Routing
From Yate Documentation
Yate has multiple routing modules. You can set all routing in a module or use a combination of them. A routing module is a module that handles (sees) the call.route message.
If more than one module is used, then the priority that is set in each configuration file associated to the module will be used. This priority will establish the order in which the modules handle the routing request. A numerically lower priority means a higher actual priority of the route. A module can add/modify parameters without handling the message.
This is the list of the routing modules and a HowTo for each of them: