Transition Networks
S4224 Web User Guide
33558 Rev. C
Page 232 of 669
Loss Measurement
Loss Measurement (LM) offers a way for operators to determine the amount of frame loss in an Ethernet
network (e.g., over an EVC). Specifically, LM is the ratio between undelivered OAM frames and the total
number of OAM frames transmitted during a specific time interval. ITU-T Y.1731 defines two types of LM:
1)
Single-Ended, where LM messages are transmitted to another MEP, which includes transmission and
reception frame counts in its response message. Here, only the LM initiator is able to derive frame loss
from the counters (since it does not include its local counters in the initial LM message); and
2
) Dual-Ended. Continuity Check messages are used to carry frame transmission and reception counters.
In contrast to the single-ended approach, this approach allows all MEPs inside a ME to derive frame loss,
instead of only the initiating node.
Enable
Loss Measurement based on transmitting/receiving CCM or LMM/LMR PDU can be enabled/disabled -
see 'Ended'. This is only valid with one Peer MEP configured.
Priority
The priority to be inserted as PCP bits in TAG (if any). In case of enable of Continuity Check and Loss
Measurement both implemented on SW based CCM, 'Priority' must be the same for both.
Frame rate
Select the frame rate of CCM/LMM PDU. This is the inverse of transmission period described in Y.1731.
300f/sec
selection is not valid.
100f/sec
selection is not valid.
10f/sec
selects ten frames-per-second as the frame rate of CCM/LMM PDU.
1f/sec
selects one frame-per-second as the frame rate of CCM/LMM PDU.
6f/min
selects six frames-per-minute as the frame rate of CCM/LMM PDU.
1f/min
selects one frame-per-minute as the frame rate of CCM/LMM PDU.
6f/hour
selects six frames-per-hour as the frame rate of CCM/LMM PDU.
If both Continuity Check and Loss Measurement are implemented and enabled on SW based CCM, the
'Frame Rate' must be the same for both.
Cast
Selection of CCM or LMM PDU transmitted
Uni
cast or
Multi
cast, where:
Uni
: The unicast MAC will be taken from the 'Unicast Peer MAC' configuration. If both Continuity Check
and dual ended Loss Measurement are implemented and enabled on SW based CCM, the 'Cast' setting
must be the same on both.
Multi
:
CCM or LMM PDU transmitted multicast.
Ended
Single
: Single-ended Loss Measurement implemented on LMM/LMR.
Dual
: Dual-ended Loss Measurement implemented on SW based CCM.
FLR Interval
The interval in seconds where the calculated Frame Loss Ratio (FLR) is displayed (0-65535 seconds).
