Format Of Eth-Slm Messages; Slm Pdu Format - Juniper ACX1000 Configuration Manual

ACX Series Universal Access Router Configuration Guide

Format of ETH-SLM Messages

SLM PDU Format

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Synthetic loss messages (SLMs) support single-ended Ethernet synthetic loss
measurement (ETH-SLM) requests. This topic contains the following sections that
describe the formats of the SLM protocol data units (PDUs), SLR PDUs, and the data
iterator type length value (TLV).
The SLM PDU format is used by a MEP to transmit SLM information. The following
components are contained in SLM PDUs:
Source MEP ID—Source MEP ID is a 2-octet field where the last 13 least significant bits
are used to identify the MEP transmitting the SLM frame. MEP ID is unique within the
MEG.
Test ID—Test ID is a 4-octet field set by the transmitting MEP and is used to identify a
test when multiple tests run simultaneously between MEPs (including both concurrent
on-demand and proactive tests).
TxFCf—TxFCf is a 4-octet field that carries the number of SLM frames transmitted by
the MEP toward its peer MEP.
The following are the fields in an SLM PDU:
MEG Level—Configured maintenance domain level in the range 0–7.
Version—0.
OpCode—Identifies an OAM PDU type. For SLM, it is 55.
Flags—Set to all zeros.
TLV Offset—16.
Source MEP ID—A 2-octet field used to identify the MEP transmitting the SLM frame.
In this 2-octet field, the last 13 least significant bits are used to identify the MEP
transmitting the SLM frame. MEP ID is unique within the MEG.
RESV—Reserved fields are set to all zeros.
Test ID—A 4-octet field set by the transmitting MEP and used to identify a test when
multiple tests run simultaneously between MEPs (including both concurrent on-demand
and proactive tests).
TxFCf—A 4-octet field that carries the number of SLM frames transmitted by the MEP
toward its peer MEP.
Optional TLV—A data TLV may be included in any SLM transmitted. For the purpose
of ETH-SLM, the value part of data TLV is unspecified.
End TLV—All zeros octet value.
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