| dc.description.abstract | Nowadays, with the development of the next-generation network, IMS becomes very
important, and it will play a key role in the future All-IP infrastructure. But it is still in the
developing stage, and it will take time for all 3G mobile networks upgrade to 3GPP
networks. Therefore, the research project will study the interoperability solutions
between Open Source IMS and Open Source VoIP/SIP implementations. This project
is supported by auSystems and HiA.
OpenIMS (Open Source IMS) was developed by FOKUS (a Germany institution) in
December 2006. It is a free IMS enterprise solution. As it is so new, there are still
many doubts about using it. Therefore, it is important to evaluate it. auSystems and
HiA have already established a research testbed for Enterprise VoIP solutions. For us,
as a starting point, we extended the existing testbed with a new IMS sub-domain
based on the “Open Source IMS Core”. And then, Wireshark is used to trace the
signaling to validate if the functionality of each component of the OpenIMS is
conformant with the 3GPP R6 specification in TS 24.229 and TS 29.229.
After that we evaluated the performance of the OpenIMS as well. In this part, SIPp is
used as the testing tool to do experiments. According to the results, we evaluated the
performance of OpenIMS in the following aspects: the numbers of subscribers the
OpenIMS can handle; the reliability of OpenIMS; does it work simultaneously or stably;
how often does it response? We also discuss what client or devices Open IMS can
support.
In this project, the other important task is to find a possible interoperability between
OpenIMS and the existing SIP/VoIP enterprise solution. In order to implement the
challenge, we divided the problem into two parts:
Firstly, we solved the interpretability from the SIP clients to the IMS clients in a single
domain. In this step, we proposed a possible solution, designed the structure of
OpenIMS and implemented it.
The last challenge of the project is to researche the interconnect way of OpenIMS with
existing SIP/VoIP solutions from OpenIMS domain to two domains which contain
OpenIMS domain and non-OpenIMS enterprise domain. In addition, state-of-the-art of
SIP/VoIP solutions had been studied. We tried to implement the “client-based”
solution of interconnecting OpenIMS with existing SIP/VoIP. This solution was
proposed in [8]. | en |
