I have solved it by enabling issabel-beta repo AFTER installing the whole netinstall script. I can install all the asterisk 13 packets less asterisk13-voicemail. There are conflicts between asterisk13-voicemail-imapstorage and asterisk13-voicemail-odbcstorage.
Lo he resuelto habilitando el repo de issabel-beta DESPUÉS de instalar el script entero. Puedo instalar todos los paquetes de asterisk 13 menos asterisk13-voicemail. Hay conflictos entre asterisk13-voicemail-imapstorage y asterisk13-voicemail-odbcstorage.
Resolving Dependencies
--> Running transaction check
---> Package asterisk13-voicemail-odbcstorage.x86_64 0:13.18.2-0.el7.centos will be installed
--> Processing Conflict: asterisk13-voicemail-13.18.2-0.el7.centos.x86_64 conflicts asterisk13-voicemail-odbcstorage
--> Finished Dependency Resolution
Error: asterisk13-voicemail conflicts with asterisk13-voicemail-odbcstorage-13.18.2-0.el7.centos.x86_64