dialup.world is (currently) a three-line dial-up ISP!
Sounds for Asterisk, recorded by Pat Fleet (the original voice of Ma Bell).
A webapp for administering Asterisk from a web browser. Written in PHP. Worked on recently. Asterisk's API doesn't change very much so there probably doesn't need to be. Backed by MySQL. No obvious documentation so it'll need to be messed with to get installed.
A webapp which uses WebRTC and Javascript to test wether or not your STUN or TURN server is working.
Github: https://github.com/webrtc/samples/tree/gh-pages/src/content/peerconnection/trickle-ice
A curated list of telco resources and projects.
A new implementation of STUN and TURN. Full IPv6 support. Supports server authentication with the REST APi by the RFC. Implemented with Erlang.
V.23 Softmodem for Asterisk with some Bildschirmtext-specific stuff in it. Pretends to be a modem but it actually sets up a telnet-like TCP session to an IP address. Like many things with Asterisk, you have to compile everything from source with this module in a particular location.
A curated list of awesome Real Time Communications resources.
A small hobby software PBX for the tildeverse. So far users can make calls, leave voicemails and participate in a multi-user conference with more features to come. The numbers are loosely broken down by tilde, with each tilde having its own prefix "area code." It's set aside for tilde users only, and is not connected to the PSTN - you have to be an active tilde user just to get the admin's attention.
Baresip is a portable and modular SIP User-Agent with audio and video support. Tries to be a Swiss Army knife for SIP and VoIP. Supports encryption. Has an embedded web server with an HTTP (REST?) API for controlling the utility. Modular architecture.
A group of telephony hobbyists who restore and maintain old equipment. They figure out how to get their gear VoIP-enabled and built their own PSTN on top of the Net by hooking everything together. It's pretty serious, plus they document their work pretty well.
A security testing application that determines if Cisco VoIP hardware is in use, and if so drops the attacking box onto the VoIP VLAN by impersonating an IP telephone through a new virtual interface.
A lengthy how-to article about building an open source PBX using Linux and Asterisk that uses wireless for its network link. A fully portable wireless telephony system, in other words.
UCSniff is a VoIP & IP Video Security Assessment tool that integrates existing open source software into several useful features, allowing VoIP and IP Video owners and security professionals to rapidly test for the threat of unauthorized VoIP and Video Eavesdropping. Written in C/C++, and available on Linux and Windows, the software is free and available for anyone to download, under the GPLv3 license.
A software modem that pretends to be an analog dialup modem from the old days, only for communications it uses the IAX protocol to connect to an Asterisk VoIP switch rather than the PSTN.
An opensource voice chat system for use by gamers. Client/server architecture. Runs on Windows, Linux, an OSX.
A lightweight implementation of the server side of the Mumble protocol. Intended for use on embedded systems, but should compile just fine on full OSes. It specifically runs on Arch Linux and NetBSD, anyway...
HTML5 SIP client. Written in Javascript, throw it onto a page and configure it to contact a SIP gateway of some kind. Uses webRTC built into all modern web browsers. Does audio as well as video. Can contact the PSTN if the gateway can.
Github repo: https://github.com/DoubangoTelecom/sipml5
Javascript SIP client for VoIP. NodeJS backend. Uses WebRTC built into every modern browser. Found in the NPM collection, so it's easy to install (in theory).
FOSS speech recognition package. Supports over 100 languages and accents. Fairly lightweight in terms of dependencies. Can also output audio. Additional dictionaries can be added.