asterisk users - Dec 2010 - Cisco IP Phones and AVAYA IP Phones: Provisioning the profile

Hi All;

In cisco IP Phone, I can assign for a features for the buttons at the Phone (one
button to be for call pickup and one button to be for call forward and button to
be for bridge and one button to be for another extension).

How can I do the same thin in the Cisco IP Phones (or other IP Phones) while
they are registering in Asterisk?

Regards
Bilal