Building Telephony Systems with OpenSER
Server Operating as a SIP Proxy
Server Operating as a SIP Redirect
The SIP Protocol and the OSI Model
The VoIP Provider "Big Picture"
Where You Can Find More Information
What is the SIP Express Router?
What Software to Use, SER or OpenSER?
Differences between Strict Routing and Loose Routing
OpenSER Standard Configuration
Analyzing the Standard Configuration
Using the Standard Configuration
Adding Authentication with MySQL
The REGISTER Authentication Sequence
The Functions check_to() and check_from()
Handling CANCEL requests and retransmissions
Full Script with All the Resources Above
Building the User Portal with SerMyAdmin
Lab—Using Asterisk as a PSTN Gateway
Blacklists and "473/Filtered Destination" messages
Inspecting the Configuration File
Lab—Testing the Call Forward Feature
Solving the SIP NAT Traversal Challenge
Handling REGISTER Requests behind NAT
Handling INVITE Messages behind NAT
MediaProxy Installation and Configuration
Lab Using MediaProxy for NAT Traversal
OpenSER Accounting and Billing
Installation of FreeRADIUS and CDRTool
Packet Capture and Trace Tools
Migration from 1.2.2 to 1.2.3 and 1.3.1
Migrating the Script from Chapter 10 to openser 1.3.1