Release notes: AMTMitelCRE 1.6.3.21

[Hilton Williams]

• 500 simultaneous calls tested. Handling more than 140-odd devices requires the stack size to be changed since Linux uses an 8MB stack for each thread ("ulimit -s 1024" to set the stack size to 1MB and "ulimit -n 8192" to set the number of open files to 8,192).
• Added support for external call control - the CRE recording can now be started or stopped by a external application. Enabled with OPTIONS->EXTERNALCALLCONTROL=1 in the INI file.
• A last call info request to AMTMitel is now made before the call is completed, in case AMTMitel has better information than it had at the start of the recording.
• The jitter buffer is now limited to 400 entries (approx 2 seconds of audio at 20ms), instead of being allowed to grow without bounds.
• The jitter buffer now has an overflow flag when adding entries - if it overflows, a critical warning is sent to the AEM, a marker with a "*" is added, and the error is written to the log. The AEM and log entry can only occur once per file. The file is processed.
• Fixed bug where last block of the RTP stream might not be written (introduced in 1.6.3.20).
• Fixed bug where CRE crashes or hangs on shutdown.
• Fixed bug where CRE hangs on startup - this is due to the CRE now shutting down cleanly on the previous run, the HTTP server just hangs.
• Fixed crash if the Mitel decryption libraries fail to load.
• Packet check threads are now terminated quicker, resulting in a quicker shutdown.
• Packet counters for packets received and written to disk are now written in debug mode.
  
  There seems to be a minor bug if the call stops before the last packet received is processed. The result is that the last packet is discarded. I had this consistently while testing (e.g. 8 million packets received, 300 not written to disk when testing 300 streams).