What is PSTN?
PSTN is a global telephone system that providing the telephone services to local and corporate or business users. PSTN is a collection of different PSTN switches and other device of different ISPs that connects residential and business users. You can also connect yourdistant office’s PBXand telephones with PSTN network. PSTN is running open standard protocols for control and transparent communications between circuits, switches and phones. PSTN switches often connect business PBX’s and these switches are locates at Telco/ISP central offices.
Between two PBX over the PSTN E&M signaling is used while within the PSTN there are many signaling like CCS, BRI, PRI, ISDN etc.
The PSTN provides a suite of services in addition to call setup and routing:
- Voice mail
- Database services
- Interactive voice response (IVR)
- Automatic call distribution (ACD)