The first call between two phones on Pidgin Talk, with audio in both directions.
Two phones, one call, sound both ways. Small thing, big grin.
How a call is put together
There are two ways to build a phone system. One passes a call from the caller straight through to whoever is being called, like a switchboard plugging in a cable. The other answers the caller itself, places a second call to the other party, and joins the two in the middle.
Pidgin Talk does the second. Every call is two separate legs with the system between them.
Why the harder way
It is more work, and it is what makes almost everything else possible:
- Hold: stop passing voice and play music to one leg.
- Transfer: keep one leg, swap the other.
- Voicemail and menus: the system is already in the call, so it can speak and listen.
- Recording: the audio already passes through.
Build it the easy way and each of those becomes a trick. Build it this way and they are ordinary operations on a leg. We would rather build the foundation once.
What happens when you dial
When extension 101 dials 102, the system checks that 101 is who it says it is, then rings every device signed in as 102 at once. The first to answer gets the call and the rest stop ringing.
An echo test
We also added a number that simply plays your own voice back to you: *43. It sounds silly and it is the most useful test there is. If you can hear yourself, the phone, the network and the system all work, and the problem is somewhere else.