Auto-dialing newly connected devices automatically


#1

So, I’ve thought of a potential fun way to use Asterisk in an Amateur Radio setting, however, I’m not sure if Asterisk can do what I would need it to do in order for it to work.

Let’s say I’ve got a repeater on the 70CM band that’s got a very strong transmit signal (the repeater can be heard by mobile and portable stations) everywhere, but some stations who are receiving the repeater strongly can’t hit it because of low transmit power.

I’d like to set up receive stations in these “holes” further out so that people working with handy-talkies and whatnot can hit the repeater via the remote receive stations.

I already know that Asterisk can do “voting” based on audio quality, etc, with certain modules; what I don’t know is if I can get Asterisk to auto-dial and connect a call to a SIP phone that has just connected.

I want to use a bunch of old, but still functioning, SIP phones to convert the audio from the remote receivers to SIP and send that audio stream to the repeater (running an AllStar node, which uses Asterisk), and I’d like to be able to program these phones to connect to either that AllStar node or another Asterisk server, and then have the server initiate a call to each device as soon as it connects.

Is it possible, currently, to have the server auto-initiate a call to a SIP device as soon as it registers on the Asterisk server? If so, how?

Thanks in advance.


#2

If the SIP phone has connected, it has presumably dialled Asterisk, so why would you want to dial it? It sounds like you want to configure the SIP devices for locked up calls, not do anything special an Asterisk.

I wasn’t aware that Asterisk had the level of audio processing necessary to detect a marginal FM connection.

I assume 70CM meant 70cm, as Coulomb-Morgans doesn’t make sense.


#3

In case of a power outage at a remote site, I want the phone to auto-connect to a conference-type-call running on the server. A Receiver radio will be doing the RF to AF conversion for us, and I want to feed the speaker out (the levels of which have been converted to line/mic levels) from the receiver into the mic side of the SIP phone…
I don’t know of a way to get a phone to auto-dial a conference type call at power-on… I also don’t know of a way for an Asterisk server to force that call to happen.
Thus the question: how do I get an Asterisk server to call to a device which has just registered on it?


#4

Autodialling a conference call is no different from autodialling any other call.

I imagine it can be done with Asterisk, but it will require writing an AMI script which monitors for registrations, and originates a call when it detects the device back on-line.


#5

I will look into that method. I’m wondering if there are other alternatives, as well… Something from within Asterisk which will allow me to do what needs done without the need for external scripts.

Thank you for your input, david551.


#6

Asterisk is a toolkit, so it generally provides the fundamentals to build things. Your request isn’t very common so as a result there is nothing built in or included to be the best of my knowledge.


#7

@jcolp Thanks for clearing that up. Such an option inbuilt to Asterisk would have been nice, and I understand it’s an odd thing. I’m no coder; the last time I wrote anything serious in any language was somewhere around 1994.
This is for a not-for-profit organisation (the Amateur Radio club to which I belong) and is being set up in the hopes of improving communications both for our hobby and for emergency communications (weather alerts and the like; public safety stuff).
ANY help the Asterisk team could provide for doing this would be appreciated not only by me, but by the entire Amateur Radio community at large.
Again, for this to work, what needs to happen is for the Asterisk server to initiate a call to a device upon its registration with the Asterisk server. A standard two-way SIP VoIP channel to the device is desired, so that audio from the receiver can get to the repeater to be re-transmitted, and so we can send DTMF tones to a decoder at the device to control functions on the radio (we’ll worry about the hardware to decode the tones and interface to the receivers, we just need the ability to send DTMF). Each device would need to be on its own “call”, so we can control each site individually. We’ll be relying on AllStar to do the voting at the repeater site so only the strongest signal wins and gets sent to the transmitter.