Asterisk has a number of optional build dependencies.  If you intend to use
any analogue PSTN hardware such as a DigiumTDM400P or plan on implementing
a key system which uses the app_meetme conferencing plugin you will need to
install the dahdi-linux and dahdi-tools software and drivers before compiling
Asterisk.  If you will instead use digital telephony hardware (not IP phones)
such as T1/E1 lines or a PRI, you'll need to install libpri, again before
compiling Asterisk.

Be sure to see /usr/doc/asterisk-13.13.1/sample_confs/ after installation
for any additional configuration files you may need.

If you have plans of using Asterisk with a database backend you may want to
install the alembic package.  Since version 12.0 the database schemas that
Asterisk uses are being captured in the form of python script files that use
alembic to create/update database schemas.  The asterisk package places these
database scripts in the /usr/doc/asterisk-13.13.1/ast-db-manage directory.

This build script supports the following flags:

 * MOH : [default = no]

   Set this flag to 'yes' if you would like to include some royalty-free
   music on hold sound files with your installation.  Setting this option
   will cause the build to download some sound files from the internet.

 * SOUNDS_EXTRA : [default = no]

   Set this flag to 'yes' if you would like to include the extra sound package
   with your installation.  Setting this option will cause the build to
   download some sound files from the internet.

 * VM_ODBC : [default = no]

   Set this flag to 'yes' if you would like to store your voicemail messages
   in a database.  This plugin requires the unixODBC package.  This flag will
   override the VM_IMAP flag if both are set to 'yes'.  You will probably want
   to install the alembic package to configure your database with the latest
   database schemas for Asterisk.

 * VM_IMAP : [default = no]

   Set this flag to 'yes' if you would like to store your voicemail messages
   on an IMAP server.  This plugin requires the University of Washingtons
   IMAP server source.  This flag will be overridden by the VM_ODBC flag if
   both are set to 'yes'.

 * G711_NEW : [default = no]

   Set this flag to 'yes' if you would like to use the newer G711 codec code.
   This requires a more powerful machine than would be normally required.

 * MEETME : [default = no]

   Set this flag to 'yes' if you would like to build the app_meetme plugin.
   This plugin is required for key style systems and conferencing using meetme.
   This plugin requires the dahdi-linux package for timing purposes.

Optional dependencies: alembic, dahdi-complete, libpri, unixODBC, pjsip.