Building Telephony Systems with OpenSIPS - Second Edition

Chapter 7. Dialplan and Routing

In the previous chapter, you learned how to use OpenSIPS to route calls between SIP users, provision such users, and authenticate them using a database backend. However, you still cannot send calls to ordinary phones because you are not connected to the Public Switched Telephone Network (PSTN). The challenge now is to route calls from and to the PSTN, as shown in the following figure:

This PSTN interconnection comes with special needs such as advanced number matching and manipulation (dialplans), IP-based authentication, and dynamic routing (based on the prefix, priority, location, or time of day).

Unless you have ...