To make external calls: (9504/9508)
1.If already on a call, end the call by pressing Drop or put it on hold by either pressing Hold or pressing the button which the call is on.
2.Press an idle Line Appearance or Call Appearance button.
3.Dial the telephone number.
•If using a Call Appearance button, some systems may require you to dialing a specific prefix when making external calls. Your system administrator will inform you if a prefix is required.
•To dial a personal speed dial, press FEATURE or # and select the speed dial between 80 and 89.
•To dial a system speed dial, press FEATURE or # and select a speed dial between 600 to 699.
•To select a number from the directory press 
CONTACTS .
4.You will hear the call progress. You can continue the call handsfree or switch to using the handset or headset (press the HEADSET button).