The UCL media tools include the Robust Audio Tool (RAT), the VIdeoConference tool (VIC), and the Network Text Editor (NTE). These tools provide for multi-party conferencing, over IPv6 or IPv4, with audio, video and text. These can be between two participants directly, using unicast, or between a number of participants on a common multicast group. All tools feature encryption so sessions can be kept private. The tools are available for a wide range of operating systems, and have been shipped as part of various packages including AccessGrid.
RAT is based on IETF standards, using Real-time Transport Protocol (RTP) above UDP/IP as its transport protocol, and conforming to the RTP profile for audio and videoconference with minimal control. RAT features a range of different rate and quality codecs (G.711, G.726, GSM, DVI, LPC), receiver based loss concealment to mask packet losses, and sender based channel coding in the form of redundant audio transmission.
VIC also uses RTP, and features a range of video codecs (H.261, H.263, H263+, JPEG, PVH, RAW/YUV, NV, Cellb), which allow for the choice of quality and bandwidth employed.
NTE provides for collaborative editing of text by multiple users, utilising a reliable multicast protocol to ensure integrity of the data across all users in a session. The tool features visual indication of text block editing and locking facilities for particular text blocks.