290   VLAN ID

This tissue has following status: green

Created: 11 Feb 2006

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Page: 115

Clause: Annex C

Paragraph:

Category: Issue for edition 2 of this part

Issue: In IEC 61850-8-1, Annex C, it is mentioned, that the use of VLAN support is optional. If the mechanism is used, the VLAN ID (VID) shall be set by configuration; if the mechanism is not used, it shall be set to 0.

This specification is ok. However, it has to be noted, that a switch supporting VLANs will alter the tag with a VID=0 by replacing this with the configured default VID, which can not be 0. As a consequence, a device that is not supporting the VLAN mechanism, may expect to receive frames with a VID=0. If the device can not be configured to receive a specific VID, it has to ignore the value of the VID field.

Proposal: Add a note to that paragraph that gives this hint. I.e. the note could read as follow:

NOTE 3: As a switch supporting VLANs will alter tags with a VID=0 by setting the VID value to the configured default VID value for that port, an IED receiving tagged frames shall not expect this frame having a specific VID. That means, if an IED is not supporting to be configured to receive messages with a specific VID, it has to ignore the value of the VID field.

Consider to add a further note, that it is recommended to support VLAN configuration in IEDs for sending messages.

Discussion Created Status
?
Ballot until Editor
31 Mar 06 green
24 Feb 06 final proposal 24-03-2006
changed to final proposal 24 Feb 06 final proposal
agreed. 16 Feb 06 red
The VLan header may also be removed from the switch since VLan is only used for Switch to Switch communication. Therefore, the Stack shall not only ignore the value of the VID filed but also be prepared to receive non-VLan Taged messages. 13 Feb 06 red

 

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