FreePBX sitting on top of a CENTREX system, getting Link/Transfer to work?

I work for a large organization and am experimenting with Asterisk/FreePBX as it can provide us some very useful features and call metrics that we don’t otherwise have access to.

We are testing a basic proof-of-concept with a Linksys SPA3102 hooked up to one of our CENTREX-based telephone lines and a Nortel 2-line or equivalent phone.

We have everything working great, but we can’t transfer calls like we used to.

We used to be able to hit the Transfer/Link button and dial a number and the system would then blind transfer to the dialed number.

I assume there is a way to somehow replicate this functionality in FreePBX, but everything I have been able to dig up seems to refer to call waiting or other features. I’ve tried using the ## method but it just tells us all circuits are busy before re-dialing the CENTREX line.

Any ideas?

I think that some of the higher end gateways support flash transfer.

To support a large quantity of phones you can use a T1 card in the system and break out to Analog channels. Certainly as was pointed out the DAHDI drivers for the telephony cards support flash/hook/xfer events.

I think you may be able to get a switchook flash it to work using an FXO card but I doubt it will work well, if at all, with the SPA.

This post may help

You could add an inexpensive pay as you go sip provider (Vitelity, Flowroute, etc.) to your current setup (no hardware required) to give you additional outbound calling capacity. At 1.5c/min and no monthly recurring, it’s really a no brainer, even as a backup.

Finally, it’s been a while since I did anything with Centrex, but depending on how many extensions you have, I suspect you could save a bunch of $$$ dumping the Centrex as FPBX can do everything (and much more) it can.

Centrex typically transfers calls at the CO switch which then frees up the extension.

Asterisk/FPBX is the local switch (PBX) so unless the transfer is being made to another extension on the FPBX it needs both an incoming and outgoing path or trunk to the PSTN.

Assuming you only have 1 SPA3102 and are using the FXO port to connect to your Centrex line, you don’t have a second trunk available for the outbound leg of the transfer, hence the “all circuits are busy”

Are you able to transfer to another extension on the FPBX?

Thanks for the response!

Eventually that would be an option (when we are able to purchase more hardware), but for now does FPBX/Asterisk support a means to forward the transfer request somehow to the Centrex CO switch? It isn’t a big deal if we then lose the call on the FPBX line, I’m just wondering if this is somehow possible (maybe through a macro of some sort?).