LevelOne GTL-2691 - Manual (Page 1349)

C HAPTER 44 | CFM Commands
Delay Measure Operations
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Size: 64 bytes
Timeout: 5 seconds
C OMMAND M ODE
Privileged Exec
C OMMAND U SAGE
◆ Delay measurement can be used to measure frame delay and frame
delay variation between MEPs.
◆ A local MEP must be configured for the same MA before you can use
this command.
◆ If a MEP is enabled to generate frames with delay measurement (DM)
information, it periodically sends DM frames to its peer MEP in the same
MA., and expects to receive DM frames back from it.
◆ Frame delay measurement can be made only for two-way
measurements, where the MEP transmits a frame with DM request
information with the TxTimeStampf (Timestamp at the time of sending
a frame with DM request information), and the receiving MEP responds
with a frame with DM reply information with TxTimeStampf copied from
the DM request information, RxTimeStampf (Timestamp at the time of
receiving a frame with DM request information), and TxTimeStampb
(Timestamp at the time of transmitting a frame with DM reply
information):
Frame Delay = (RxTimeStampb-TxTimeStampf)-(TxTimeStampb-
RxTimeStampf)
◆ The MEP can also make two-way frame delay variation measurements
based on its ability to calculate the difference between two subsequent
two-way frame delay measurements.
E XAMPLE
This example sends periodic delay-measure requests to a remote MEP.
Console#ethernet cfm delay-measure two-way dest-mep 1 md voip ma rd
Type ESC to abort.
Sending 5 Ethernet CFM delay measurement message, timeout is 5 sec.
Sequence Delay Time (ms.) Delay Variation (ms.)
-------- ---------------- ---------------------
1 < 10 0
2 < 10 0
3 < 10 0
4 40 40
5 < 10 40
Success rate is 100% (5/5), delay time min/avg/max=0/8/40 ms.
Average frame delay variation is 16 ms.
Console#