[MLB-WIRELESS] Free P2P phones will pressure telcos

Ryan Abbenhuys sneeze at alphalink.com.au
Wed Nov 12 22:25:53 EST 2003

Would yourself or a representative from your company be interested in
giving a presentation at a Melbourne Wireless meeting at some stage
perhaps?  Followed up with a TIB deal for those interested?

>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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