Comment 6 for bug 141359

Yes, its separate feature, and won't help you much for your specific situation.
I for myself have an Asterisk running, so I'm connected to it via Coccinella using the IAX Phone feature. Since my asterisk is connected to an upstream SIP provider, that allows me to make/receive free calls to other parties using SIP or even cheap calls into the "ordinary" land lines or cell phones. Don't know whether there are IAX providers available on the Net like SIP providers are, and setting up Asterisk to translate the IAX to SIP is also not a 5 minute job ;) So this may or may not a feature for you ;)