Brocade 6910 Ethernet Access Switch Configuration Guide (Supporting R2.2.0.0) - Manual (Page 1080)

1024 Brocade 6910 Ethernet Access Switch Configuration Guide
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Connectivity Fault Management
FIGURE 315 Transmitting One-Way Delay-Measure Messages
Transmitting On-Demand Loss-Measure Requests
Use the Administration > CFM (Transmit Single-Ended Loss Measure) page to send on-demand
single-ended loss-measure requests to a specified MEP within a maintenance association. These
messages can be used to measure near-end and far-end frame loss.
CLI References
• “ethernet cfm loss-measure single-ended” on page 567
Command Usage
• Both the source and destination MEP must be configured for the same MA before transmitting
loss-measure messages.
• A MEP cannot transmit periodic loss-measure and on-demand loss-measure messages at the
same time.
• Single-ended loss measurement (LM) is carried out by sending the specified number of loss
measurement request (LMM) PDUs to its peer MEP and receiveing loss measurement reply
(LMR) PDUs from its peer MEP to carry out loss measurements. The LMM PDU used for
carrying single-ended loss measure information is transmitting at an interval of 100 ms.
To perform loss measurement, a MEP periodically transmits LMM frames with the following
information element:
• TxFCf – Value of the local counter TxFC1 at the time of LMM frame transmission.
Whenever a valid LMM frame is received by a MEP, an LMR frame is generated and
transmitted to the requesting MEP. An LMR frame contains the following values:
• TxFCf – Value of TxFCf copied from the LMM frame.
• RxFCf – Value of local counter RxFC1 at the time of LMM frame reception.
• TxFCb – Value of local counter TxFC1 at the time of LMR frame transmission.