You can place a call with the Cisco IP Phone 7800 in any of the following ways: 
  Lift handset and dial the extension or 8 for an outside number 
  Press New Call soft-key and dial the number 
  If using a headset, press HEADSET and dial the number, or New Call if the headset is already 
active. 
  To  use the speakerphone, press SPEAKER and dial  the number 
  Dial the number.  Press “<X|” to backspace and correct input if required.  Press the Call soft-key 
or lift the handset to initiate the dialing. 
 
 
     
 
 
 
 
Ending a Call 
 
You can end a call using the handset, speakerphone, or headset. 
  If using the handset, hang up the handset or press the EndCall soft-key. 
  If using the head set press the HEADSET button or press the EndCall soft-key.  
  If using the speakerphone, press SPEAKER or press the EndCall soft-key. 
 
     
 
 
 
Muting a Call 
 
While on a call, you can mute the handset, headset, or speakerphone, preventing the party you are 
speaking to from hearing what you or someone else in the room is saying. 
  To mute a call, press MUTE   
  To disengage the mute function, press MUTE again.