If you use IMPLICIT tagging, a context specific tag replaces the UNIVERSAL class
tag, and it does not appear in the enocding.
If you use EXPLICIT tagging, both tags appear in the encoding.
John L
Eduard Lascu wrote:
Hello everybody,
Does anybody know whether BER would require the encoding of the type
information for every data field of a sequence? I know that if it uses the
UNIVERSAL class, the tags can tell what is the type that is encoded in the
VALUE field. However, if the sequence has some optional fields, than the
encoding should use CONTEXT SPECIFIC tags and the tags have different
meaning now (they must uniquely identify the fields of the structure).
Therefore the type information of the encoded fields is lost.
Is this a correct interpretation of the BER standard?
Best regards and thanks for the help,
Eddie L.
Eddie Lascu
Senior Software Developer, Associate
IBI Group
230 Richmond St. W., 5th Floor
Toronto ON M5V 1V6
Tel. (416) 596-1930 x312
Fax. (416) 596-0644
www.ibigroup.com
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