monitor ethernet delay-measurement

(Interfaces on Ethernet Dense Port Concentrators in MX Series routers only) Start an ITU-T Y.1731Ethernet frame delay measurement session between the specified local connectivity fault management (CFM) maintenance association end point (MEP) and the specified remote MEP, and display a summary of the frames exchanged in the measurement session. Frame delay measurement statistics are stored at one of the MEPs for later retrieval.

To start an Ethernet frame delay measurement session, the router initiates an exchange of frames carrying one-way or two-way frame delay measurement protocol data units (PDUs) between the local and remote MEPs. The frame counts—the types of and number of Ethernet frame delay measurement PDU frames exchanged to measure frame delay times—are displayed as the run-time output of the monitor ethernet delay-measurement command and are also stored at both the initiator and receiver MEPs for later retrieval. Ethernet frame delay measurement statistics, described below, are measured and stored at only one of the MEPs:

For one-way Ethernet frame delay measurement, only the receiver MEP (on the remote system) collects statistics. For two-way Ethernet frame delay measurement, only the initiator MEP (on the local system) collects statistics.

Options

two-way — Perform two-way Ethernet frame delay measurement, which is based on the difference between the time at which the initiator MEP sends a two-way delay measurement message (DMM) frame and the time at which the initiator MEP receives an associated two-way delay measurement reply (DMR) frame from the responder MEP, subtracting the time elapsed at the responder MEP.

maintenance-association ma-name — Name of an existing CFM maintenance association.

remote-mac-address — Unicast MAC address of the peer MEP with which to perform Ethernet frame delay measurement. Specify the MAC address as six hexadecimal bytes in one of the following formats: nnnn.nnnn.nnnn or nn:nn:nn:nn:nn:nn. For example, 0011.2233.4455 or 00:11:22:33:44:55. Multicast MAC addresses are not supported.

mep remote-mep-id — Numeric identifier of the peer MEP with which to perform Ethernet frame delay measurement. The discovered MAC address of the peer MEP is used. The range of values is 1 through 8192.

one-way — Perform one-way Ethernet frame delay measurement, which is based on the difference between the time at which the initiator MEP sends a one-way delay measurement request (1DM) frame and the time at which the receiver MEP receives the frame.

count frame-count — (Optional) Number of frames to send to the specified peer MEP. The range of values is 1 through 65535 frames. The default value is 10 frames.

wait interval-seconds — (Optional) Number of seconds to wait between sending frames. The range of values is from 1 through 255 seconds. The default value is 1 second.

Additional Information

To display the frame counts collected at an MEP as the result of this command, see the following command descriptions in the JUNOS Interfaces Command Reference:

To display the statistics collected at an MEP as the result of this command, see the following command descriptions in the JUNOS Interfaces Command Reference.

To clear both the frame counts and the statistics collected for MEPs, use the clear oam ethernet connectivity-fault-management statistics command, described in the JUNOS Interfaces Command Reference.

For a complete description of Ethernet frame delay measurement, see the ITU-T Y.1731 Ethernet Service OAM topics in the JUNOS Network Interfaces Configuration Guide.

Required Privilege Level

List of Sample Output

Output Fields

The monitor ethernet delay-measurement command displays different output at the CLI, depending on whether you start a one-way or two-way frame delay measurement:

Sample Output

Output Section	Output Field Name	Output Field Description
Session Description
When a one-way Ethernet frame delay measurement session begins, the following static information about the session displays at the CLI output:
	One-way ETH-DM request to	Unicast MAC address of the remote peer MEP.
	Interface	Name of the Ethernet physical, logical, or trunk interface to which the local MEP is attached
Session Status^†
Each time the router transmits a 1DM frame from the local MEP to the remote MEP in this measurement session, the following information updates in the CLI output as a runtime display of the session status:
	1DM Frames sent	Running count of 1DM PDU frames sent to the remote MEP in this ETH-DM session.
Session Summary
After a one-way Ethernet frame delay measurement session completes, session summary information—from the perspective of the initiator MEP—displays at the CLI output. The following information displays below the “– – – Delay measurement statistics – – –” heading:
	Packets transmitted	Total number of 1DM PDU frames sent to the remote MEP during this measurement session.
	Average delay	Note: For one-way delay measurement, these CLI output fields display NA (“not applicable” at the initiator MEP) because one-way frame delay measurements occur at the receiver MEP. For the same reason, one-way Ethernet frame delay measurement statistics can be retrieved later (using show oam ethernet connectivity-fault-management commands) at the receiver MEP only.
	Average delay variation
	Best case delay
	Worst case delay

^†You can view the one-way frame delay statistics for an Ethernet frame delay measurement session at any time by displaying statistics collected at the remote router for the CFM session (pair of peer MEPs). Use the show oam ethernet connectivity-fault-management command to display delay-statistics or mep-statistics at the remote router, for the remote (receiver) MEP. At either router, you can view Ethernet frame delay measurement frame counts—from the perspective of an MEP on that router—at any time. Use the show oam ethernet connectivity-fault-management mep-database command to display CFM database information for MEPs, or use the show oam ethernet connectivity-fault-management interfaces command in detail or extensive mode to display CFM database information for Ethernet interfaces attached to MEPs.

Output Section	Output Field Name	Output Field Description
Session Description
When a two-way Ethernet frame delay measurement session begins, the following static information about the session displays at the CLI output:
	Two-way Ethernet frame delay measurement request to	Unicast MAC address of the remote peer MEP.
	Interface	Name of the Ethernet physical, logical, or trunk interface to which the local MEP is attached
Session Status^†
Each time the router receives a DMR frame at the initiator MEP from the remote MEP in this measurement session, the following new frame delay statistics appear in the CLI output as a runtime display of the session status:
	DMR received from	Unicast MAC address of the remote MEP that transmitted this DMR frame in response to a DMM frame.
	Delay	Two-way delay, in microseconds, for the initiator-transmitted DMM frame.
	Delay variation	Difference, in microseconds, between the current and previous delay values. This is also known as “jitter”.
Session Summary
After a two-way Ethernet frame delay measurement session completes, session summary information—from the perspective of the initiator MEP—displays at the CLI output. The following information displays below the “– – – Delay measurement statistics – – –” heading:
	Packets transmitted	Total number of DMM PDU frames sent to the remote MEP in this measurement session.
	Valid packets received	Total number of DMR PDU frames received from the remote MEP in this measurement session.
	Average delay	Average two-way frame delay measured in this session.
	Average delay variation	Average frame jitter measured in this session.
	Best case delay	Lowest two-way frame delay measured in this session.
	Worst case delay	Highest two-way frame delay measured in this session.

^†You can view two-way frame delay statistics for an Ethernet frame delay measurement session at any time by displaying statistics collected at the local router for the CFM session (pair of peer MEPs). Use the show oam ethernet connectivity-fault-management command to display delay-statistics or mep-statistcis at the local router, for the local (initiator) MEP. At either router, you can view Ethernet delay measurement frame counts—from the perspective of an MEP on that router—at any time. Use the show oam ethernet connectivity-fault-management mep-database command to display CFM database information for MEPs, or use the show oam ethernet connectivity-fault-management interfaces command in detail or extensive mode to display CFM database information for Ethernet interfaces attached to MEPs.

monitor ethernet delay-measurement one-way

user@host> monitor ethernet delay-measurement
               one-way 00:05:85:73:39:4a maintenance-domain md6 maintenance-association
               ma6 count 10

One-way ETH-DM request to 00:05:85:73:39:4a, Interface xe-5/0/0.0
1DM Frames sent : 10
--- Delay measurement statistics ---
Packets transmitted: 10
Average delay: NA, Average delay variation: NA
Best case delay: NA, Worst case delay: NA

monitor ethernet delay-measurement two-way

user@host> monitor ethernet delay-measurement
               two-way 00:05:85:73:39:4a maintenance-domain md6 maintenance-association
               ma6 count 10

Two-way ETH-DM request to 00:05:85:73:39:4a, Interface xe-5/0/0.0
DMR received from 00:05:85:73:39:4a Delay: 100 usec Delay variation: 0 usec
DMR received from 00:05:85:73:39:4a Delay: 92 usec Delay variation: 8 usec
DMR received from 00:05:85:73:39:4a Delay: 92 usec Delay variation: 0 usec
DMR received from 00:05:85:73:39:4a Delay: 111 usec Delay variation: 19 usec
DMR received from 00:05:85:73:39:4a Delay: 110 usec Delay variation: 1 usec
DMR received from 00:05:85:73:39:4a Delay: 119 usec Delay variation: 9 usec
DMR received from 00:05:85:73:39:4a Delay: 122 usec Delay variation: 3 usec
DMR received from 00:05:85:73:39:4a Delay: 92 usec Delay variation: 30 usec
DMR received from 00:05:85:73:39:4a Delay: 92 usec Delay variation: 0 usec
DMR received from 00:05:85:73:39:4a Delay: 108 usec Delay variation: 16 usec

--- Delay measurement statistics ---
Packets transmitted: 10, Valid packets received: 10
Average delay: 103 usec, Average delay variation: 8 usec
Best case delay: 92 usec, Worst case delay: 122 usec

monitor ethernet delay-measurement two-way (Invalid DMR Frames Received)

user@host> monitor ethernet delay-measurement
               two-way 00:05:85:73:39:4a maintenance-domain md6 maintenance-association
               ma6 count 10

Two-way ETH-DM request to 00:05:85:73:39:4a, Interface xe-5/0/0.0
DMR received from 00:05:85:73:39:4a Delay: 100 usec Delay variation: 0 usec
DMR received from 00:05:85:73:39:4a Delay: 92 usec Delay variation: 8 usec
DMR received from 00:05:85:73:39:4a Delay: 92 usec Delay variation: 0 usec
DMR received from 00:05:85:73:39:4a Delay: 111 usec Delay variation: 19 usec
DMR received from 00:05:85:73:39:4a Delay: 110 usec Delay variation: 1 usec
DMR received from 00:05:85:73:39:4a Delay: 119 usec Delay variation: 9 usec
DMR received from 00:05:85:73:39:4a Delay: 122 usec Delay variation: 3 usec
DMR received from 00:05:85:73:39:4a Delay: 92 usec Delay variation: 30 usec
DMR received from 00:05:85:73:39:4a with invalid timestamp(s).
DMR received from 00:05:85:73:39:4a Delay: 108 usec Delay variation: 16 usec

--- Delay measurement statistics ---
Packets transmitted: 10, Valid packets received: 9, Invalid packets received: 1
Average delay: 105 usec, Average delay variation: 9 usec
Best case delay: 92 usec, Worst case delay: 122 usec

Syntax