monitor ethernet delay-measurement

Syntax

Release Information

Command introduced in Junos OS Release 9.5.

Description

(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.

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 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:

Frame delay

The difference, in microseconds, between the time a frame is sent and when it is received.

Frame delay variation

The difference, in microseconds, between consecutive frame delay values. 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-name

Name of an existing CFM maintenance domain.

maintenance-association ma-name

Name of an existing CFM maintenance association.

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.

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.

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.

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.

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:

• 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 Junos Interfaces Command Reference.

• 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 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

trace and maintenance

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:

• 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.

Sample Output

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

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

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