iptel.org SIP Express Router (ser)

1. Introduction

   SIP Express Router (SER) is an industrial-strength, free VoIP server
   based on the session initiation protocol (SIP RFC2543-bis).  It is
   engineered to power IP telephony infrastructures up to large scale. The
   server keeps track of users, sets up VoIP sessions, relays instant
   messages and creates space for new plug-in applications. Its proven
   interoperability guarantees seamless integration with components from
   other vendors, eliminating the risk of a single-vendor trap. It has
   successfully participated in various interoperability tests in which it
   worked with the products of other leading SIP vendors.

   The SIP Express Router enables a flexible plug-in model for new
   applications: Third parties can easily link their plug-ins with the
   server code and provide thereby advanced and customized services.  

   Its performance and robustness allows it to serve millions of users and
   accommodate needs of very large operators. With a $3000 dual-CPU, the SIP
   Express Router is able to power IP telephony services in an area as large
   as the Bay Area during peak hours. Even on an IPAQ PDA, the server
   withstands 150 calls per second (CPS)! The server has been powering our
   iptel.org free SIP site withstanding heavy daily load that is further
   increasing with the popularity of Microsoft's Messenger.  

   The SIP Express Router is extremely configurable to allow the creation of
   various routing and admission policies as well as setting up new and
   customized services. Its configurability allows it to serve many roles:
   network security barrier, application server, or PSTN gateway guard for

2. Feature List

   See http://www.iptel.org/ser/features for an updated feature list.
   Note that as features easily are added as modules, changes can
   occur quickly.

   Most of SER features are implemented as plug-in modules. See
   http://www.iptel.org/views/tableofmodules for a list of modules 
   available in SER distribution.

3. About iptel.org

   See http://www.iptel.org/ser_history for the story of SER and iptel.org.

4. Obtaining Help

   We offer best-effort free support for ser. "best-effort" means 
   that we try to solve your problems via email as soon as we can, 
   subject to available manpower. 

   To receive feedback to your inquiries, we recommend you to subscribe to
   the serusers mailing list and post your queries there. This mailing list
   is set up for mutual help by the community of ser users and developers.
   To participate in the mailing list, subscribe at the following web


   Send your questions to 

5. More Information

   Most up-to-date information is always available at our website,

   Particularly, it includes:

      o  administrator's guide
      o  installation guidelines (INSTALL)
      o  download links
      o  list of known issues (ISSUES)
      o  etc.