With version 2.0.0 of vbox the recorded files have a new header, that
does not only include compression mode and connection information, but
also information about the caller.
The current headers hold this information:
time of recording the message,
compression mode,
CALLER ID,
name,
telephone number,
city
With this information it's possible for other programs to get the
information about a message. The detailed format is described in the
file libvbox.h as structure vaheader_t (this file is not included in
debian gnu/linux; if you want to develop isdn programs you should get
the source code).