Installation guide

AP-IP120 IP Phone Installation Guide Version 1.0
AddPac Technology Proprietary & Documentation
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VoIP Setup– PSTN Prefix
When user wants to access the FXO interface for PSTN backup, this prefix number is used as PSTN
access code. Additionally, AP-IP120 IP phone supports the PSTN back-up service when VoIP service
is impossible due to network failure or VoIP call service is interrupted by an accident.
(Figure 4-34) PSTN Prefix Menu Option
[Table 4-23] Description of PSTN Menu Option
Menu Option Description
PSTN prefix number is an access code for PSTN FXO
interface, default value is #.