[MLB-WIRELESS] Free P2P phones will pressure telcos

Damian Halloran damian at phit.com.au
Wed Nov 12 22:09:41 EST 2003

So that I'm not howled down by all and sundry this is a FYI post not a 
"shameless" plug.

I work for a company who distribute IP telephony units aimed at the 
home user.  These units work through the USB port of Windows (only - 
damn) computers and even though they come with their own software they 
work with Skype.

With the supplied software all units generate their own ring and dial 
tones, have an international prefix for telephone numbers,  and are 
registered with a central server in Taiwan.  We've tested them with 
broadband as well as dial-up and in both cases I would give the quality 
of the call an 8 (if PSTN is the benchmark of 10).  Making calls is 
simply a case of picking up the handset and dialling.

They come in three flavours: A PSTN/IP phone model that allows you to 
connect an analogue handset to it, as well as a PSTN line.  Nothing 
really fancy about this unit but you can attach a cordless analogue 
handset to it, and attach it to a PABX for incoming and outgoing IP 
telephone calls.

The next model is a handset type for your travelling person.

The third model has all the same features as the first, but it also 
allows call hop off so you can call from the IP network to PSTN and 
vice versa, and call forwarding features.  We've tested call forwarding 
to PSTN and mobile telephones and again the quality is about 8.

The only costs associated is the hardware, they don't charge for the 

The only downside is that it is a "closed" network, ie you can only 
ring another one of the units.

So that it doesn't come across as a plug I'll leave out the name of the 
equipment, and supplier.  If people do want more info you can e-mail me 


Damian Halloran.

On 12/11/2003, at 4:06 PM, Tony Langdon wrote:

>> Well, it would partly work, but you wouldn't be able to dial
>> (afaik) as the
>> soundcard input doesn't detect DTMF (afaik). You'd still need
>> to dial via
>> the software phone.
> Hmm, perhaps the IRLP style approach (but with phone handsets and 
> hardware
> based line simulators, instead of radios) is the way to setup a VoIP IP
> ohone network.  The idea is actually quite simple in concept.
> 1.  Define a numbering scheme.  This can be a simple "flat" scheme 
> like ICQ
> (basically the ham VoIP apps work this way), or something more complex 
> using
> international prefixes and the like.  I prefer KISS, we're not billing 
> here.
> :-)
> 2.  Setup some form of address resolution.  This could use DNS
> (12345.freeipphone.org, etc), or some specialised server based scheme 
> (the
> ham systems have their own schemes for address resolution).
> 3.  Define some sort of hardware interface to connect the phone to the 
> PC.
> The interface would need to generate ring voltage (80V AC - oscillator,
> audio power amp and a transformer should do), and all the necessary 
> voltages
> and signalling to make an ordinary POTS handset work.  The interface 
> could
> also include a DTMF decoder chip so it can perform this function as 
> well.
> Alternatively, you could write this function into the software (I have 
> seen
> both approaches used, but the hardware one works best).  Hardware 
> decoding
> also makes it easy to script in special functionity that can be 
> accessed
> whenever the phone is off hook, regardless of whether it's on a call 
> or not
> (a la IRLP).
> 3.  Start with some existing piece of open source software.  Hack it 
> to work
> with the above interface for call establishment and termination, so 
> all the
> user has to do is treat it like a normal phone - just pick it up and 
> dial
> (or answer).  For our application, probably one of the SIP based VoIP
> packages would be most appropriate.
> 4.  Build on extra functionality outside the package.  Shell scripting 
> can
> work well here, and make the package very "hackable".  That's one of 
> the
> strengths of IRLP in the radio world.  If the functionality is not 
> there,
> chances are you can add it in. :)
> Of course, the hardest part will be getting the hardware out there.  
> Now, if
> any of us is involved in electronic manufacturing, that would help.  
> Good
> thing is it won't need Austel/ACA approval, as it's not interfacing to 
> the
> phone line, just your PC. :-)
> Might also be a good project for mags like Silicon Chip. :)
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Damian Halloran B Comp
P: 03 8430 8691
M: 0419 308 036
F: 03 9417 1848
E: damian at phit.com.au

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