IP Multimedia Subsystem Open Source System (imsoss)  is the java opensource implementation of X-CSCF elements of the IP Multimedia Subsystem(IMS) as defined by 3GPP Technical Specs. The implementation of imsoss will be done using the jain-slee technology and would need jain-slee container  for deployment.

IMPORTANT The focus is to have the imsoss deployed on mobicents jain-slee server !!!

Architecture

All the needed X-CSCF elements of the IMS would be represented by the jain-slee server at the macro level, at the granular level each X-CSCF would be represented by some set of SBB's, jain-slee SIP/Diameter ResourceAdapters and jain-slee server. Let us have a look at the broader view of IMS from the one of the sun's presentation about the jain-slee tutorial, here it goes

                                                                                                                          IMS on jain-slee server

X-CSCF nodes represented in imsoss are deployable on specific IP at particular PORT, this makes the imsoss CSCF's as distributed and thus making it more flexible and extensible.

With this distributed architecture the imsoss X-CSCF's can be integrated with X-CSCF's from other vendor too.X-CSCF elements in imsoss are implemented as set of jain-slee Service Building Blocks (SBB's) components and require SIP/DIAMETER-RA, both SBB's and SIP-RA are run in jain-slee server.

So, X-CSCF = JAIN-SLEE+SIP/DIAMETER-RA+SBB's.

To form the complete IMS we need have the reference points which would be available(developed) at mobicents project, the list of reference points that are going to be implemented are stated here http://groups.google.com/group/mobicents-public/web/mobicents-jainslee-app-basicims?hl=en

References

1) http://www.3gpp.org/article/ims

2) jain-slee spec http://jcp.org/en/jsr/detail?id=240

3) SIP RFC http://www.ietf.org/rfc/rfc3261.txt

4) http://en.wikipedia.org/wiki/IP_Multimedia_Subsystem