Requested revision
| Standard: | IEEE 802.1Q-2018 | Clause: | 17.7.14 |
| Clause title: | Definitions for the IEEE8021-SRP-MIB module | ||
Rationale for revision
The ieee8021SrpStreamTable includes the object ieee8021SrpStreamDataFramePriority
with the DESCRIPTION:
"The Priority Code Point (PCP) value that the referenced Stream will be tagged with. This value is used to distinguish Class A and Class B traffic."
The assigned SYNTAX is IEEE8021PriorityCodePoint, what is defined as:
IEEE8021PriorityCodePoint ::= TEXTUAL-CONVENTION
STATUS current
DESCRIPTION
"Bridge ports may encode or decode the PCP value of the
frames that traverse the port. This textual convention
names the possible encoding and decoding schemes that
the port may use. The priority and drop_eligible
parameters are encoded in the Priority Code Point (PCP)
field of the VLAN tag using the Priority Code Point
Encoding Table for the Port, and they are decoded from
the PCP using the Priority Code Point Decoding Table."
REFERENCE "12.6.2.6"
SYNTAX INTEGER {
codePoint8p0d(1),
codePoint7p1d(2),
codePoint6p2d(3),
codePoint5p3d(4)
}
This assigned SYNTAX does not conform to the DESCRIPTION of ieee8021SrpStreamDataFramePriority
and is not suitable to distinguish Class A and Class B streams.Proposed text
ieee8021SrpStreamDataFramePriority should be of SYNTAX IEEE8021PriorityValue.
Impact on existing networks
(1) For devices which provide the StreamTable with correct IEEE8021PriorityCodePoint values it is not possible to distinguish Class A and Class B streams.
(2) devices may ignore the IEEE8021PriorityCodePoint definition and provide the PCP value for the ieee8021SrpStreamDataFramePriority object in the stream table; But if Class A or Class B priority is changed to a value > 4, most MIB Browsers will consider this as error, because the IEEE8021PriorityCodePoint definition allows a maximum value of 4.
Originator
| Name: | Josef Dorr | Email: | josef.dorr@siemens.com<mailto:josef.dorr@siemens.com> |
| Affiliation: | Siemens AG | ||
| Submitted: | 2019-01-21 | ||