Downloading TekSIP 4.2 from our website was free. This program is an intellectual property of KaplanSoft. TekSIP lies within Internet & Network Tools, more precisely Network Tools. The most frequent installer filenames for the software include: TSManager.exe and _DDAD767F35C159795B133C.exe etc. The most popular versions of the tool 4.1, 3.7 and 3.6.
From the developer:
TekSIP is a SIP Registrar and SIP Proxy for Windows with support for UDP, TCP, TLS, and WebSocket transports. TekSIP complies with RFC 3261, RFC 3263, RFC 3311, RFC 3581 and RFC 3891. It also supports NAT traversal and ENUM. If installed behind UPnP supported Internet gateway device (ADSL router e.g.), TekSIP automatically detects if it is behind a new NAT gateway and the external IP address.
You may want to check out more software, such as FTP Navigator, CMUD or ICB2000, which might be related to TekSIP.