Is there a way to go to specified extension directly after lifting a handset in my voip phone (without dialing any number)?
For example: Immediately after I lift a handset Asterisk is connecting me to a conference or some other phone.
Is this even possible?
In DAHDI land, it’s immediate=yes. In the SIP world, it’s going to be up to your phone, whether or not it can be configured to dial an extension when the handset is lifted.
Like Malcolm said - if it’s a VoIP device it depends on the device features. This is usually called a “hotline” feature.