Poor man's VoIP...

No doubt - the "killer application" used over our Mesh network is VoIP.
The ability to make high-quality voice (and video) calls over this low-cost infrastructure is mind blowing.
Couple that with multiple Asterisk PBXs which we run, to interface the PSTN and provide futuristic feature-rich telephony and you got people waiting in line to get connected.
At present, other then soft-phones, which requires a computer, a device disliked by many, the 2nd lowest-cost alternative for a stand-alone phone which we use are ATAs.

These ATAs must be also modified to support 12v PoE (they are mostly 5v) and by the end of the day it comes to a rather costly solution for Rural India.
(not to mention the two analog telephones - and people do like these "fancier" speaker phones with caller-ID, etc.).

My mentor regarding low-cost VoIP hardware is the Australian David Rowe.
During his last visit to Dharamsala, we talked much about his remarkable and fresh idea - to develop a low-cost embedded Asterisk...
Naturally, we can't wait to test the first prototypes here on the mounts..
Nevertheless... When it comes to any VoIP system, the major cost factor is the price of the telephones not the PBX not the PSTN interfaces, etc..
I was therefor thrilled, when David emailed me last week about his new $10 ATA idea.
Needless to say - this is something are welcoming with open arms.

Moreover, please consider this post as an open invitation to become involved - I doubt if David alone will be able to see through such a project, while we, here in Dharamsala can do little more then test and provide feedback.

Some general comments from my side - based mostly on gut feeling at this point:

1. People like feature-rich telephony and surprisingly are willing to pay for it.
So while a very limited RS232 phone should work - possibly it's not going to be adopted as widely as a fancy speaker-phone with a Caller-ID screen, speed-dials and message indicator.

2. Most routers we use DON'T have a USB port, while I'm yet to find one without an RS232 interface (two in most cases). So IMHO the natural interface is RS232 (3V3 one).

3. As David already mentioned - most of our router are on a mast top, 20-50 meters away form the desk. At times this is up to 90 meters. USB can be extended up to 25 meters by connecting 5 active cables in serial (active cables are like a passive cable with a hub at the end).
We buy (bulk) active USB2.0 cables for $19.99 !
So to get 25 meters - it's like buying two routers.

4. True, RS232 might not run that far at 115kbps... specially not at 3V3 levels...

5. The only conclusion - is to focus on a true FXS-ATA with ring generator and all... extend the analog local-loop as far as you need and allow connection of simple or fancy phones (incl. cordless, caller-id, etc).

6. Now comes the question - can we build that for less then $50 and can the router support 2 simultaneous calls ?
Even if the price is same, there is a huge advantage to integrating these two devices into one...

I suggest to post comments on David's blog...
It's a more relevant place for this discussion...

Volunteers ?

Thanks !

Yahel.
Dharamsala.