Brocade 6910 Ethernet Access Switch Configuration Guide (Supporting R2.2.0.0) - Manual (Page 617)

Brocade 6910 Ethernet Access Switch Configuration Guide 561
53-1002651-02
25
CFM Commands
Command Usage
• Delay measurement can be used to measure frame delay and frame delay variation between
MEPs.
• Both the source and destination MEP must be configured for the same MA before using this
command.
• If a MEP is enabled to generate frames with delay measurement (DM) information, it sends the
specified number of DM frames to its peer MEP in the same MA, and expects to receive DM
frames back from it.
• When two-way frame delay measurement are made, the transmitting MEP sends 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.
Example
This example sends two-way 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#
show ethernet cfm delay-measure two-way
This command displays frame delay and frame delay variation of on-demand two-way
delay-measure tests.
Syntax
show ethernet cfm delay-measure two-way
Command Mode
Privileged Exec
Example
Console#show ethernet cfm delay-measure two-way
Transmit DMM Time Delay Time (ms.) Delay Variation (ms.)
-------------------- ---------------- ---------------------
Jun 18 05:04:37 2012 20 0
Jun 18 05:04:38 2012 20 0