Problem with Polycom speakerphone into FXS port

I’ve just finished migrating 70 Nortel extension over to SIP/Asterisk/Aastra and all that is left are the Polycom (Soundpoint Premier) speaker phones in the 4 conference rooms. These are being connected to Sangoma FXS ports.

I’m having two issues. One is the FLASH button and the second is > 3-way calling.

The FLASH button on the speaker phone is not being recognized. I’ve messed with the ‘flash’ setting in zapata.conf but I think that only refers to Flash() dialplan application. I’ve also played with ‘debounce’ with no luck. Can anybody suggest something? Hanging up and picking up DOES work around the problem but I really want to have people continue to use the FLASH button.

Second, these Polycoms had the ability, on the old Nortel switch, to do n-way calling by repeatedly hitting the FLASH button and calling more parties. Is this possible with Asterisk? I know 3-way calling is possible and I know I can use Meetme for more parties, but I’d love to maintain the same functionality as before. Any ideas besides this one, which requires Asterisk trunk or 1.4?

Anybody know how to tweak the Flash settings for a ZAP extension? Asterisk doesn’t give me a second dial tone on my Polycom speaker phone (plugged into FXS port).