[Asterisk-Users] Oen source IP phone, maybe?

[mawali at news.icns.com]

Hi
The BOM that you have for a 8 bit uC based system comes to be high for 
the processing power you would need.
I would do it this way (I have already done it, but since I did it for 
someone else I cannot give it away).

Hardware
   1) A mips or arm based DSP/network processor
   2) Telephony interface (Slic/Slac, A/D etc) or Voice interface (Mic. 
            Seakers D/A ,etc) phone voice is 4KHZ so you dont need any 
            fancy stuff.
   3) Network interface (ethernet/usb or serial) you can build on that
   

Software
   1) uClinux (or mips-linux or arm-linux)
   2) DSP control/RTP abstraction
   3) Signalling stack (h323, mgcp are already available, maybe SIP)
   
A system like this would be able to drive 2 lines snd also do some fancy 
stuff.

Regards


On Tue, 19 Aug 2003, James Sharp wrote:

> On Tue, 19 Aug 2003, Michael Sandee wrote:
> 
> > I guess you will need some software/mem/cpu/flash too? getting it on a
> > cicuitboard etc?
> 
> Software would be opensource...get a couple of people together to write it
> RAM I missed, I thought the C400 had onboard ram, but it doesn't...so add 
> another $10.
> CPU is what the DS80C400 is.  Its a 8051-based microcontroller with a 
> built in ethernet controller and IPV4/V6 stack.  Its fairly easy to write 
> code for.
> There's also no need for much flash...you can DHCP/TFTP the C400.
> 
> 
> > 
> > You would be more looking at 200$+ for a full board... the thing is you
> > need something with drivers, or open standards hardware that you can
> > write drivers for. I've not seen much available boards with dsp etc...
> > one at broadcom iirc
> 
> Looking through the C400's documentation again, they indicate that its got 
> some Particularly Beefy(tm) math ability, which would eliminate the need 
> for an external DSP...just need an 8 bit DAC/ADC.
> 
> 
> > Case is probably not something you make just like that, you usually get
> > a design, and people make it... and thats very expensive... but it gets
> 
> For a phone, you are correct.  For an ATA-type thingie...a $10 black 
> plastic box from Radio Shack would do just fine.
> 
> 
> 
> > 
> > I've been dreaming about this aswell though ;) there are just many hooks
> > to it.. overcome audio problems, speakerphones, echo, echo cancelling...
> 
> You don't really need all of that for an ATA-type adapter, which is what I 
> was thinking of.  Of course a phone based on the same technology would be 
> much more.
> 
> Oof.  Forgot about DTMF decoding from the phone through the adapter.  
> Shouldn't be that hard...
> 
> Hmmm.  Price may be a bit higher than $40...but I'm positive it would be 
> less than an ATA-186 and you'd have full control over the code.
> 
> 
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