I have these Viking Electronics PA speakers that behave like a trunk line. When they are “Picked up”, they signal a tone on both the analog line and the speaker, and then patch the two-way audio through. I have the device connected to my FXO gateway.
In the analog PBX world (Panasonic KX-T824), one would dial “8x”, hear the tone, and begin speaking. I’m not sure how to configure FreePBX to allow such behavior.
Because of their bizarre mounting location (they have no accessible power or network wiring), one set of twisted pair is it. Plus they are expensive, and I really don’t want to buy SIP replacements.
The astute among us may ask: “Dave, isn’t that a sneaky way of asking the too-often-asked question about how to dial 9 for an outside line?”. The answer is yes and no. Yes, I need to make a connection to that trunk, but there is no number to dial out.
So they are loop start, no dialtone, no answer supervision (other than the inband tone)?
You either need to rephrase this in terms of whether there is an FXO gateway box that supports this, or fork out for a DAHDI compatible FXO card.
I’m pretty sure that Asterisk can support the DAHDI version of this, but FreePBX will probably try to dial at least one digit, unless you use custom diaplan. I suppose it is possible that using prefix, but no prepend or match parts, in the outbound route, will cause FreePBX to dial without any digits.
You might also be able to configure it as a DAHDI extension, but overide dahdi.conf to use FXO signalling, so not try to apply “battery” to the line.
You mention an FXO gateway. If doing it that way, this is likely to be more a question about the gateway, than about Asterisk/FreePBX. Assume you can stop it looking for dialtone, the main question is whether it insists on dialling at least one digit, which will get played over the speaker, possibly on top of the tone, from the PA system.
Asterisk cannot send “nothing” on a trunk. However, most FXO devices have a “dial plan” or “digit map” that can modify the number sent on the analog line. With most of these, the number can be rewritten to nothing. For those that can’t, you can usually rewrite the number to something that does not affect the remote device or service.
For example, set up an Outbound Route for the trunk in question with prepend 0, prefix 81, match pattern (blank). Then, when you dial 81, it will send 0 to the FXO gateway. In the gateway dial plan, convert 0 to (nothing).
That is correct, and in fact, the device ignores DTMF
Asterisk cannot send “nothing” on a trunk.
In retrospect, my original post was deficient in that I didn’t specify that the device was loop-start, and it will ignore DTMF digits sent (and humans can ignore them too).
It does, so that is the direction I will proceed. Thank you both for your assistance in this; it is greatly appreciated.