This attribute indicates the data frame format of this LEC. This may
come from the lanType attribute, LECS or LES. The data frame
format is not unspecified for an operational LEC.
This attribute represents the 'C2' LEC state parameter in the ATM
Forum LANE specification.
Token Ring data frame format is not supported. The LEC does not
become operational if the LECS or LES specify a LAN type of
Token Ring.