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monitor ethernet delay-measurement

 

Syntax

Release Information

Command introduced in Junos OS Release 9.5.

local-mep option introduced in Junos OS Release 15.1.

Description

Start an ITU-T Y.1731 Ethernet 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.

Note

If you attempt to monitor delays to a nonexistent MAC address, you must type Ctrl +c to explicitly quit the monitor ethernet delay-measurement command and return to the CLI command prompt.

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 runtime 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:

Frame delayThe difference, in microseconds, between the time a frame is sent and when it is received.
Frame delay variationThe difference, in microseconds, between consecutive frame delay values. Frame delay variation is sometimes called “frame jitter.”

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

maintenance-domain md-nameName of an existing CFM maintenance domain.
maintenance-association ma-nameName of an existing CFM maintenance association.
one-wayMeasurement type is 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.
two-wayMeasurement type is 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.
mep remote-mep-idNumeric 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 8191.
remote-mac-addressUnicast 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.
count frame-count(Optional) Number of frames to send to the specified peer MEP. The range of values is 1 through 65,535 frames. The default value is 10 frames.
local-mep mep-id(Required when multiple MEPs are configured) Identifier for the local maintenance association end point.
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.
priority 802.1p value(Optional) Priority of the delay measurement request frame supported by both one-way delay measurement and two-way delay measurement. The range of values is from 0 through 7. The default value is zero.
size(Optional) Size of the data TLV to be included in the request frame. The range of values is from 1 through 1400 bytes.
no-session-id-tlv(Optional) Prevent insertion of the session ID TLV in the request frame.
xml(Optional) Allow the output of the command to be displayed in XML format supported by both one-way delay measurement and two-way delay measurement. Note that the only way to get output in XML format is to use the xml argument. The display xml command does not work.

Additional Information

To display the frame counts collected at an MEP as the result of this command, see the following command descriptions in the CLI Explorer:

  • show oam ethernet connectivity-fault-management interfaces detail

  • show oam ethernet connectivity-fault-management mep-database

  • show oam ethernet connectivity-fault-management mep-statistics

To display the statistics collected at an MEP as the result of this command, see the following command descriptions in the CLI Explorer.

  • show oam ethernet connectivity-fault-management delay-statistics

  • show oam ethernet connectivity-fault-management mep-statistics

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 CLI Explorer.

For a complete description of Ethernet frame delay measurement, see the ITU-T Y.1731 Ethernet Service OAM topics in the Junos OS Network Interfaces Library for Routing Devices.

Required Privilege Level

trace and maintenance

List of Sample Output

monitor ethernet delay-measurement one-way

monitor ethernet delay-measurement two-way

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

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:

  • Table 1 lists the run-time output fields for the monitor ethernet delay-measurement one-way command.

  • Table 2 lists the run-time output fields for the monitor ethernet delay-measurement two-way command.

Output fields are listed in the approximate order in which they appear.

Table 1: monitor ethernet delay-measurement one-way Output Fields

Output Field Name

Output Field Description

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.

1DM Frames sent

PDU frames sent to the remote MEP in this ETH-DM session.

Packets transmitted

Total number of 1DM PDU frames sent to the remote MEP during 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.

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.

Table 2: monitor ethernet delay-measurement two-way Output Fields

Output Field Name

Output Field Description

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.

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 frame jitter.

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.

Sample Output

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

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

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