3 way calling is a feature from your telephone phone company it has nothing to do with what type of phone you have... it needs to be provisioned on your line from your local telephone carrier...
to initiate a 3 way call you dial the first call that you want to make as normal... when you are connected with that person, you can press the flash button (or switch hook on corded phones) to obtain dial tone... then you dial the second number... once the second person answers you can talk to them for a moment privately if wanted.. then press the flash button (or switch hook on corded phones) to join the calls together in a 3 way call..
to initiate a 3 way call you dial the first call that you want to make as normal... when you are connected with that person, you can press the flash button (or switch hook on corded phones) to obtain dial tone... then you dial the second number... once the second person answers you can talk to them for a moment privately if wanted.. then press the flash button (or switch hook on corded phones) to join the calls together in a 3 way call..