phone
- Fiber-Optic Service
- Forking Proxy Server
- Full Duplex
- General Switched Telephone Network
- General Telephone and Electronics Corporation
- Global Navigation Satellite System
- Great Firewall of China
- Guard Band
- Half Duplex
- Hard Handoff
- Hayes Smartmodem
- Hundred Call Seconds
- Hybrid Fiber-Coaxial Cable
- Interactive Voice Response
- International Telecommunication Union
- Internet Caller ID
- Internet Protocol Private Branch Exchange
- Internet Protocol Telephony
- Internet Telephony
- IP Centrex
- IP PBX
- Key Telephone System
- Leased Line
- Least Cost Routing
- Line Information Database
- Line Load Control
- Link Budget
- Local Number Portability
- Mean Opinion Score
- Microcell
- Minimum Point of Entry
- Mobile Assisted Handoff
- Mobile Centrex
- Mobile Identification Number
- Modulation
- Municipal Wi-Fi
- Narrowband
- Network Equipment-Building System
- Numbering Plan
- Open Networking Foundation
- Optical Local Exchange Carrier
- Over-the-Top Application
- Passive Optical Network
- Permanent Virtual Circuit
- Primary Rate Interface
- Pseudowire
- Quadrature Amplitude Modulation
- Radio Access Network
- Radio Frequency Over Glass
- Satellite Internet Access
- Shared Call Appearance
- Short Message Peer-to-Peer
- Spectrum Crunch
- Speed Dial
- Spread Spectrum
- Store and Forward
- Streaming Media
- Subscriber Identity Module Card
- Switched Line
- T1 Line
- Telecom Analytics
- Telecom Expense Management
- Telecommunications Equipment
- Telegraphy
- Telehealth
- Telematics
- Telemedicine
- Telephone Jack
- Telepresence
- TEMPEST Shielding
- Texting
- Transmission Tower
- Transmitter
- Tri-band
- Two-Way Communication
- Universal Integrated Circuit Card
- Universal Service Ordering Code
- Uplink
- Value-Added Service
- Virtual Call Center
- Virtual Network Operator
- Virtual Private Branch Exchange
- Voice Dial
- Voice Over Long-Term Evolution
- Voice Peering
- Wide Area Telephone Service
- Wideband Integrated Dispatch Enhanced Network
- Wire Stripper
- Wireless Backhaul
- Wireless Number Portability
