In 2005, the OpenSER project was created by Bogdan-Andrei Lancu of Voice System, and it quickly became recognised as one of the most proficient, powerful, and well known of all open-source SIP proxies. In 2008, due to trademark issues regarding the OpenSER name, Voice System renamed OpenSER as OpenSIPS. OpenSIPS is simply an acronym of Open Session Initiation Protocol Server, which is an open source implementation of a GPLed SIP server. Open source simply means that a product is completely accessible from a design and implementation perspective, and can be distributed free of charge.
The philosophy behind open source development is collaboration, cooperation and community to further enhance the product. This open source roots of OpenSIPS and the collective effort of the worldwide community of users led to a 25% speed increase of database operations and load balancing capabilities, as well as 11 new modules within a 6 month timeframe. The true benefit of OpenSIPS is the huge throughput that is achievable using OpenSIPS, coupled with a high level of reliability, that puts the solution in the carrier-grade or enterprise class.
OpenSIPS includes application level functionality and has an extremely flexible and customisable routing engine that allows for the unification of voice, IM, and Video due to it’s modular design, which makes it hugely efficient. OpenSIPS is highly flexible, has an application interface and modules for effective application building, and extremely high scalability that allows up to thousands of calls per second of transitional throughput. Due to these extremely valuable features, OpenSIPS is used by telecommunication operators, enterprises, and network operators. OpenSIPS relates only to signalling, and is a multi-purpose, multi-functional SIP server that can be used as:
- A switch
- A router
- A registrar
- An application server
- A gateway
- A load-balancer
Whilst other solutions, such as Asterisk, are able to connect with the PSTN (Public Switched Telephone Network) via telephony cards, this is not possible with OpenSIPS. Instead, OpenSIPS has to connect through a SIP gateway to connect to the PSTN.
The OpenSIPS Vision
The OpenSIPS vision is described as ‘consolidated diversity’ in the way that OpenSIPS is open sourced not only as a licence, but also in respect of the policy regarding the contributions of the community. The diversity element of the vision comes from the volume of people involved in the progression and development of this project, and also the complexity and feature rich nature of OpenSIPS itself. The consolidation element of the vision comes from the fact that all of the contributions from the community need to be consolidated by the project management to maintain a high level of reliability and stability.