Calls now go out through the provider, steered by dialing rules kept as data.
Pidgin Talk can now call a real phone number. The first call went to a mobile on the desk next to the server, which rang, and was answered with more ceremony than it deserved.
Dialing rules are data
Which provider a call uses, and how the number is rewritten on the way, is decided by an ordered list of dialing rules. Each rule says:
- what the dialed number starts with,
- how many digits it may have,
- how many digits to strip from the front,
- what to put in front instead,
- and which provider to send it through.
The first rule that matches wins. The rules live in the database, not in code, so changing how an office dials never needs a new build or a restart.
Failing honestly
If a rule matches and its provider is down, the call fails and says why. It does not wander down the list looking for another route.
That is deliberate. A call that quietly goes out through a different provider may show the wrong caller ID or cost something nobody agreed to. A clear "no route" is better than a surprise on the bill.
Caller ID
The number shown to the person you are calling comes from the provider's settings. Providers only accept numbers that belong to your account, so getting this right is the difference between a call that connects and one that is refused.
Next
Calls go out. Calls coming in is the half that keeps an office in business.