06 Routing and dial plans
Pro tips
• Normalization is first match. A later rule does not repair a number an earlier rule already rewrote.
• A voice routing policy is an ordered list of PSTN usages. The first usage that contains a matching route wins.
• Direct Routing needs the user in TeamsOnly. Islands mode does not send that user's PSTN calls through Teams.
Interview traps
• Debugging the gateway when the dialed string never became E.164.
• Creating a route and forgetting to put its PSTN usage on the user's policy, in the right order.
Cheat sheet
Dialed string
-> tenant dial plan, first matching rule
-> E.164
-> voice routing policy usages, in order
-> first voice route regex that matches
-> online PSTN gateway list
Islands mode does not place Direct Routing calls.
Facts in the long lessons were checked 14 October 2026. This sheet is a memory aid.