Description: This object shall be used to select the user plane layer 2 protocol (if any) to be used above the AAL. The first octet of this object shall be encoded as follows. Bits 5-7 (i.e. the three most significant bits) shall be set to 0; any other values shall be ignored. Bits 0-4 (i.e. the five least significant bits) shall be encoded as shown in the entry for 'User information layer 2 protocol (octet 6)' in Table 4-10/Q.2931. However, if no user plane layer 2 protocol is present above the AAL, then the first (and only) octet shall be encoded as '0b00000000'. If the encoding of the first octet requires subsequent octets, then bit 7 (i.e., the most significant bit) of each of these octets shall be set to 0; however, if it is set to 1, it shall be ignored. Bits 0-6 shall be encoded according to table 4-10/Q.2931. If more than one subsequent octet is needed, then octets shall appear in the order shown in figure 4-16/Q.2931.