H.323 Protocol Stack

An award-winning Toolkit

The award-winning, Softil H.323 Protocol Toolkit implements all mandatory H.323 features and offers the most extensive implementation of optional capabilities.

The current Softil release is ITU-T H.323 version 7 compliant, supports the latest standards and is fully backward compatible.

Formerly Radvision H.323 Protocol ToolKit, Radvision H.323 Protocol Stack or H.323 SDK


Most widely deployed H.323 solution

Large customer base, with hundreds of different products deployed today

Rich API set

Support for the latest H.323 standards and technologies, through flexible and varied APIs

The H.323 stack can be used to develop:

  • MCUs
  • Gateways
  • Softswitches
  • IADs
  • IP phones
  • VoIP-enabled chipsets
  • Room systems
  • IP-PBXs
  • Session Border Controllers (SBCs)


The H.323 Stack is a modular solution, enabling the development of virtually any type of H.323 device. It includes an optional set of add-on modules, including the H.460.17-19 Firewall/NAT Traversal, H.450 Supplementary Services and H.235 Security.

The H.323 Stack comes with

  • Full source code
  • Complete source code sample application
  • Full documentation, programmer’s guide and reference guide
  • Porting guide (for unsupported operating systems)
  • Training
  • Version upgrades
  • Professional customer support
  • Turnkey solutions (upon request)
  • Porting services (upon request)
The H.323 stack supports all of the latest standards required to build VoIP solutions. Refer to the product datasheet for more information.


IMS (IP Multimedia Subsystem) was developed by 3GPP and it is a SIP-based network that serves as the infrastructure for service, call, and session control in advanced mobile networks. IMS is deployed in 3G/4G and LTE networks, as well as many other types of networks, such as fixed telephony, packet cable, and more.

H.323 Protocol Toolkit Data Sheet