Hi Fabian,
Call pickup allows users to pick up incoming calls within their own call pickup group. The Cisco CallManager automatically dials the appropriate call pickup group number when a user activates this feature on a phone.
For this type of call pickup, you can configure audio and visual notification to the rest of the call pickup group members that a call is available for pickup. You can configure the following notification parameters in the Call Pickup Group Configuration window:
Type of notification (audio, visual, both, or neither)
Content of the visual notification message (called party identification, calling party identification, both, or neither)
Number of seconds delay between the time the call comes into the original called party and the notification to the rest of the call pickup group members.
***You can configure the type of audio notification that is provided when a phone is idle or in use in the Directory Number Configuration window.
Ring Setting (Phone Active)
From the drop-down list box, choose the ring setting that is used when this phone has another active call on a different line. Choose one of the following options:
Use system default
Disable**
Flash only**
Ring once
Ring
Beep only
From this good doc;
http://www.cisco.com/en/US/products/sw/voicesw/ps556/products_administration_guide_chapter09186a008055b5a0.html#wp1245287
Try one of the settings Disable** or Flash only**
Hope this helps!
Rob
