Up: Structure of Data
The length component of the data element indicates the length
(number of octets) of the content component with one of three
- short form - the length is given in one octet,
representing a range of numbers from 0 to 127 since the
first bit must be 0. For example, a length field of
01010110 indicates that the content field has = 86 octets.
- long form - the length is given in 2 to 127 octets,
allowing numbers from 128 through 21016-1. In practice,
numbers are in the lower end of the range. A 1 or 0 in bit
8 of each octet has the same meaning as in the identifier
field. For example, 10011001 00011010 indicates that the
content field has 3226 octets.
- indefinite form - the content of a structured data element
(the only kind allowed with this form) has a specific end-
of-content data element, given by two consecutive octets of
all zeros. The length field contains one octet, 10000000,
which signals that the end-of-content octets are present.
Tue Feb 27 17:07:18 EST 1996