The SIP proxy can operate in the SIP redirect mode. In this mode the SIP server is very scalable, because it doesn't keep the state of transactions. Just after the initial INVITE, it replies to the UAC with a "302 Moved Temporarily" and gets off the SIP dialog. In this mode a SIP proxy, even with very few resources, can forward millions of calls per hour. It is normally used when you need high scalability, but don't need to bill the calls.
Building Telephony Systems with OpenSER
Building Telephony Systems with OpenSER
Overview of this book
Table of Contents (18 chapters)
Building Telephony Systems with OpenSER
Credits
About the Author
About the Reviewers
Preface
Free Chapter
Introduction to SIP
The SIP Express Router
OpenSER Installation
OpenSER Standard Configuration
Adding Authentication with MySQL
Building the User Portal with SerMyAdmin
Connectivity to the PSTN
Call Forward and Voice Mail
SIP NAT Traversal
OpenSER Accounting and Billing
Troubleshooting Tools
After Words
Index
Customer Reviews