P
- P2P (Peer-to-Peer)
- PABX (Private Automatic Branch Exchange)
- Packet Delay
- Packet Error Rate (PER)
- Packet Filtering
- Packet Loss
- Packet Switching
- Paging
- Paging System
- Parallel Redundancy Protocol (PRP)
- PBX (Private Branch Exchange)
- Phantom Power
- Physical Layer (Layer 1)
- Pilot Number
- PIN (Personal Identification Number)
- PoE (Power over Ethernet)
- Port
- Port Forwarding
- Port Mirroring
- Postpaid Service
- POTS (Plain Old Telephone Service)
- Power Fail Transfer
- Power Over Ethernet Plus (PoE+)
- Predictive Dialer
- Prepaid Service
- Presence
- Presence Information Data Format (PIDF)
- PRI (Primary Rate Interface)
- Primary Rate Interface (PRI)
- Private Cloud
- Private Line
- Programmable Logic Controller (PLC)
- Protocol
- Protocol Converter
- Provisioning
- Provisioning Server
- Proxy Call Session Control Function (P-CSCF)
- Proxy Server
- PSTN (Public Switched Telephone Network)
- Public Cloud
- Public Key Infrastructure (PKI)
- Public Switched Telephone Network (PSTN)
- Pulse Code Modulation (PCM)
- Push Notification
- Push Notification Service (PNS)
- Push-to-Talk (PTT)
- Push-to-Talk over Cellular (PoC)
