Robust Audio Tool (RAT)
The Robust Audio Tool (RAT) is a an open-source audio conferencing
and streaming application that allows users to particpate in audio
conferences over the internet. These can be between two participants
directly, or between a group of participants on a common multicast
RAT require no special features for point-to-point communication,
just a network connection and a soundcard. For multiparty
conferencing RAT uses IP multicast and therefore all participants must
reside on a multicast capable network. RAT is based on IETF
RTP above UDP/IP as its transport protocol, and
conforming to the
RTP profile for audio and video conference with minimal control.
RAT features a range of different rate and quality codecs, receiver
based loss concealment to mask packet losses, and sender based channel
coding in the form of redundant audio transmission. It offers better
sound quality relative to the network conditions than most audio tools
available. It also features encryption so you can keep your
RAT runs on a range of platforms: FreeBSD, HP-UX, IRIX, Linux,
NetBSD, Solaris, SunOS, and Windows 95/NT.
The source code is publicly available for porting to
other platforms and for modification by others. Later releases (4.x)
have an open source license. Source code can be obtained from the download page and by anonymous CVS.
RAT is just an audio application, it does not perform
call services like user location, neither does it listen to session
announcements to discover advertised multicast sessions. For these
purposes, it is recommended you use RAT in conjunction with the
Session Directory (SDR), or a similar application.