AG Projects launches its SIP Presence system

AG Projects launches its SIP Presence system based on SIP SIMPLE standards.

AG Projects has launched a set of Open Source software components needed for the implementation of scalable Presence services based on SIP SIMPLE suite of protocols. The software is available at while the free SIP service with Presence features is provided at


SIP SIMPLE is a set of technologies standardized by the Internet Engineering Task Force (IETF). Its goal is to enable Presence applications by using the popular SIP protocol, which has been embedded in many hardware devices and software solutions.

A Presence system allows for publication of end-user information and subscription to the published information based on a policy controlled by the end-users. Being designed as an asynchronous mechanism, Presence provides real-time subsequent notifications whenever the publisher reports a change.

A typical presence application is the publication of online/offline indication of someone’s SIP devices. Many proprietary or standard based Interactive Messaging applications used on millions of today’s desktop computers illustrate this also.

The real power of the Presence concept is that one can publish any kind of relevant information that can be retrieved from an external system and translated into real time notifications by using SIP Protocol. Any standard SIP SIMPLE devices can be used for subscribing to this information using the Subscribe method. One can publish stock market information, warehouse inventory status and other relevant information as it changes in real time only to qualified recipients, something that web 2.0 technologies cannot provide in a standard way.

By using SIP protocol also for Presence, it is finally possible to combine all relevant real-time communication possibilities that can be offered over the Internet like voice, video, IM and Presence into one single end-user application.

SIP simple Presence can be used for generating paid services with per event charges, much like SMS is used today to subscribe to various premium value services. By being integrated with such a reach communication medium like SIP including voice video and IM, Presence based on SIP SIMPLE provides the missing link between communication web databases and business events.

Open Source SIP SIMPLE solutions

To build such a Presence system and scale it up to the size of the SIP infrastructures we commonly see today (tens of thousands to millions of subscribers) one needs to plan the addition of new components to their SIP infrastructure. These components are:

  • SIP Presence agent responsible for publication and notifications of events using SIP protocol
  • Presence policy server, responsible for the validation of subscription requested by the publisher
  • Presence gateway, responsible for translating information retrieved from an external system and its subsequent changes into Presence information
  • SIP SIMPLE end user devices, used for subscription and publication of events

Such system can be built today by using Open Source software. AG Projects developed a set of such software components and supports the development of  popular SIP software solution that can be used to implement a SIP Presence infrastructure.

The software’s source code and system setup documentation is available on the project web sites.

Commercial products based on SIP SIMPLE open source components

AG Projects provides its SIP Presence solution as part of its turnkey platforms; Multimedia Service Platform for up to 30,000 subscribers and SIP Thor, which can scale up to millions of subscribers in a geographic distributed fashion.

About AG Projects

AG Projects is an Open Source software vendor established in 2002 specialized in serving companies like cable operators and Internet service providers. We provide simple solutions for their complex problems.

AG Projects focus is the delivery and support of SIP infrastructure based on OpenSER SIP Proxy/Registrar/Presence server and related projects that complements xDSL, fiber and cable networks. The delivery includes the analysis of requirements, tailoring of our standard solutions to meet the requirements, project management, implementation and after sales training and support activities.

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