[Samba] why samba-tool allows password reset against Windows DC ?

[Yosel Lazaro Vera Gonzalez]

hi everybody this is my situation 

Why can I change the user password using samba-tool against a windows DC but when I try to do the same 
operation using a ldap library, throws the exception "Unsupported operation" ? 
I think the problem is the authentication method, How samba -tool authenticates to the LDAP protocol? 
It's possible make this operation using another LDAP library? 

PD: I accomplished this operation against a DC samba but not against windows DC