In theory this is not needed. This port does not need bison.
One of its dependent ports (openh323) needs bison and openh323
already has USE_BISON in its makefile.
However, without this bento complains that the port needs
bison and fails to build the package.
OpenH323 project's H323 stack. (the other one is called opengatekeeper)
Works with all the H323 VideoPhone clients including voxilla, ohphone and
NetMeeting