Integrated Telephone

[tabibu]

This is my idea:
There are multiple fixed line telecommunication technologies. The oldest which is still widely used is Analogue lines, an evolution of this is Digital Line phones which are mostly fabricated through a PABX and can receive and make several call simultaneously. The Latest is the Voip technology which involes using internet connectivity to carry voice traffic. Each one of them has a physical phone receiver but can be fabricated on a similar PABX (I know Alcatel OmniPCX 4400). My idea is to fabricate this devices into one receiver with an analogue/digital port (RJ11) and a Ethernet port (RJ45)/interfaces. This receiver and transmitter should include Voip and Analogue + Digital Protocols. An addition of a routing technique should also be included, this routing ensures that the voice traffic is transmitted through the lowest priced technology. So basically it's a phone that checks availability of a medium and chooses which one to use. This is aimed at reducing the need of a Voip gateway and using different phone receivers and complex PABXsses. It's just a beginning and some of the protocols might require a lot of fabrication.

Can Any one assist me with material on this or any ideas on how to get it done?

 

[Super_voip]

1st, decide what scale you are replacing Home, Small office, Large office or 1000 line PABX. Something for a home rquires simplicity while PABX replacement requires a whole different approach.

 

[tabibu]

Basically two terminals that can communicate and illustrate the capability to support least cost routing and integrate all the three technologies on to I telephone. I don't want to fabricate a whole PABX, just intelligent terminals that can communicate through their various available paths using a protocol.

 

[Super_voip]

Maybe you should build something like a Linksys SPA3000 into a phone.

 

[tabibu]

Thanks for the post Super_Voip
Almost there:
The authentication and call routing intelligence programmed into the SPA-3000 will connect the caller via the Internet to the far end destination with security and ease. Using the SPA-3000 at the far end, calls can be answered immediately or further processed as a local call to any legacy land line or mobile phone allowed by the SPA-3000 dial plan.
If power and/or IP network connectivity is lost to the unit or the VoIP service is down, calls can be sent to a traditional carrier via the FXO interface.
This covers the basic form of routing, If the internet is unavailable the phone should test for the other two mediums with priority on digital then analogue medium.
All this should be on a single circuit keeping it as basic as possible.

Can I get schematics of the SPA-3000 or an explained circuit of it?

 

[Super_voip]

Maybe look up "embedded asterisk" Asterisk or Trixbox are linux voip PABXs.
The embedded versions vary in size, some very small. Most hardware is public also.

 

[Super_voip]

Whoops, already been done,Linksys CIT400 Dual-Mode Internet Telephony Kit with Integrated Skype

 

[tabibu]

Thanx, I guess the approach of already fabricated devices is informative but also limiting.
If I can get explained circuits and an integrable point on the three circuits. For voip I think STP (CAT 5) cable is ok. Transmission and signal reception is key.
Can you assist in any way.

 

[Super_voip]

look up Texas DSP VOIP in google and you'll find nearly every VOIP product using VOIP. The idea that by sticking the right parts together will result in a usable product doesnt deal with the user/administrator interface. A lot of software is needed to get these working, logic analysers to see where things go wrong, protocol sniffers to monitor traffic and maybe a VOIP server/router. The key to good transmission & reception is to do with the delays between packets, too long and blahhhhh. For an ultra simple setup VOIP router or provider is required, just use the IP of the other phone. This is usually turned off on most systems as a lot of phones are attached to DHCP based systems.

 

[Super_voip]

One fast solution would be to use a Grandstream Budgetone 200, there is a lot of room inside(3 small boards), and use a micro to intecept the keystokes. Use this info for the LCR and if needed pass the digits to either an analogue or back to the Grandstream. The keyboards for both phones are most likey to be a matrix config. The Grandstream people have ground off the identifying marks on the DSP chip, however a quick google search for Grandstream Budgetone 200 and DSP should reveal the identity as Grandstream released the info in a press release. **broken link removed**
**broken link removed**
**broken link removed**
https://focus.ti.com/pdfs/bcg/spry098.pdf

If you use the board on the last link then the interfacing to an analogue phone circuit should be easier.