1890   Clarification of Table B.1 recommended multicast range assignments

Created: 25 Sep 2023

Status: Not Applicable

Part: Part 8-1 (2020; Edition 2.1)

Links:

Page: 178

Clause: Annex B

Paragraph: Table B.1

Issue

The text in Annex B describes mandatory and recommended values for the six octets in a 61850 multicast message. The first octet is mandatory; the second, third, and fourth are recommended (Ed 2.1; these octets are often used to classify the message, and in the 8-1:2011 edition, the first three octets are listed as assigned by the IEEE and the fourth octet is mandatory by message type). The last two octets use the range defined in Table B.1.

The range shown for the last two octets in B.1 (for GOOSE, GSSE, ands SV) is 00-00 to 01-FF. I believe that the maximum range address was based on the limitations of some hardware implementations that existed when the standard was first published. In practice, however, most hardware implementations now accept the range 00-00 to FF-FF.

I propose updating Annex B to indicate that the range up to FF-FF may be available.

Proposal

Editorial change only
Change the last two octets of the Ending address (hexadecimal) in Table B.1 from 01-FF to FF-FF.

Since this is a recommended range only, any existing devices with a max range of 01-FF will still be conformant.