New to Asterisk here.
I've setup my phone as a gsm gateway using bluetooth adapter. I then direct calls from the mobile device to a queue that has one member. The member is a soft phone.
extensions.conf looks like:
[incoming-mobile]
exten => s,1,Answer()
same => n,Queue(support)
same => n,Hangup()
This works pretty well. I get the call to the sip soft phone. However, while the call is active, if I receive antother call to my phone device, that call deosn't even reach asterisk. I see the multiple call notification on my phone but it does not go through to asterisk. So my questions:
Is it even possible to queue concurrent calls via chan_mobile or does that kind of thing require more advanced hardware (e.g. gateways with multiple channels)
Even if I had some gsm gateway with 30 sim cards, what happens to the 31st call. How do people handle queuing the calls, once all channels are taken? Seems like it's certainly possible
Any pointers much appreciated
Some facts
1) chan_mobile not support any gsm gateway, it is clearly stated in project docs.
2) there are no gsm gates or channel drivers supporting second call on same gsm sim card.
3) There are no even PHONES which support that. On all phones you have pause/hold first caller to get second call.
Nobody need this feature, so no expect it will be developed in near future.
Related
I want to send all extensions and conference bridge participants of asterisk voice to a analog telephone cable which is connected to a voicelogger ( recorder system) . How can it be done ?. I think this is possible by connecting Analog phone cable to ATA device ( linsys pap2) and sending stream to that ATA extension . But the challange is voicelogger is not an automatic answer machain .
First i have say you that idea is really strange. Asterisk can record all calls and record storage will cost much less then any analog device storage.
If you still insist you need it send to analog, you need multiple line analog device(every call record will require different wire).
Also you need FXS dahdi card and/or sip fxs adapter to connect your recorder.
You can orginize recording by using ChanSpy and/Or Confbridge as "ghost" call to all your calls with other dialling your fxs recording bank.
Complexity of such dialplan will be above average and require significant efforts and asterisk knowledge. You can read this links to get idea.
http://www.voip-info.org/wiki/view/Asterisk+n-way+call+HOWTO
http://www.voip-info.org/wiki/view/Asterisk+cmd+ChanSpy
http://www.voip-info.org/wiki/view/Asterisk+auto-dial+out
Other options you can have is record by asterisk and play recorded files one-by-one to your analog recorder or just use usual computer to playback files to recorder.
I found an interesting documeent about realisation of eCall (Emergency Call) in EU: http://www.heero-pilot.eu/ressource/static/files/heero_wp3_d3-3_final-operational-results_v2.3_final.pdf
Germany somehow did it on Asterisk. Whatever, I don't understand how they process MSD (minimal set of data) using Asterisk. In the call session for the first step caller sends DTMF signals to send MSD packet. As I understood, Asterisk must redirect this call to In-band modem on COM port or to another machine with such modem. After PSAP successfully received MSD for the second step caller switches to voice channel that must be redirected to some sip-client of PSAP operator. How they do it? Is there a way to receive DTMF signals w/o modem by using internal capabilities of Asterisk? How the same call to redirect to another SIP on the same time?
I suspect that you are referring to emergency services, rendered by emergency dialers - eg. for senior citizens. These are fairly common where I live, and I've created in the past a solution to handle the calls from these, based on Asterisk. The solution involved a way to intercept the various DTMF signals that the device generates, then making Asterisk do stuff with it. Back then, I used Asterisk 1.6 and it is pain staking, because I had to do everything from within a MeetMe bridge, and interact with Manager alot. Today, doing the same with Asterisk 12/13 and ARI is a breeze. Just remember one thing, most of these dialers will utilize the A,B,C,D DTMF signals, which are somewhat unknown to most people - they exist and Asterisk is very much capable of handling those.
The only snag is - make sure you are connected via a PRI, as most SIP carriers aren't aware of these signals, and their SIP trunks won't support this type of signalling.
Asterisk can send dtmf(natively,via command SendDTMF in dialplan or D option in Dial command) or any other sound(custom c/c++ app needed)
No, you not need special modem.
However there are no realisation acordinly to that document, you need do that yourself or hire someone
I have a GSM ModeM connected to a serial port, and I use it so send SMS upon certain events.
Since it is not Plug-and-Play, I am confused as to how I'll detect its connection status. Win APIs like GetCommState will obviously not work.
I could periodically send packets of data and check whether the data is being consumed or not, but I'm wary about the risks of polling over performance and clogging up the buffers which might be in use.
So, is there any other method, or some interrupt based thing, which I could use to check whether is still connected, via a serial port, to my system?
I'd be grateful for any help on this.
Thanks.
From Windows 7 onwards, use Windows Mobile Broadband API to get information about a GSM modem.
Serial ports are very primitive communication devices, they date from the very early days of computing. It is what you plugged your ASR-33 teletype into to start banging in your Fortran program. The only reason they are still around is because they are simple, hardware vendors like them because they don't have to spend money developing and supporting a custom api to use their device.
Still, even back in the sixties did a computer have a need to find out if a teletype was attached. Which is done through the hardware handshake signals. The DSR signal, Data Set Ready, is turned on by the device when it is powered up. If you use the .NET SerialPort class then you can check that signal with the SerialPort.DsrHolding property. If you use the winapi then use GetCommModemStatus(), MS_DSR_ON flag.
That still only tells you that some device is attached. If you want to find out that it is the modem that you wrote your program for then you can interrogate it with AT commands, a protocol that's specific to modems. No vendor implements this exactly the same way but you can usually count on an identification from the modem with the ATI command. Check the programming manual for the modem for details.
Im writing application that communicate (via serial port) with electronic device which i designed myself.
When my PC application starts - it opens available COM ports one by one and it sends some string ("What are you?" for example).
My device is programmed, to reply to that "magic question" with own ID (for example: "I am evil device for supervising employees").
When my PC software receive that "magic reply" it starts working normally and its not searching other ports anymore.
Of course im not using stupid questions in data transmission, its just example.
Question is - can i send strings like on all (not busy) ports, to discover my device?
If I can - how that "question" string should look? Are there any normalized standards?
This is not first project like this on my desk, but now im developing solution for little industry and i need to pay more attention what my application is doing, because there may be other devices connected to COM ports and I do not know how they can react.
Im sorry, if i made some language mistakes, english is my third language.
Thanks in advance for replies.
After Alvin Wong confirmed my concerns I thought about it again and redesigned my device discovery functionality, because I don't want to abandon that idea.
I will send unique-complicated-ID every 1-5 seconds from device.
When my PC starts - it will try to open sequentially all available ports and will listen for that ID for few seconds.
If application receive that ID - it will be confirmation, that port number/name is correct and I my connection is established.
No, you wouldn't want to do that.
When you are using COM serial port, you have no idea what is plugged into the port. It could be nothing, your device, a modem, a mouse (though I believe nobody uses this anymore...) or whatever you can't even imagine.
Imagine if it is connected to another computer (probably a Linux/router), sending things may lead to execution of "that command", thus creating unexpected effects (though your program may not notice). Or if it is some badly-programmed device, it may trigger a bug in the firmware, thus failing the device and making it malfunction.
In short, in the worst case, you can cause a catastrophic event.
Serial (RS232 or UART I assume) communications don't have a designated transfer protocol (in contrast to USB which has one) to identify a device, so it isn't fail-safe. The user must make sure he selected the correct port. This is probably one of the reasons why hardware manufacturers choose USB, and one of the reasons why USB is so popular, even to computer idiots.
I would like to use a GSM modem to make a voice call to a phone number, play a recorded message, wait for a digit to be pressed and then disconnect the call. The system needs to know if the line was busy, if the user answered and which digit was pressed by user (if any). It should drop the line if nothing is pressed in 30 seconds. If user presses the digit before the question is completed then the voice should stop (user doesn't have to wait). Also, it would be nice if system could handle invalid digits (play "invalid digit" message, play original message and wait for input). Multiple calls in parallel would be nice, but I guess this is not possible?
I have found this article which explains low-level interface quite nicely. However, this question is more pragmatic - which libraries and which GSM modem would you recommend? OS is Linux, modem can be either RS232 or USB. I would prefer Python, but C(++) is ok too.
BTW: this is not telemarketing, it is a notification system. Not that it matters... ;)
EDIT: I learned this system is known by keyword "IVR" (added for future searchers).
A modem is generally used for data transmission but it sounds like you are actually transmitting voice, albeit prerecorded voice, and tones.
Although you can achieve this with the extra voice capability of a voice modem as you have identified, it might actually be easier to use a GSM to VoIP gateway, unless you actually need the modems data capability for some reason.
You could connect the VoIP to GSM gateway to a low cost or free open source PABX (such as Asterisk) and use this to build your particular application.
Some gateways even support multiple SIMS so you can target the SIM which gives the lowest call rate for the number you are calling - for example if you know that the number you want to call is on a particular operator, then that operator may offer free 'on network' calls between it's SIMs. This might be an advantage if you are expecting to make a large number of calls.
If you do a web search for 'VoIP GSM gateways' you will find some examples.
The following link provides an overview also:
http://www.voip-info.org/wiki/view/VOIP+GSM+Gateways
I am no expert in this field but it is something of a personal project that I have wanted to dive into.
Here is what I think will be the best way to do this.
1 Get yourself a VOIP GSM Gateway like this: VOIP+GSM+Gateways
2 Link into an existing PABX system or download a free one like asterisk
Then you will need to follow the instructions of the PABX development to create your dial plans and routing. I don't know if there are any already out there but I'm sure you will find many examples of the bits and pieces you need.