[otrs] Radius Problem

Hi all I have just installed otrs-2.1.7 and I am trying to configure radius customer authentication. I have added the following to my Config.pm file: $Self->{'Customer::AuthModule'} = 'Kernel::System::Auth::Radius'; $Self->{'Customer::AuthModule::Radius::Host'} = '10.106.11.20'; $Self->{'Customer::AuthModule::Radius::Password'} = 'xxxxxxxx'; Is there anymore that I need to do? I now receive the following error when trying to access customer.pl Can't locate object method "new" via package "Kernel::System::Auth::Radius" at /opt/otrs//Kernel/System/CustomerAuth.pm line 81, <PRODUCT> line 20. TIA