OSIMS - An Open Source IMS experimentation platform

OSIMS is the Patras Open Source IMS testbed

About IMS

IMS widely known as IP Multimedia Subsystem is an IP multimedia and telephony core network that is defined by 3GPP and 3GPP2 standards and organizations based on IETF Internet protocols. IMS is a set of specifications that describes the Next Generation Networking (NGN) architecture for implementing IP based telephony and multimedia services. It defines a complete architecture and framework that enables the integration of voice, video, data and mobile network technology over an IP-based infrastructure. IMS is access independent as it supports IP to IP session over wireline IP, 802.11, 802.15, CDMA, packet data along with GSM/EDGE/UMTS and other packet data applications. Before going through the details lets have a look into the history of IMS.


Our IMS testbed is depicted in the following figure. The core of our IMS system is based on the Open Source IMS core of OpenIMS found at http://www.openimscore.org/. This enabled us to create Next Generation Network core elements within R&D and IMS interested parties. OpenIMS enabled us the development of IMS services and the trial of concepts around core IMS elements that are based upon highly configurable and extendable software. The Open Source IMS Core consists of Call Session Control Functions (CSCFs), the central routing elements for any IMS signaling, and a Home Subscriber Server (HSS) to manage user profiles and associated routing rules. The central components of the Open Source IMS Core project are the Open IMS CSCFs (Proxy, Interrogating, and Serving). But since even basic signaling routing functionality for IMS requires information look-up in a HSS, normal usage of such a core IMS network is not possible without it, therefore a simple HSS is also part of the Open Source IMS Core project. OSIMS is a unique open and vendor-independent NGN/IMS test environment that can be used as a testbed by academic and industrial institutions for early prototyping of new NGN/IMS related components, protocols, and applications, as well as for testing and benchmarking of components. Also, the interconnection to other IMS testbeds worldwide is currently in process in order to allow the experience of IMS concepts and IMS services to be shared with partners.


Why an IMS testbed?

Before you release your hardware/software you need to test your product in real world like environment and by running of systematic step-by-step tests. The IMS testbed constitutes such an environment, where various experiments can be run. we are developing systematic tests to test functionality, interoperability and conformance of IMS components, including definition of test purposes, choice of the method, test case specification, execution of tests and evaluation of results. Another group of test comprises performance tests and benchmarking. The actual work concentrates on signaling paths in IMS: SIP and DIAMETER messages, with end user simulation and measurements of response time, rate (throughput) in TPS (transactions pro sec) and resource utilization. Different kinds of tests are possible:

  • benchmarking – for comparison
  • load/stress – how systems perform under load
  • capacity testing – max load the system can handle before failing
  • scalability testing – to plan capacity improvements
  • interoperability testing – to verify the compatibility and conformance

Core components

OSIMS consists of the following services:

  • A Home Subscribe Server (HSS)
  • A Serving-CSCF Module (scscf)
  • A Proxy-CSCF Module (pcscf)
  • An Interrogating-CSCF Module (icscf)
  • An OpenSIPS server
  • A presence server based on OpenSIPS
  • An XDMS service for storing directory information*
  • An Asterisk server for connection to other phone services*
  • A presence server based on OpenSIPS
  • A media server, streaming video channels
  • A webrtc2SIP gateway service for enabling connection of HTML5/webrtc clients
  • All services connected on an OpenFlow switch (OpenVSwitch)

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Features of OSIMS

OSIMS testbed has some following unique features to ease experimentation on an IMS testbed:

  • Simple or no management. Just create accounts and verify your IMS clients against different IMS features and messages.
  • Accessible via public IPs and DNS names. There is no need for a special network setup.
  • Explore media applications with our build in media streaming server. IMS channels are already there.
  • Support fo Presence and XDMS scenarios
  • Create complex scenarios you can get full-access to the testbed at super user level and add/modify or delete anything you want. Reset the testbed and start all over!
  • Easy logging of all core components
  • With our phones more scenarios are available like: Calls between PSTN terminals (national/international), IP Phones - PSTN calls, GSM –PSTN calls, GSM – IP calls
  • Integration with OpenFlow switches for QA testing of IMS policy functions
  • Integration with more resources from our other testbeds like CloudVille or our interconnection with PlanetLab if your testing demands more computing power
  • Easy support of the entire life-cycle of your experiment with our tools, FSToolkit, FCI.

Together with the ability of getting full root ssh access to the testbed, you get the most flexibility of the testbed. In case you mess up with the testbed you can reset and start all over with a fresh installation!

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Services we offer

  •     Instantiation of the OSIMS testbed
    We equip your organization with a full IMS test environment to allow you run your own IMS and NGN related test scenarios.
  •     Interconnection of testbeds
    Your test environment can be connected to the OSIMS testbed to test advanced deployment scenarios.
  •     Conformance and Interoperability Testing
    Is your component conforming with the latest specifications? Does it work together with our partner components? We’ll let you know.
  •     Tutorials
    We offer different coaching and tutorial sessions to let you benefit from our knowledge.
  •     Consulting / Studies
    Is there something about IMS and NGNs you need to know in detail? We’ll provide you with scientific studies and consulting.
  •     Comprehensive Testbed Projects
    Being a partner in many international projects in industry and academia we gathered considerable experience in terms of project management and long term project contributions.

Start Experimentation on OSIMS today!

Schedule your experiment and reserve the testbed

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OSIMS tutorials!

OSIMS/Experimentation tutorials

Check some video tutorials that we have put in place! Learn in a few minutes how to access and create experiments involving our Open Source IMS platform for experimentation! View:

  • Reserve the testbed and experiment in minutes
  • Create Subscribers with both FSToolkit and FCI
  • Access full testbed services
  • Learn how to test IMS clients
  • Watch compatibility of new technologies (i.e. WebRTC)
  • and more...

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