ATRAK-Xrecorder (ATC Data Recording System)

The ATRAK-Xrecorder system (powered by X-Software) records and replays all the visual activity of a session in the X Window system of an Air Traffic Controllers (ATC) working position. The software monitors and records all the X Protocol traffic between the server and the various clients on an X display. During replay, recorded X protocol data is used to recreate the clients and their resources along with the drawing request that the clients made to the X server. ATRAK-Xrecorder also tracks and replays cursor movements.

ATRAK-Xrecorder uses the RECORD and TEST extensions that are a part of X11R6.1. ATRAK-Xrecorder uses a recording stub inside the X Server from which it receives all the requests and events associated with that X Server. ATRAK-Xrecorder formats this data and stores it. ATRAK-Xrecorder takes snapshots at predetermined intervals. A snapshot is a dump of the entire state of the X Server at that point in time. Snapshots are used as synchronisation points during replay. That is, replay can only begin from a snapshot. Snapshots are also what facilitate support for the fast forward and rewind features. Snapshots are taken using a customised process that ensures that the application does not freeze.

ATRAK-Xrecorder is a software product that is supported on several platforms across UNIX, AIX and Linux and is software is licensed per workstation (X server).

The main features of ATRAK-Xrecorder include:

• Replay at different speeds
• Pause/Resume capability during replay
• Start replay from several points in the session
• Arbitrary start/stop of recording (X clients can be started up before recording begins)
• Turn on/off cursor movements during playback
• Ability to record to disk or tape
• Graphical user interface (GUI) for replay modes
• Ability to generate files with recorded snapshots

ICC's solution consists of a number of key components namely: -

• ATRAK-Xrecorder software
• ATRAK-Xrecorder private network
• Archive server
• Replay of recorded data
• Centralised storage
• Off-line archiving of recorded data

The ATRAK-Xrecorder solution delivers a number of benefits including: -

• No requirement to recompile or rewrite X applications for recording.
• Very accurate recording - X Protocol is recorded in the order in which the X Server received it.
• Independent of screen size
• The overhead associated with this method of recording is directly proportional to the volume of drawing activity associated with the X Server.
• Less storage is required than video recording