The Alamin GSM SMS Gateway is a group of daemons that allows you to send/receive SMS messages from any GSM device that supports AT+ commands (GSM modems or GSM mobile phones) or supported by Gnokii. A client program allows you to send messages from any IP client. An SMTP interface is provided to allow MTAs to send SMS directly to the GSM network. IMP (Incoming Message Processor) modules allows you to extend functionality to implement banking, network administration, bd querys, etc. from a GSM mobile phone.
capircvd is a voice/fax gateway. It receives fax (G3) and voice-calls using an ISDN-Bus, an AVM ISDN-Card (active or passive) and CAPI20 from isdn4linux, or AVM. It can be used on either P2P (with DDI) or P2M S0-bus. After reception, it can process files (send as mail) using an external handler (included).
Bayonne is the telephony server of the GNU project. It offers a script-driven threaded multi-line state event telephony service on GNU/Linux, xBSD, and Microsoft Windows for building voice response systems, and uses telephony plugins for runtime driver configuration. It also features "TGI" for making Perl applications "telephony aware". It may be used to build telephony-based system administration, home automation, automated attendant, v-commerce, and voice messaging systems.
RAT is an RTP audio conferencing and streaming application that allows users to particpate in point-to-point and multi-point audio conferences over the Internet. Developing features include multiple sampling rates, mono/stereo, loss concealment, and IPv4/IPv6 support, and both versions feature encryption and run on a range of platforms.
mptc is a Perl script to help you work out whether you're on the cheapest mobile phone network/tariff for your phoning habits. You feed it an itemised phone bill and tariff pricing information, and it will tell you how much that bill would have cost on different tariffs. So far it only supports UK network pricing systems, but could easily be extended and applied in other countries.
The GNU Gatekeeper is a free H.323 gatekeeper based on the OpenH323 project. You can use it to manage a Voice-over-IP network and let endpoints (e.g., Netmeeting) communicate through symbolic names. It also has an external interface for billing and other applications. It runs on a number of Unix versions (including Linux and Solaris) and Windows.
Asterisk is a hybrid TDM and packet voice PBX (Private Branch eXchange) and IVR platform with ACD functionality. It acts as middleware between the Internet (IAX, SIP, MGCP, Skinny, H.323), telephony channels (like Zaptel, T1, PRI, E1, FXO, FXS, VoIP, VoFR, ISDN, modems, Internet Phone Jack, etc.), and applications (like voice-mail, conferencing, directories, MP3 players, intercoms, etc.). It has many advanced features such as a codec translation API. The base distribution includes several channel backends, as well as applications. However, the beauty of Asterisk is its ability to be extended using its APIs, dynamic module loader, and AGI scripting interface. End users can even write their own applications that run on the system in C or any scripting language of their choice.