IMS SIP addresses the needs of manufacturers developing 3GPP and WiMAX handsets and other mobile IPphones (Internet phones), datacards, mobile platforms and chipsets. A good 3GPP/IMS compliant software stack will support the key 3GPP authentication and security standards plus the required IETF SIP RFCs. IMS should be tested to be standards compliant and network interoperable using in-house IMS handset emulators and network simulators plus private access to live 3GPP networks. 

WiMAX standards call for similar, if not identical SIP features.  We expect that WiFi will also use many of the same voice enabling features that 3GPP and WiMAX have called out.

Desirable Features of an IMS SIP Stack:

A good IMS SIP stack has the following features:

  • Jointly developed with #1 Mobile Service Provider
  • Very small system memory size
  • Flexible, full-featured core
  • User Agent Client & Server
  • 3GPP/IMS Compliant
  • IETF Standards-based
  • OS independent
  • ANSI C for ease of portation

Applications where an IMS SIP SDK is appropriate:

IMS SIP is developed specifically for next generation applications:

  • 3G Smartphones
  • 3G Datacards
  • 3G PDAs
  • WiMAX Products
  • Telco/VoIP Gateways
  • ATA/Residential Gateways

IMS SIP should be tight and fast:

  • Support for methods, headers, and message processing is configurable to save memory.
  • Smallest configuration fits in less than 100KB.
  • Just-in-time parser avoids parsing headers not used by SIP stack or application.
  • Optimized handling of timers avoids high start/stop overhead.
  • Crafted parser eliminates typical parser-generator bloat.

IMS SIP should be easy to use:

  • Low-level API provides complete control over all SIP functions and message content.
  • API supports multiple independent services including multi-homing.
  • User can easily add special method and header processing.
  • SDP parser is separate from SIP parser for use in other SDP applications.

IMS SIP should be easily ported to any environment:

  • Portable to any memory model, including flat, heap, pool-based, and mbuf or zbuf.
  • Object-oriented API supports direct function-call interface, inter-task and inter-cpu messaging.
  • Highly scalable – no built-in limits other than those required by the system itself.

IMS SIP provides a broad development and debugging environment:

  • Sample applications to demonstrate use of the APIs.
  • Initial ports include Linux, uCLinux, VxWorks, Nucleus, Windows and TsRITE OSes.
  • Sample make files and imake scripts.
  • Debugging & auditing features allow compile-time & run-time details for logging of messages & events.

Compliance Testing:

  • Exclusive in-house 3GPP Handset emulator and Network Simulator test platforms.
  • Private access to 3GPP networks allow extensive live testing.
  • Rigorously tested against IETF & PROTOS torture test suites and 3rd party equipment.
  • Successful SIPit Interoperable testing against multiple vendors equipment.