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SIP Operation Manual
Example for 2S2O gateway:
P1-P2 is FXS interfaces and can be directly connected to a telephone set for direct calls. P3-P4 is
FXO interfaces and can be connected to a PSTN to serve as a bridge between the PSTN and
other VoIP telephones. The system also allows a call to be made from a traditional telephone line
to connect with a gateway user.
Integrating the 2S2O with PBX
P1-P2 is FXS interfaces and can be connected to a PBX CO or an analog telephone; P3-P4 is
FXO interfaces and can be connected to a PSTN to act as a bridge between the PSTN and other
VoIP telephones. The system also allows a call to be made from a traditional telephone line to
connect with a gateway user.
