Sofia-SIP is a SIP user agent library, compliant with the IETF RFC3261 specification. It can be used as a building block for SIP client software for uses such as VoIP, IM, and many other real-time and person-to-person communication services. The primary target platform is GNU/Linux. Sofia-SIP is based on a SIP stack developed at the Nokia Research Center.
Ip phone Scanning Made Easy (ISME) scans a VOIP environment, adapts to enterprise VOIP, and exploits the possibilities of being connected directly to an IP Phone VLAN. It seeks to get the phone's configuration file directly from a TFTP server, enable SIP/SIPS (TCP/UDP), communicate with an embedded Web server and Web server banner, identify the editor by MAC address, and identify potential default login/password combinations which should be changed.
python-gammu is a set of Python bindings for Gammu, the GSM mobile manager for various cellular phones. It can work with any phone that Gammu supports, including many models by Nokia, Siemens, and Alcatel. python-gammu is now part of the Gammu project and it does not have separate releases anymore.
SipUnit provides a class library that allows software developers to create automated unit tests for SIP applications. Session Initiation Protocol (SIP) is widely used for providing telephone services over the Internet. SipUnit extends the JUnit framework to incorporate SIP-specific assertions, and it provides a high-level API for performing the SIP operations needed to interact with or invoke a test target. A test program using the SipUnit API is written in Java and acts as a network element that sends/receives SIP requests and responses.
Twinkle is a software phone for voice over IP communications using the SIP protocol. You can use it for direct IP phone to IP phone communication, or in a network using a SIP proxy to route your calls. Some of the features offered are call waiting, call hold, 3-way conference call, call transfer, and call reject. It supports STUN or a statically configured public IP address for NAT traversal. When using STUN, it will send keep-alive packets to keep NAT bindings alive. It supports ZRTP for secure voice communication.
oRTP is a library implementing the Real-time Transport Protocol (RFC3550), written in C. It is easy to use and provides a packet scheduler for sending and receiving packets on time, adaptive jitter compensation, automatic sending of RTCP compound packets, and the RTCP parser API. It works with IPv6.