Development -> Planning -> OpenSIPS 3.5 Planning

OpenSIPS 3.5 philosophy

Bits and pieces of the IMS (IP Multimedia Subsystem) topic were part of the previous OpenSIPS release, but 3.5 aims to fully focus on the IMS part. Considering the traction and need of IMS solutions, we see the implementation of a consistent and large IMS support in OpenSIPS as a mandatory step in order to answer to the needs of the industry.

The IMS topic is a large one, transcending the SIP protocol and the scope of OpenSIPS. So, the OpenSIPS 3.5 will identify and work out the parts of the IMS ecosystem which are based or related to SIP, of course.

Strategy

As said, the IMS topic is a very large and complex one. Secondly, one goal here is to design and implement an IMS support that is truly able to provide solutions for the industry. So, a quite extensive stage of exploring, understanding and designing on the IMS ecosystem will be required in a first stage.
In order to guarantee a successful approach, multiple parties must be involved in this stage. Parties coming from the developers side, from the integrator side and, of course, from the solution provider side - shortly, the parties actually using (or planning to use) IMS - must be involved here and contribute to drafting and producing a realistic IMS support to answer the industry needs.

The IMS Working Group

To facilitate this exchange of information and ideas between all the IMS-interested parties, we considered adding a new mechanism into the OpenSIPS project, namely the Working Groups - a gathering of people to focus and discuss on a specific topic.

The first to be created is the IMS OpenSIPS Working Group (IMS OWG) - the resource here is a dedicated mailing list where people with interest in IMS may join and contribute to the drafting, designing and implementation of the IMS support in OpenSIPS. Of course, anyone is welcome, the list is a self-subscription list. The group will share a GitHUB WIKI resources also.

The IMS OpenSIPS WG will shortly start its activity by building a set of requirements for the IMS support in OpenSIPS.

Starting point

As said, the IMS topic is a vast one and the IMS OpenSIPS Working Group will have the task of exploring and identifying the requirements for OpenSIPS 3.5. Still, we need a starting point, and here we consider for sure the Control Layer, mainly the CSCF with all its components. Again, we are not drawing any borders / limits, just considering some starting points for further discussions.

Getting a bit in details, we have a starting wish list for the IMS work, but the actual points to be targeted by the OpenSIPS 3.5 implementation will take shape (and get published) once the IMS OpenSIPS Working Group will produce its requirements.

Some points

• DIAMETER enhancement to be able to read and write raw data into AVPs
• DIAMETER full server side support, to be able to receive and handle at any time an incoming request
• Digest AKA V1 V2 support
• IPSec support for SIP traffic
• IMS related presence events (like "reg")
• HTTP 2.0 support

Conclusions

A fully functional OpenSIPS IMS solution, seamlessly integrated with the Docker Open5GS Core Network, has been successfully developed and delivered as part of a Community Edition project.