Well there's no problem per se. I was curious what the cost structure was for.

It seems odd, frankly, to charge $.005 as if it actually costs Twilio anything close to that. I mean per minute, a phone call is eating up a very small amount of data in a pure IP environment, so the profit margins on a charge like that are obscene (personal opinion). 64kbps for one minute is about 4 megs, and I can guarantee that's not $.005 to Twilio (it's likely several orders of magnitude lower in fact, which makes that charge basically pure profit).

I just think it's wrong to charge for something that basically doesn't cost anything, and one that historically hasn't cost anything in Telcom (I'm referring to on-net calls here, at least over the last 20 or so years).

Perhaps you can clarify something else for me: if you bridge a call to a SIP endpoint, is it two calls, like transferring or one call plus a SIP charge? I haven't played with the API so I wasn't sure what mechanism they use to bridge the endpoint to the call.

Thanks so much for replying. Oh and one note, most carriers these days buy at sub $.01 per minute, so adding a 50% tax for SIP is not a peppercorn sum.

Disclaimer in the interest of full disclosure: I'm the marketing/community guy for 2600hz, the open-source cloud telecom company.

Edit: I reread this and realized it sounded a bit antagonistic. I'm really not trying to offend anyone, just trying to clarify why someone would be charging for on-net as that hasn't been the pattern in the industry for some time. It would be quite the coup if Twilio were able to bring back on-net billing as it is tremendously profitable. But again, I like the Twilio guys, I think they're amazing evangelists and they're doing great work in Telecom.

Telephone calls on Twilio consist of one or more legs, e.g. consider a call center application where a caller dials a Twilio local US number (first leg at 1¢/min), your application returns TwiML with instructions to bridge the call to a SIP address (a 2nd leg at 0.5¢/min), total cost 1.5¢/min.

I'm not sure if it's possible to initiate a SIP terminated call using the REST API, i.e. without PSTN/Client component. I haven't looked at the docs recently.

You may or may not be right in this being exorbitant. Who are we to judge? The market will decide! :)