[ASN.1] Question on BER

[Wiehe Ulrich]

Dear ASN.1 experts   In order to solve an interoperability problem resulting from different interpretations of ITU-T X.690, your help on the following question is very much appreciated:   A BER encoded message contains a data type for which the abstract syntax is defined as   DataType ::= BIT STRING {  bitOne  (0),  bitTwo  (1),  bitThree (2),  bitSeven (6),  bitEight (7),  bitNine (8),  bitFour (3),  bitFive (4),  bitSix  (5),  bitTen  (9),  bitEleven  (10),  bitTwelve (11),  bitThirteen  (12),  bitFourteen  (13),  bitFifteen  (14),  bitNineteen  (18),  bitTwenty  (19),  bitTwentyone  (20),  bitTwentytwo  (21),  bitTwentythree  (22),  bitTwentyfour  (23),  bitTwentyfive  (24),  bitTwentysix  (25),  bitTwentyseven  (26),  bitTwentyeight  (27),  bitTwentynine  (28)} (SIZE (15..32))   The entity sending the message encodes this data type as:   03 TAG 02 length 00 no unused bits 80 bitOne set to 1, bitTwo to bitSeven set to 0   The entity receiving the message does not accept it due to the SIZE constraint not being respected and performs the appropriate error handling.   Now designers of the sending entity argue that ITU-T X.690 § 8.6.2.4 and § 11.2.2 allow the encoder to encode the data type as shown above whereas designers of the receiving entity do not share this view and insist on the SIZE constraint being respected.   Dear Experts, please let me know which of the above interpretations of ITU-T X.690 is correct and whether or not X.690 is incompatible to X.209 in this respect.     Thank you in advance   Ulrich Wiehe   GKS AG                                          Gesellschaft für Kommunikations Software         Tel:+496621 169139 MMC2                                      Fax:+49 6621 169 122 Breitenstr. 57                            Mobil: +49 151 14016088 D-36251 Bad Hersfeld                    e-mail: [EMAIL PROTECTED]