SIP Server Platform

a Software Development Kit

The SIP Server Platform is a Software Development Kit (SDK) that provides all the necessary building blocks required to develop SIP Server applications. Using the SIP Server Platform, developers can easily implement a wide variety of SIP server applications, such as IMS servers or Unified Communications applications. The SIP Server Platform is part of a family of IMS and SIP products and services, such as the IMS Developer’s Suite and IMS SIP Server solutions.

Formerly Radvision SIP Server Platform or SIP Server Framework

Key highlights

Shortened development cycles

You focus on the application while the platform focuses on the infrastructure


The product provides assured interoperability with market-leading products with periodic interoperability testing

High performance

Horizontal scaling achieved by higher transaction per second performance


Ability to control everything, down to the bits and bytes

For developers of

  • IMS Application servers: Presence, event notifications, call control, billing
  • Interworking function
  • P/I/S-CSCF
  • BGCF
  • SCIM (Service capability Interaction Manager)
  • Security gateway
  • SBC (Session Border Controller)

Did you know?

The Presence and Events module can be used for applications other than presence, such as control systems for trains and transportation.


The SIP Server Platform architecture is composed of modules suitable for developing many SIP server applications, such as SIP proxy or SIP B2BUA.

Key highlights

OS Abstraction Layer

This layer implements the decoupling from the OS, providing easy porting between operating systems, and hiding a portion of OS API complexity.


The IMS SIP stack implements the SIP messaging layer of the SIP server. The SIP stack is the first commercial IMS SIP-compliant stack.

SIP Server Core

This layer implements the message dispatching and some additional core functionalities, such as configuration management.

Presence & Event Server

Implements Presence server with complete presence event package and WINFO. This module is also the framework for every application based on diverse event packages.


The Back-to-Back module provides the engine and implementation for sophisticated call-control features and general SIP B2BUA functionality. The B2B has a unique modular architecture that can be used for developing sophisticated SIP applications. For additional information, please visit the Back to Back Application framework information page.

Proxy & Redirect

Implements complete SIP Proxy and redirect server supporting message routing and forking.


Implements complete SIP Registrar to handle SIP registrations

Security Component

In-memory database used to store authentication-related information.

Location Component

In-memory database storing the location (IP address) of local SIP terminals.

Reference Implementation

Provides the examples of SIP Server Platform API usage, illustrating how to program several applications, such as a presence server.


  • Source code with highly-flexible API
    for maximum control
  • Mix and match modular architecture
  • Comprehensive documentation and samples for rapid kick-start
  • Comprehensive up-to-date standards conformance—IETF, 3GPP,TISPAN
  • Proven robust performance and worldwide interoperability
  • Multiple OS support and flexible OS portability
  • Market-leading performance and scalability
  • Low footprint
  • High maintainability and professional customer support
Separate control on each call-leg for creating sophisticated services
Message routing:
  • Support for proprietary SIP responses/headers
  • Parallel and serial message forking
  • Loose and strict routing
  • Loop detection
Presence and event notifications:
  • Support for generic event packages
  • Partial Presence
  • Support for WINFO


The SIP Server platform is continuously upgraded to support the latest IETF SIP and IMS SIP standards. For more information please refer to the product specifications.

The SIP Server Platform is continuously tested at all major inter-op events.

Common Core
OS Abstraction Layer (a.k.a. common core) makes the SIP Server Platform future-proof. When you decide to change or upgrade the underlying operating system, your previous investment is protect.

Softil SIP Server Solution Data Sheet