I just bought a pair of Grandstreams Budgetone 100's for $65 each from Pulver* for a cross-country test. Boy am I impressed. The test was between Fremont, CA and Northampton, MA. The most striking thing was how quiet the connection was. (Sort of like going from phonographs to well-recorded CD's.)
The IP connection I had to from here to Northhampton was pretty good with the raw ping times around 125ms and only a few outliers at twice that.
The talk delay wasn't much of an impediment to conversation once one got used to pausing a bit longer to allow the other side to get their "packets" in.
The one feature of the phone that isn't usable at all over such a long delay is the speaker phone. Well, not unless you want to drive the other party totally stark-raving bonkers. The room acoustics will bounce their conversation back to them with what appears to be roughly 2x the above delays. I assume the speakerphone is meant for the times one is put on hold and one only needs to know when the other party returned to the phone.
I find the "save a few cents per minute" come-on of the VOIP to the Public Switched Telephone Network (PSTN) companies uninteresting. I can pick up my POTS line if I want "telco quality" communication. What I find tantalizing about VOIP is that one can run it end-to-end and get a much higher quality connection. I'm already spoiled by the Grandstream's ulaw/8khz end to end.
Even though 8khz ulaw is bog standard telco encoding, it sounds much better than an analog phone call over a public telephone network. No doubt one of the reasons is that there are no long wire runs for low-level analog signals between the user's phone and the telephone exchange. In my case there are 15,000 ft of wire as measured by a telephone lineman. This is even though I'm much less than two miles from the exchange. A second reason the digital phone may sound better is that it requires no "hybrid" transformers to combine and later separate the microphone and earphone signal. An analog phone call would use 4 of these, one in each phone, and one at each of the exchanges points where the users wires attach.
I'm seriously thinking of sending a Budgetone 100 to all my relatives for the holidays. This is one of those things like the fax machine; it is only useful to you if other folks have one too. Once critical mass is reached I expect to see an avalanche effect. I just wonder how long it will take for the sharp part of the curve to hit.
Note: Just so there is no misunderstanding here, running high-quality VOIP over the Internet will require a good quality broadband connection. If you have less than 128k it probably won't work very well for you. You need at least a cable modem or DSL. You also need an ISP that sells you a connection that is capable of 128kbits/sec (not just "up to 128kbits/sec" eg. with a tailwind, in the dead of night with a full moon).
In order to get the best voice quality one should select the highest quality codec the phone offers. Good phones will offer G.722-wideband. Instead of normal "phone quality" with 8,000 samples per second and 8-bits per sample, this wideband codec starts out with 16,000 samples per second and 16-bits per sample. That data is then compressed down to 64,000 bits per second to save bandwidth. I would recommend the following selection order for the codecs: G722, G711u (aka PCMU), G711a (aka PCMA), all-the-rest.
Q: How does one dial the phone? Does one dial by IP or hostname?
A1: There are two ways to dial. One can dial by IP (and on some phones by hostname). If the target phone is expecting a username, one has to dial that also. Since the phone keypad only has 10 number buttons, one has to use two or three keypresses for each character in the hostname or ip address depending. That is a lot of button presses. I can't see how this will be a very popular form of dialing.
A2: The second way to dial is to involve a SIP gateway service that assigns a short "extension" number to each phone. One then dials a 3-digit to 6-digit extension to place the call. One organization that provides a free gateway that does this is Free World Dial or Sipbroker (see above). I'm using FWD and it works fine. One advantage to being a member of one of these groups is that you get to dial a large number of people with a few button presses. There are often peering arrangements between different gateways that allow folks to easily dial people homed on other SIP gateways.
Q: Can't I use a software-only phone program on my computer and save the cost of the Grandstream's?
A: The "soft-phones" I've talked to all had awful sound quality. In addition they tended to have severe drop-out problems. I wasn't impressed.
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wolfgang.rupprecht+web@gmail.com
(Wolfgang S. Rupprecht)
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