This attribute specifies how the address field extension bits are set in
the frame header. Consider the value to be a four bit binary number.
For example, 4 = 0100. Only the first headerLength bits are used.
For instance, suppose headerLength is 3, then the appropriate eaBits
is 2, or 0010. This attribute can be used to create a header of length
greater than two bytes or to specify incorrect eaBits in the header.