TekSIP is a SIP communication solution designed for Windows operating systems. Its primary function is to act as a SIP Registrar/Proxy, providing efficient connectivity and communication capabilities for organizations.

The software supports Network Address Translation (NAT) traversal, Universal Plug and Play (UPnP), and ENUM to simplify and streamline operations. It provides detailed technical information about NAT traversal in Readme.txt. Additionally, TekSIP allows you to select the IP address to be listened on and alternative routes for outgoing calls, to enhance convenience and flexibility.
TekSIP features a presence server that is SIP/SIMPLE based, along with an option to log session details and errors in a log file. It also supports Remote Authentication Dial-In User Service (RADIUS) Authentication (RFC 2865) and RADIUS Accounting (RFC 2866). The software provides an option to act as a Back-to-Back User Agent (B2BUA) in response to incoming 3xx SIP responses. If the RTP proxy is enabled, TekSIP can act as an RTP proxy and record audio streams.
The software can register to upstream SIP servers to receive incoming calls and monitors failed registration and call attempts from suspicious endpoints, thus blacklisting them. TekSIP Manager allows you to monitor blacklisted endpoints and remove them from quarantine if required. Moreover, it also allows you to ban specific user agents.
Running as a Windows service, TekSIP is fully equipped to support auto-provisioning of IP phones based on SUBSCRIBE / NOTIFY PnP mechanism. The software supports both IPv6 and IPv4, making it a versatile tool to have. Additionally, TekSIP can be deployed as a proxy for standard SIP phones to connect with a Microsoft Lync system. This is particularly useful as Lync supports IP phones that can support SRTP with SIP TLS transport. It registers standard SIP phones on behalf of them to the Lync system and maintains their presence status effectively. In conclusion, TekSIP is a must-have software for those in need of efficient, seamless and hassle-free SIP management.
Version 4.1.4: Route hunting [Requires SP license]. WebRTC improvements.