Simultaneous ringing

I’ve been trying to set up my Asterisk install so that when in incoming caller selects a voice menu option, it rings two lines simultaneously;

One being a SIP phone connected, the other dialing out via an analogue GSM card to call a mobile.

I’ve tried doing something like exten = 1,1,Dial(SIP/6000&DAHDI/g2/075154xxxx,40,${DIALOPTIONS}i)

But when selecting that option, the SIp phone on 6000 rings for 1 ring, then it goes dead while presumably the gsm trunk dials/connects the specified number as after a few seconds, you hear that ringing.

I’ve also tried setting up a Queue where SIP/6000 and DAHDI/g2/075154xxxx are set as members, however it exhibits the same behaviour as my previous attempt.

I’m using AsteriskGUI, but found it cannot do everything I want so I’ve been doing much of this ‘by hand’.

I’m new to Asterisk (First used it last night), and slowly but surely learning how things are working, but cannot for the life of me figure this one out.

It would seem the issue is answer detection.

If it turn on answer on polarity switch, or call progress then it works almost as expected, however it does not detect the answer.

Is there any way around this?

Get your PSTN provider to provide line reversal answer supervision.

The analogue interface in question is not a PSTN line, but rather a GSM interface card (Atcom AX4G).

You’ll have to ask the supplier, but from a quick skim of the manual, you may end up having to recode chan_dahdi to trawl the dmesg log.

Incidentally, putting 4 resonant antennas for the same band in each others’ near fields is not good RF design!

Could you elaborate on this?

I’m also open to suggestions that don’t involve making ring detection work for this card (but obviously, that is preferred!)