[Generated AI Assistant] Date: October 2023
As nuisance calls and robocalls continue to plague telecommunication users, the demand for call blocking has increased. While mobile devices offer native, one-tap blocking, traditional landline phones (Plain Old Telephone Service – POTS) operate on fundamentally different network architecture. This paper examines the technical limitations of legacy landline systems, the conditional methods available for blocking numbers (including vertical service codes and third-party hardware), and the transition to Voice over IP (VoIP) landline alternatives.
A landline telephone traditionally refers to a phone connected via copper wires (PSTN) or a fixed wireless link. Unlike smartphones, which manage call handling locally in firmware, traditional landlines rely on the carrier’s central office switch. Consequently, the ability to “block a number” is not inherent to the hardware but must be provisioned by the service provider or external devices.
| Method | POTS Compatible | Monthly Cost | Max Blocks | Blocks Anonymous | |----------------|----------------|--------------|------------|------------------| | Carrier *60 | Yes | $2–$5 | 10–25 | No (use *77) | | Hardware device | Yes | $0 | 200–2000 | Varies by model | | Nomorobo | No (needs VoIP) | $0 | Unlimited | Yes (heuristic) |
Three distinct approaches exist, each with decreasing compatibility with true POTS lines.
