i cant access the corpotare directory from the IP Phone. my ccm is ver 4.1

Its Displaying "Authorization Required" on the IP Phone screen.

I have one CCM server 4.1(3).When i am trying to take services or directories from ip phones which is registered on CCM, is asking authorization username and password. I tried username and password which is associated with the phones. but it is not takng. CCM is not integrated with any AD system. How can i remove this Authorization. Pls help me... Thanks........Kunle