How to define a key to refuse incoming call

Hi all, this is not a specifically FreePBX question, but maybe it is…
I would like to have the ability to define a “refuse” key, similar to the one provided on example by the snom 3xx series.
On certain kind of phones (i.e. atcom at320) you have to answer the call and then immediatly hangup; on another series of phones (DECT Siemens C450ip) the dedicated key (red phone) does not work and still you have to answer and then hangup.

Isn’t there any possibility to add a feature somewhere (features.conf ?) to design a key or key sequence to send a “SIP/2.0 486 Busy Here” message or something similar ?

thanks in advance,

you have to answer a channel to implement any sort of feature code in asterisk (unless you want to jump through several hoops to design something farily custom). What you want is typically fairly phone specific. For example, on the polycom, there is a ‘reject’ button that will send a ‘Busy Here’ back if you press it (same as if DND was on).

Thank you.
So if the designated key sending refuse SIP header without answering is not present or not functional, you cannot do anything to implement it. (Apart from wait for a better phone firmware).

I think your argoument is perfect, unfortunately…

thanks again,