Complete Communications Engineering

VOCAL’s Session Initiation Protocol (SIP) Software Library implements

Session Initiation Protocol - SIP Protocol
SIP is used to establish and terminate mobile, VoIP, voice and video conferencing, and multimedia sessions

RFC 3261 with full support for SIP client and server applications. Our cross platform SIP stack can be combined with our comprehensive software library of algorithms and protocols to implement VoIP, mobile (VoNR, VoLTE, Dialer), voice and video conferencing, Radio over IP (RoIP), Modem and Fax over IP, Serial over IP and multimedia applications. Contact us to discuss your specific SIP application requirements. Custom designs are also available.

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VOCAL’s server, cloud and embedded libraries include a complete range of ETSI / ITU / IEEE compliant algorithms, in addition to many other standard and proprietary algorithms. Our SIP software is optimized for execution on all major general purpose and DSP architectures (Intel, AMD, ARM, Texas Instruments (TI), Analog Devices (ADI), MIPS, etc.) and portable enough to run on just about anything. The software libraries are modular and can be executed as a single task under a variety of operating systems or standalone with its own microkernel or our small network stack.

Session Initiation Protocol

Session Initiation Protocol is an application-layer control protocol that can establish, modify, and terminate multimedia sessions (conferences)  such as Internet telephony calls using Voice over IP (VoIP).  SIP supports user applications that require the creation and management of a session, where a session  is considered an exchange of data between an association of participants. The implementation of these applications is complicated  by the practices of participants: users may move between endpoints, they may be addressable by multiple names, and they may communicate  in several different media – sometimes simultaneously.

Session Initiation Protocol can invite participants to already existing sessions, such as multicast conferences. Numerous protocols have been authored that carry various forms of real-time multimedia session data such as voice, video, or  text messages. SIP works in concert with these protocols by enabling Internet endpoints  (called user agents) to discover one another and to agree on a characterization of a session they would like to share. Media can be added to (and removed from) an existing session.

Session Initiation Protocol transparently supports name mapping and redirection services for enhanced personal mobility. To locate prospective session participants, and other functions, SIP enables the creation of an infrastructure of  network hosts (called proxy servers) to which user agents can send registrations, invitations to sessions, and other requests. It is an agile, general-purpose tool for creating, modifying, and terminating sessions that works independently of underlying  transport protocols and without dependency on the type of session that is being established.

Session Initiation Protocol supports:

Session Initiation Protocol provides a suite of security services,  which include denial-of-service prevention, authentication (both user to user and proxy to user), integrity protection, and  encryption and privacy services.

SIP is used in conjunction with other protocols to provide complete services  to the end user including:

SIP Protocol Library Features


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supported platforms

VOCAL’s optimized software is available for the following platforms. Please contact us for specific Session Initiation Protocol supported platforms.

ProcessorsOperating Systems
  • Texas Instruments – C6xx (TMS320C62x, TMS320C64x, TMS320C645x, TMS320C66x, TMS320C67x), DaVinci, OMAP, C5xx (TMS320C54x, TMS320C55x)
  • Analog Devices – Blackfin, ADSP-21xx, TigerSHARC, SHARC
  • PowerPC, PowerQUICC
  • MIPS – MIPS32, MIPS64, MIPS4Kc
  • ARM – ARM7, ARM9, ARM9E, ARM10E, ARM11, StrongARM, ARMCortex-A8/A9/A15/A3x/A5x/A7x, Cortex-M3/M4/M7/M33
  • Intel / AMD – x86, x64 (both 32 and 64 bit modes)
  • Linux, uClinux, BSD, Unix
  • Microsoft Windows ACM / RTC / CE / Mobile
  • Apple iOS / iPhone / iPad & MacOS
  • eCOS / eCOSPro
  • Google Android
  • Green Hills Integrity
  • Micrium μCOS
  • Symbian
  • Wind River VxWorks