1135   Example BER encoding of integer

Created: 21 Jun 2013

Status: In Force (green)

Part: Part 8-1 (2011; Edition 2)

Links:

Page: 141, 142

Clause: Table A.3

Paragraph:

Category: No impact on this part

Issue

Table A.3, which lists examples for BER encodings of integer values, uses encoding 0xFF 0x80 for value -128 and encoding 0xFF 0x80 0x00 for value -32768. In these encodings, all bits of the first byte and the MSB bit of the following byte are set. This is forbidden in BER encoding, as defined in ITU-T R. X.690: 2008, section 8.3.2.

Proposal

Use encoding 0x80 for value -128 and encoding 0x80 0x00 for value -32768.

Discussion Created Status
I understand that Table A.3 is for explaining fixed length encoding. However, some values in the BER column (not fixed length) are wrong and these should be corrected in ed.2.1.
These values are wrong:
BER value of INT16 -128 should be 0x80
BER value of INT32 -128 should be 0x80
BER value of INT64 -128 should be 0x80
BER value of INT32 -32768 should be 0x80 00
BER value of INT64 -32768 should be 0x80 00
24 Jan 17 In Force (green)
FIXED GOOSE encoding illustrated in Table A.3 is NOT BER, although - beneath fixed value length - shall be compatibleto BER. No change needed. 03 Feb 14 In Force (green)
accepted
However, the table A.3 illustrates the way of encoding the values in context of a FIXED GOOSE.
The BER value of INT16=-128 is 0x80, Fixed Size is 0xFF FF 80
The BER value of INT32=-32768 is 0x80 00, Fixed Size is 0xFF FF FF 80 00
19 Dec 13 Discussion (red)

 

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