This attribute specifies the DE to CLP mapping that is performed in
the Frame Relay to ATM direction.
When preserve is selected, the DE field in the Q.922 core frame is
mapped to the ATM CLP field of every cell generated by the
segmentation process of the AAL5 PDU containing the information
of that frame.
When always0 is selected, the CLP field of every ATM cell
generated by the segmentation process of the AAL5 PDU
containing the information of that frame is always set to 0.
When always1 is selected, the CLP field of every ATM cell
generated by the segmentation process of the AAL5 PDU
containing the information of that frame is always set to 1.