[SOLVED] Disabling Phones' Transfer capability

I have a small problem with the phones that I have, I have some Grandstreams, Yealinks and the new Digium D50’s.

What I need to do is stop the phones from being able to transfer, unless they use the Asterisk transfer feature of “*2” or “#1”. I need this so that the Asterisk server treats the call the correct way (I have a special way of logging transfers).

Users can currently press the “hard” or “soft” “transfer” button on respective phones, then doing an attended transfer (just seems to be attended, not blind ones) dials the extension normally and bypasses using my transfer_context. you can do exactly the same thing using the feature codes, but the feature codes use the transfer_context, which updates my databases correctly.

Is there an asterisk setting or way of only letting the phones transfer via the feature codes? The Grandstreams can just disable the “hard” buttons via a setting, which solves the problem for those phones, but I can’t see a way of doing this for the Yealinks or Digiums’.

Thank you for any and all help

Found the solution to this,

Just needed the line “allowtransfer=no” in SIP.conf general settings. Now you can only transfer via asterisk’s feature codes