Usage: Dial(LCR/<interface>/<digits>/<options>)
The interface must match the interface name in interface.conf. If omitted,
the first remote interface is used.
Example:
Dial(LCR/ast/123) will send a call to LCR and select remote interface
'ast'.
Dial(LCR//123) will send a call to LCR and select the first remote
interface.
Now it is possible to have multiple remote interfaces.