| A | B |
|---|
| OTDR | Optical Time Domain Reflectometer |
| PAP | Password Authentication Protocol |
| PAT | Port Address Translation |
| PC | Personal Computer |
| PKI | Public Key Infrastructure |
| PoE | Power over Ethernet |
| POP3 | Post Office Protocol version 3 |
| POTS | Plain Old Telephone System |
| PPP | Point-to-Point Protocol |
| PPPoE | Point-to-Point Protocol over Ethernet |
| PPTP | Point-to-Point Tunneling Protocol |
| PRI | Primary Rate Interface |
| PSTN | Public Switched Telephone Network |
| PVC | Permanent Virtual Circuit |
| QoS | Quality of Service |
| RADIUS | Remote Authentication Dial-In User Service |
| RARP | Reverse Address Resolution Protocol |
| RAS | Remote Access Service |
| RDP | Remote Desktop Protocol |
| RFI | Radio Frequency Interface |
