Permission to use a specific gateway

[martins]

Hi!
It would be a very nice feature if a gateway can be configured with usage permissions.
For example I do not want a fax extension to use a cheap VOIP call. Instead of this a number dialed on an analog fax extension should be routed always over PSTN lines.
Of course I could configure route priorities but it would be more easy to do it with "permissions"

br

Martin