asterisk users - Jul 2012 - OT - Integration with building intercom systems

Hi,

Now and then, I'm facing environments in which it could be helpful to
integrate building intercom systems with Asterisk.

Those intercom systems are made of :
- a main panel, showing company names and equiped with a speaker, a
microphone and an optional video cam
- a doorstrike
- several intercom phone with an optional monitor and with a button
triggering door's opening,
- maybe other hidden components I'm not aware of.

I've noticed that these intercom phone are connected to the main panel
through a 4 or 5-wires cable.

More precisely, for the video case I have in mind, it's a 4-wires
cable: 2 thick wires (for energy ?) and 2 thin wires (for voice, video
and command).

Is there a standardized protocol available to run  voice, video and
command on 2-wires and most probably used by  intercom systems ?

Would you say it's possible to install several intercom phones on the
same line, both ringing at the same time (but only one of them being
able to answer) ?
If positive, is it possible to connect one intercom line to asterisk
and let an asterisk user talk or watch visitor before opening the door
(through a DTMF sequence, for instance) ?

Regards

Le 05/07/2012 15:21, Olivier a ?crit :
> [...]
> Would you say it's possible to install several intercom phones on the
> same line, both ringing at the same time (but only one of them being
> able to answer) ?
> If positive, is it possible to connect one intercom line to asterisk
> and let an asterisk user talk or watch visitor before opening the door
> (through a DTMF sequence, for instance) ?
>
Sure you can. Any intercom can be connected using a IP gw connected to 
asterisk. You then install an IP camera and it's done :-) Opening the 
door is done by sending the code using asterisk sendDTMF command.

That's what we do when using existing intercom. For new installations we 
use Mobotix products (IP doorphone in SIP).

-- 
Daniel

Il 05/07/2012 15.21, Olivier ha scritto:
> Now and then, I'm facing environments in which it could be helpful to
> integrate building intercom systems with Asterisk.
> Is there a standardized protocol available to run  voice, video and
> command on 2-wires and most probably used by  intercom systems ?
I think this is country specific, I know a quite large number of "de 
facto" standards but almost no real standard except the German FTZ 123 D
12.
Most door phone analog system here (Italy) consists of 3/4+1 (bus + 
individual ring signal) wires  and some more recent using proprietary 
digital protocols on a 2 wires bus. Sure I seen something similar in France.

Interfacing any old individual analog door phone to asterisk isn't so 
difficult using a door phone to fxo/fxo adapter like used to do with a 
legacy pbx.

The matter becomes more difficult approaching a building install as 
there are no devices to handle properly that.
I think the snom PA-1 may be a good candidate to play with because of a 
versatile I/O that could be interfaced to a custom "door-phone bridge to 
IP".

2012/7/5, giovanni.v <iax at keybits.org>:
>
> The matter becomes more difficult approaching a building install as
> there are no devices to handle properly that.
> I think the snom PA-1 may be a good candidate to play with because of a
> versatile I/O that could be interfaced to a custom "door-phone bridge
to
> IP".
Handling both audio and video seems difficult.

I think you are supposed to have a IP based terminal in order to carry both
video and audio.
If budget is accept, it is possible to setup several iOS devices as dedicated
SIP terminals


On Jul 6, 2012, at 8:49 AM, Olivier wrote:
> 2012/7/5, giovanni.v <iax at keybits.org>:
>> 
>> The matter becomes more difficult approaching a building install as
>> there are no devices to handle properly that.
>> I think the snom PA-1 may be a good candidate to play with because of a
>> versatile I/O that could be interfaced to a custom "door-phone
bridge to
>> IP".
> 
> Handling both audio and video seems difficult.
> 
> --
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