17 March 2005

Brave New VoIP World

We’ve made the plunge into the VoIP (Voice over IP: transmitting telephone calls over the Internet) world. After a few months of paying $20 a month on long distance I figured there must be better way. Our local phone company’s best plan without a monthly fee is 18¢ per minute. AT&T has a no monthly fee plan for 10¢ per minute, except that you pay a much higher rate for in-state long distance. MCI doesn’t even offer a no monthly fee plan any more.

Enter Internet long distance. A variety of VoIP companies offer long distance to the anywhere in the US, Canada, and most of western Europe for 2¢ per minute or less. No monthly fee. The only catch is that you have to get your call onto the internet. There are services that bundle a whole telephone line over the internet with long distance, a new phone number, and an interface box. These services also generally cost at least $20 per month. Worse yet, being a DSL customer out in the sticks, we can’t get DSL without a plain old telephone line. No use paying for two phone lines.

But you aren’t stuck with a package deal, you can always get your own interface box and buy your own long distance and still use the existing phone line you already have. In our case we got a Sipura SPA-3000 from AsteriskMall and setup Asterisk on a spare computer. With some amount of configuration work, we’ve got outgoing local calls still traversing the POTS line, outgoing long distance going over the Internet to our VoIP long distance provider (saving us 8-16¢ per minute), and incoming calls coming in over the POTS line. There are also some special numbers we can use to make free VoIP calls to other folks on the Internet like IAXtel’s 1-700 numbers and Free World Dialup. Free World Dialup in particular has free calling to anyone with the most popular bundle providers (Packet8, Vonage, etc.).

In the long run, our investment in the interface box will pay for itself in long distance savings in half a year. And since we still have our normal phone line which the interface box will fall back to automatically when there is a power outage we still get the E911 service, even when the power and/or Internet connection are not working.

This isn’t to say that this hasn’t been a bit of an adventure. The SPA-3000 has over one hundred configurable parameters and getting it configured correctly involved a lot of trial and error. (By the way, thanks to our parents who have been very kind about our phone calls as we try and get things working. “Can you hear me now?”) Voice quality has been fairly good though. The delay hasn’t been quite as bad as I had expected. It’s slightly better delay-wise than satellite calls across the Atlantic, but this depends on how Internet traffic is between our home and

  • Calls going out the POTS line are too quiet for both parties

    • Solved by increasing the PSTN Line “SPA to PSTN Gain” and “PSTN to SPA Gain” settings to 5 (dB presumably)

  • Calls going out the VoIP long distance have an echo for the people we call

    • Possibly solved by setting SIP “RTP Packet Size” to 0.010 (seconds)

  • Calls either way on the POTS line can’t make DTMF tones (touchtones) in call

    • No resolution yet

  • Calls either way on the POTS line rarely have an echo back to our phone when both sides are talking

    • No resolution yet

There is still a long ways we can go with this too. Now that we have Caller ID incoming calls can get special treatment depending on who they are and we can get some more powerful voice mail service as well.

Your call is important to us. Press 1 to learn about why paying for long distance service from the old communication monopolies is going to be obsolete in a dozen years…

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