About -> Features
Some of the features that OpenSIPS brings:
- robust and performant SIP (RFC3261) Registrar server, Location server, Proxy server and Redirect server
- small footprint - the binary file is small size, functionality can be stripped/added via modules
- plug&play module interface - ability to add new extensions, without touching the core, therefore assuring a great stability of core components
- stateless and transactional statefull SIP Proxy processing
- support for UDP/TCP/TLS/SCTP transport layers
- IPv4 and IPv6
- support for SRV and NAPTR DNS
- SRV DNS failover
- IP Blacklists
- multi-homed (mhomed) and multi-domain support
- flexible and powerful scripting language for routing logic
- variables support in script - script variables, pseudo-variables (access to the SIP messages), AVPs (values persistent per SIP transactions)
- management interface via FIFO file and unix sockets
- authentication, authorization and accounting (AAA) via database (MySQL, Postgress, text files), RADIUS and DIAMETER
- digest and IP authentication
- Presence Agent support (many additional integration features)
- XCAP support for Presence Agent
- CPL - Call Processing Language (RFC3880)
- SNMP - interface to Simple Network Management Protocol
- management interface (for external integration) via FIFO file, XMLRPC or Datagram (UDP or unixsockets)
- NAT traversal support for SIP and RTP traffic
- ENUM support
- PERL Programming Interface - embed your extensions written in Perl
- Java SIP Servlet Application Interface - write Java SIP Servlets to extent your VoIP services and integrate with web services
- load balancing with failover
- least cost routing
- support for replication - REGISTER offer new functions for replicating client information (real source and received socket).
- logging capabilities - can log custom messages including any header or pseudo-variable and parts of SIP message structure.
- modular architecture - plug-and-play module interface to extend the server's functionality
- gateway to sms (AT based)
- multiple database backends - MySQL, PostgreSQL, Oracle, Berkeley, flat files and other database types which have unixodbc drivers
- straightforward interconnection with PSTN gateways
- dialog support (call monitoring, call termination from proxy side, call profiling)
- XMPP gateway-ing ( transparent server-to-server translation)
- impressive extension repository - over 70 modules are included in OpenSIPS repository
Scalability:
- OpenSIPS can run on embedded systems, with limited resources - the performances can be up to hundreds of call setups per second
- used a load balancer in stateless mode, OpenSIPS can handle over 5000 call setups per second
- on systems with 4GB memory, OpenSIPS can serve a population over 300 000 online subscribers
- system can easily scale by adding more OpenSIPS servers
- OpenSIPS can be used in geographic distributed VoIP platforms
- straightforward failover and redundancy