en efecto instale asterisk puro version 11.2 sobre centos 7 en conjunto de Vtiger 7 y no me funciona me da exactamente el mismo problema
vi varios tutoriales y no logro salir del sigueinte problema
Connected to Asterisk 11.12.1 currently running on vtiger (pid = 5034)
[Oct 26 14:55:05] ERROR[5726]: utils.c:1386 ast_careful_fwrite: fwrite() returned error: Broken pipe
[Oct 26 14:55:05] ERROR[5726]: utils.c:1386 ast_careful_fwrite: fwrite() returned error: Broken pipe
== Connect attempt from '149.248.X.X' unable to authenticate