OAM monitoring and reporting

General configuration parameters influence reporting probe frequency, the delay metric type to monitor, and retention of the delay measurement last reported.

The notification process uses the reporting command and threshold configurations. By default, reporting is enabled and the routing engine is informed of threshold events. At least one threshold must be configured to report to the routing engine. Disabling reporting allows the function to execute but prevents the reporting of threshold events to the routing engine. If this value is toggled and previously recorded, the reported value is cleared and the process returns to the initial reporting phase.

The probe frequency, configured using the interval command, defines the transmission rate of the test packet.

The delay command configures the delay metric (minimum, maximum, or average) that is used for comparison against any configured thresholds. This metric is the same for both types of measurement windows, the sample-window and aggregate-sample-window.

The unidirectional-measurement specifies the method used to compute the unidirectional delay. If the clock synchronization between nodal clocks used by the OAM timestamp function is not synchronized to near exact accuracy, the derived option must be used. Specifying this option calculates the unidirectional measurement using the roundtrip delay divided by two computation. If synchronization can meet near exact accuracy, the actual option can be used. Specifying this option calculates the forward delay using the forward direction timestamps, T2-T1 computation.

When the operational state of the link measurement test transitions to down, the OAM function instructs the routing engine to clear the last reported delay value at the expiration of the last-reported-delay-hold. A previously reported delay is considered valid for the duration of this period and is cleared if the timer reaches zero. If the operational state returns to up before the timer expires, no action is taken to clear the previous value. The counter is reset to the configured value, waiting for the next operational down event.

The operation state for the interface delay test is determined by administrative actions and system events. The administrative events that determine the operational state are:

• administratively disabling the measurement template associated with the interface

• administratively disabling the active IP protocol that is being used to generate the test packet under the config>router>interface>if-attribute>delay>dynamic-delay context

The resource issue system events that drive the operational state are:

• unavailability of the UDP port

• internal errors

The aging timer does not start a count to zero for failure conditions that do not affect the interface delay test operational state. The delay measurement last reported is maintained when conditions external to the interface delay test, such as fault conditions on the port, IP interface, routing changes, and so on, occur. If the last-reported-delay-timer is set to zero, previously reported delay values from that test are cleared when the operational state changes to down without any additional time.

The collection and reporting parameters define the length of the sample-window and aggregate-sample-window and the thresholds that trigger reporting. Two measurement windows are provided to support use cases that require a reporting hierarchy. Both measurement windows include the same configuration options. The threshold values determine when the measurement window is able to update the reported delay value.

The measurement windows use the multiplier command to determine the length of time that the measurement window remains open. The sample window length is multiples of the interval. This window stores the results of individual test probes for a total length of the interval multiplied by the multiplier value. The aggregate sample window multiplier length is the number of sample windows. This window stores the number of results passed from individual sample windows. In the aggregate sample window, the minimum, maximum, and average calculations are based on the results received from the sample window. For example, if the delay metric of interest is the average, the aggregate sample is a collection of averages passed from the sample window. The reporting in the aggregate sample window is as follows.

• The minimum is the minimum value for all the averages received.

• The maximum is the maximum value from all the averages received.

• The average is the average of all the averages received.

The comparison to thresholds and reporting decisions occurs at the end of the measurement window if it completes without termination and is deemed integral based on the window-integrity command configuration. Integrity is a percentage-based calculation that determines the number of samples that must be present in the measurement window for that window to be considered integral. If the number of samples in the window equals or exceeds the number of required samples, the result produced is treated as representative and follows normal post-measurement window processing. However, if the number of samples in the window does not achieve integrity, the result is not considered representative and is only recorded for historical purposes, but is otherwise ignored and not processed. By default, integrity checking is disabled and all results from a measurement window are treated as integral and compared to the configured thresholds.

There are two types of thresholds:

• a microsecond increase or decrease, configured using the absolute command

• a percentage increase or decrease, configured using the relative command

Thresholding compares the measurement window result to the delay measurement last reported at the end of the successful (completed) measurement window. Reporting is on a per-threshold, per-measurement window basis. If multiple thresholds are reached for a completed measurement window, only one threshold triggers an update to the routing engine. The reporting trigger is recorded with a structure of <Window‟Threshold”threshold>. For example, SampleThrehsoldAbsolute indicates that the absolute threshold in the sample window triggered the report. The report is accompanied by a timestamp and last reported value. When a sample window triggers a new delay measurement, the current aggregate sample window is restarted, preempting any possible reporting from the aggregate sample window. This allows both measurement window types to use the delay measurement last reported as the new benchmark.

Configuration of the measurement windows depends on the specific solution requirements. The two measurement windows collect information regardless of configured thresholds. Both types of measurement windows support their own threshold and integrity configuration. By default, thresholds for both measurement windows are disabled; that is, neither window can report any values to the routing engine.

The protocol parameters influence the format of the test packet, processing, QoS handling, IPv6 discovery, and which influences the return path.

TWAMP Light, also called Simple Two-way Activation Monitoring Protocol (STAMP), is the test packet used to gather IP link measurement delay. The link measurement request source is the session-sender.

TWAMP Light requires the explicit configuration of a reflector on the peer. For SR OS, TWAMP Light reflectors are configured in the config>router>twamp-light> reflector context. The reflector is referred to as the session-reflector, the responder to the request.

The session-sender and the session-reflector must agree on the UDP port used to identify TWAMP Light test packets. The SR OS configuration of the session-sender (configured using the dest-udp-port command) and session-reflector (configured using the udp-port command) must match.

The TWAMP Light test packet was first introduced to support the Network Time Protocol (NTP) encoding of the timestamp in the packet. Updates since the initial standardization of TWAMP Light supports the use of the truncated Precision Time Protocol (PTP) timestamp format. A bit in the TWAMP Light test packet header is repurposed to indicate the timestamp format encoded by the session-sender and the session-reflector. This change leads to some interoperability considerations. The timestamp format should be consistent with the session-sender and session-reflector behavior. The link measurement session-sender can be configured to encode NTP (default) or PTP and set the ‟z-bit” in the Error Estimate field accordingly. This bit indicates the timestamp format carried in the packet. If the session-reflector sets the ‟z-bit” in the Error Estimate field to indicate the timestamp format of the reply, the link measurement session-sender can perform the necessary conversion (format and epoch) to produce the correct results. However, if the session-reflector only reflects the original ‟z-bit” it received from the session-sender and uses a different timestamp format in the packet, the delay calculations are not reliable because of the misinterpretation of the returned timestamp format. SR OS session-reflectors running Release 21.5 and earlier always reflect the ‟z-bit” received from the session-sender. Regardless of the ‟z-bit”, these session-reflectors always encode an NTP timestamp format in the packet. When these session-reflectors receive a TWAMP Light test packet with the PTP timestamp format, there is a mismatch between the actual timestamp format and the timestamp it has encoded. There is no mechanism for the session-reflector to detect this mismatch and report the correct delay. To ensure accurate delay measurements, any session-sender sending TWAMP Light test packets to an SR OS TWAMP Light reflector that is running Release 21.5 and earlier, must use a timestamp format of NTP. Release 21.7 session-reflectors reply in kind for the timestamp format and properly set the timestamp format bit to match the timestamp encoded by the session-reflector.

IPv6 packets arriving with a UDP checksum of zero are discarded. However, recent work in the IETF is suggesting that selected protocols may register on the local router to accept and process IPv6 packets with a UDP checksum of zero. To provide interoperability, the allow-ipv6-udp-checksum-zero command allows the session-sender and the session-reflector to process IPv6 TWAMP Light test packets that arrive with a UDP checksum of zero. This is specific to the link measurement template session-sender and session-reflector and only for the specific UDP ports for TWAMP Light test packets.

By default, the TWAMP light reflection and the base TWAMP Light session-reflectors use routing to return the response packet to the session-sender. There are instances when it may be beneficial to be selective about the IP interface used to return the packet. For example, when multiple tests are executed on different interfaces between the same pair of nodes, and using non-directly connected interface addresses, and ECMP exists between the two nodes and the unidirectional-measurement actual is used. In this case, the return-path link command can be configured under the measurement-template twamp-light context. This includes the return path TLV and link sub TLV in the test packet. This configuration instructs the session reflector to send the response out the same IP interface on which it was received. The destination IP address for the response packet must be installed in the forwarding table and reachable from that interface. If the routing engine determines that the prefix is not reachable from that interface the response packet is dropped at the reflector.

SR OS supports the configuration modification of active measurement templates. That is, administratively disabling a measurement template that IP interfaces are actively referencing is not required. Modifying existing parameters causes interface delay tests that were referencing the modified template to terminate the current sample and aggregate measurement windows, and to start new measurement windows using the updated template parameters. The previous historical results are maintained, but the State field of the measurement window coinciding with the change indicates ‟Terminated”. Changing the description or the last-reported-delay-hold configuration does not cause a termination of the current sample and aggregate measurement windows.

A measurement template cannot be removed if interfaces are referencing that template.

The following show commands are available to display the link measurement templates:

• The show>test-oam>link-measurement measurement-template reports the measurement templates and the number of total and active interface references.

• The show>test-oam>link-measurement measurement-template-using command reports the measurement template, associated router interfaces and the protocols.

• The show>test-oam>link-measurement measurement-template template-name command reports the specific measurement template and the associated configuration parameters, with the number of active interfaces and total references to this templates.

To enable dynamic measurements for the interface, the user must configure a link measurement template and enable the test protocol using the ipv4 or ipv6 command. The link measurement template does not include interface-specific requirements, such as the IP protocol encapsulating the test packet or IP source and destination addressing. It is possible to enable the IPv4 or IPv6 protocol under the dynamic>twamp-light context without including any source or destination information.

When the IPv4 protocol is enabled with no addressing configured, the source address is automatically assigned to the primary IPv4 address of the IP interface. The destination address is automatically assigned if the primary IPv4 address has a prefix length of 30 or 31. In other cases, such as shorter prefix lengths or unnumbered interfaces, the destination address cannot be resolved and must be configured manually. The source and destination commands take precedence over the auto-assigned addressing; the IPv4 addresses must be unicast.

IPv4 auto-assigned addressing is not updated for operationally up interface delay tests when the IP addressing associated with that interface is changed. Nokia suggest the following options to update the auto-assigned addressing.

• Administratively disable and enable the protocol used for the interface delay test.

• Disable and enable the IP interface under which the IP address has changed.

When the IPv6 protocol is enabled without any source address, the system uses the link-local address associated with the interface as the source. If there is no destination address configuration, the destination discovery process is initiated if the associated measurement-template assigned to this interface has configure test-oam link-measurement measurement-template twamp-light ipv6-destination-discovery enabled.

The source and destination can be globally routable unicast addresses of the link identifying the directly-connected peers or the link local addresses connecting the peers. The link local address must follow the format fe80::/64 as described in RFC 4291, IP Version 6 Addressing Architecture.

TWAMP Light test packets consult the routing table to determine how to reach the destination. The test should be configured to use local IP interface source and directly connected IP peer interface destination addressing to ensure the packet egresses and returns over the same IP interface. The destination must be reachable from the IP interface where the interface delay test is configured. Using indirect IP addressing, such as unnumbered interfaces, does not guarantee that the measurement is reporting the delay for the expected interface.

Only one protocol, IPv4 or IPv6, can be enabled for an interface delay test at any time.

Interfaces defined as loopback do not support interface delay tests and are an invalid interface type. The configuration exists under these interfaces, but a detectable transmission error prevents the sending of packets.

The system interface does not support interface delay tests and the configuration is hidden.

When the link measurement template is assigned to an IP interface, the audit process determines the operational state of the test. The interface delay test transitions to operationally up if the following conditions are met:

• The associated measurement template is administratively enabled.

• There is an administratively enable test protocol, configured using the ipv4 or ipv6 command.

• The system resources are available to start the test.

Further validation determines if there are any underlying conditions that are considered detectable transmission errors, which are listed in Detectable transmission errors .

When all audit conditions successfully pass, the delay collection begins. When no thresholds are configured, the test collects delay information as history, but without at least one configured threshold value, reporting updates to the routing engine are disabled. If at least one threshold is configured, the interface enters the first report phase. Because no previous delay value has been reported, the first measurement window with a configured threshold that completes with integrity triggers the delay measurement report. After this benchmark is set, all subsequent thresholds use the delay measurement last reported as the comparison.

Active interface delay tests retain 50 sample windows and 20 aggregate sample windows in history. The current measurement windows and historical results are not maintained across CPM switchovers. The delay measurement last reported is maintained after a CPM switchover to retain the baseline. The interface does not enter the first reporting phase following a CPM switchover.

Several states exist to indicate the state of the measurement window:

InProgress

The measurement window is open and collecting results.

Completed

This state indicates natural completion of the delay test.

Terminated

A configuration change to the measurement template being referenced, or an administrative action or system event caused the operational state to change to down, consequently preempting and causing an abnormal termination.

SwReported

The sample window has triggered a delay measurement last report.

AswReported

The aggregate sample window has triggered a delay measurement last report.

SR OS supports the configuration of static and dynamic delay measurement, and provides a configuration parameter to determine precedence. The dynamic delay measurements use the link measurement templates and interface delay test packets to gather results. The static delay is a configured value. Both static delay and dynamic delay can be configured under the same interface. Both are reported to the routing engine based on their own rules. The routing engine must be informed on how to interpret this condition and which metric to advertise. The delay selection, configured using the delay-selection command, provides four options to customize the handling. The configuration options allow for only one to be considered (using the static or dynamic options) or which is to be preferred should both exist (using the static-preferred or dynamic-preferred options). There may be an amount of time between the interface initialization and the reporting of a valid dynamic delay value. This case may require some deployments to configure a static delay value to fill the time gap while waiting for the link measurement first report. In this case, preferring dynamic allows the routing engine to advertise the static value until the dynamic delay report is made.

The user can use show commands to display the link measurement templates.

The show test-oam link-measurement interface interface-name [detail | aggregate | sample debug-counters] command reports the interface-specific delay test information, such as operational data, reporting information, the historical results for sample and aggregate sample windows, and a count of unexpected conditions for response packets.

The show test-oam link-measurement interfaces command reports a list of all interfaces that are configured with link-measurement. The report includes all the basic operational summaries such as the interface name, operational state, protocol, errors, reporting, delay metric of interest, last delay, and the timestamp of the last delay.

config>log# info
----------------------------------------------
        file-id 1
            description "OAM PM XML file Paramaters"
            location cf2:
            rollover 10 retention 2
        exit
        accounting-policy 1
            description "Default OAM PM Collection Policy for 15-min Bins"
            record complete-pm
            collection-interval 5
            to file 1
            no shutdown
        exit
        log-id 1
        exit
----------------------------------------------

config>eth-cfm# info
----------------------------------------------
        domain 12 format none level 2
            association 4 format string name "vpls4-0000001"
                bridge-identifier 4
                exit
                ccm-interval 1
                remote-mepid 30
            exit
        exit

config>service>vpls# info
----------------------------------------------
            description "OAM PM Test Service to v30"
            stp
                shutdown
            exit
            sap 1/1/10:4.* create
                eth-cfm
                    mep 28 domain 12 association 4 direction up
                        ccm-enable
                        mac-address 00:00:00:00:00:28
                        no shutdown
                    exit
                exit
            exit
            sap 1/2/1:4.* create
            exit
            no shutdown

config>oam-pm#info detail
----------------------------------------------- 
        bin-group 2 fd-bin-count 10 fdr-bin-count 2 ifdv-bin-count 10 create
            no description
            bin-type fd
                bin 1
                    lower-bound 1000
                exit
                bin 2
                    lower-bound 2000
                exit
                bin 3
                    lower-bound 3000
                exit
                bin 4
                    lower-bound 4000
                exit
                bin 5
                    lower-bound 5000
                exit
                bin 6
                    lower-bound 6000
                exit
                bin 7
                    lower-bound 7000
                exit
                bin 8
                    lower-bound 8000
                exit
                bin 9
                    lower-bound 10000
                exit
            exit
            bin-type fdr
                bin 1
                    lower-bound 5000
                exit
            exit
            bin-type ifdv
                bin 1
                    lower-bound 100
                exit
                bin 2
                    lower-bound 200
                exit
                bin 3
                    lower-bound 300
                exit
                bin 4
                    lower-bound 400
                exit
                bin 5
                    lower-bound 500
                exit
                bin 6
                    lower-bound 600
                exit
                bin 7
                    lower-bound 700
                exit
                bin 8
                    lower-bound 800
                exit
                bin 9
                    lower-bound 1000
                exit
            exit
            no shutdown
        exit
        session "eth-pm-service-4" test-family Ethernet session-
type proactive create
            bin-group 2
            no description
            meas-interval 15-mins create
                no accounting-policy
                boundary-type clock-aligned
                clock-offset 0
                intervals-stored 32
            exit
            Ethernet
                dest-mac 00:00:00:00:00:30
                priority 0
                source mep 28 domain 12 association 4
                dmm test-id 10004 create
                    data-tlv-size 1000
                    interval 1000
                    no test-duration
                    no shutdown
                exit
                slm test-id 10004 create
                    data-tlv-size 1000
                    flr-threshold 50
                    no test-duration
                    timing frames-per-delta-t 10 consec-delta-t 10 interval 100 
                           chli-threshold 4
                    no shutdown
                exit
            exit
        exit

show oam-pm bin-group
-------------------------------------------------------------------------------
Configured Lower Bounds for Delay Measurement (DMM) Tests, in microseconds
-------------------------------------------------------------------------------
Group Description                    Admin Bin     FD(us)    FDR(us)   IFDV(us)
-------------------------------------------------------------------------------
1     OAM PM default bin group (not*    Up   0          0          0          0
                                             1       5000       5000       5000
                                             2      10000          -          -
-------------------------------------------------------------------------------
2                                       Up   0          0          0          0
                                             1       1000       5000        100
                                             2       2000          -        200
                                             3       3000          -        300
                                             4       4000          -        400
                                             5       5000          -        500
                                             6       6000          -        600
                                             7       7000          -        700
                                             8       8000          -        800
                                             9      10000          -       1000
-------------------------------------------------------------------------------
-------------------------------------------------------------------------------
* indicates that the corresponding row element may have been truncated.

show oam-pm bin-group 2
-------------------------------------------------------------------------------
Configured Lower Bounds for Delay Measurement (DMM) Tests, in microseconds
-------------------------------------------------------------------------------
Group Description                    Admin Bin     FD(us)    FDR(us)   IFDV(us)
-------------------------------------------------------------------------------
2                                       Up   0          0          0          0
                                             1       1000       5000        100
                                             2       2000          -        200
                                             3       3000          -        300
                                             4       4000          -        400
                                             5       5000          -        500
                                             6       6000          -        600
                                             7       7000          -        700
                                             8       8000          -        800
                                             9      10000          -       1000
------------------------------------------------------------------------------- 

show oam-pm bin-group-using
=========================================================================
OAM Performance Monitoring Bin Group Configuration for Sessions
=========================================================================
Bin Group       Admin   Session                            Session State
-------------------------------------------------------------------------
2               Up      eth-pm-service-4                             Act
-------------------------------------------------------------------------
========================================================================= 

show oam-pm bin-group-using bin-group 2
=========================================================================
OAM Performance Monitoring Bin Group Configuration for Sessions
=========================================================================
Bin Group       Admin   Session                            Session State
-------------------------------------------------------------------------
2               Up      eth-pm-service-4                             Act
-------------------------------------------------------------------------
========================================================================= 

show oam-pm sessions test-family Ethernet
============================================================================
OAM Performance Monitoring Session Summary for the Ethernet Test Family
============================================================================
Session                          State   Bin Group   Sess Type   Test Types
----------------------------------------------------------------------------
eth-pm-service-4                   Act           2   proactive      DMM SLM
============================================================================ 

show oam-pm session "eth-pm-service-4" all
-------------------------------------------------------------------------------
Basic Session Configuration
-------------------------------------------------------------------------------
Session Name      : eth-pm-service-4
Description       : (Not Specified)
Test Family       : Ethernet            Session Type       : proactive
Bin Group         : 2
-------------------------------------------------------------------------------

-------------------------------------------------------------------------------
Ethernet Configuration
-------------------------------------------------------------------------------
Source MEP        : 28                  Priority           : 0
Source Domain     : 12                  Dest MAC Address   : 00:00:00:00:00:30
Source Assoc'n    : 4
-------------------------------------------------------------------------------

-------------------------------------------------------------------------------
DMM Test Configuration and Status
-------------------------------------------------------------------------------
Test ID           : 10004               Admin State        : Up
Oper State        : Up                  Data TLV Size      : 1000 octets
On-Demand Duration: Not Applicable      On-Demand Remaining: Not Applicable
Interval          : 1000 ms
-------------------------------------------------------------------------------

-------------------------------------------------------------------------------
SLM Test Configuration and Status
-------------------------------------------------------------------------------
Test ID           : 10004               Admin State        : Up
Oper State        : Up                  Data TLV Size      : 1000 octets
On-Demand Duration: Not Applicable      On-Demand Remaining: Not Applicable
Interval          : 100 ms
CHLI Threshold    : 4 HLIs              Frames Per Delta-T : 10 SLM frames
Consec Delta-Ts   : 10                  FLR Threshold      : 50%
-------------------------------------------------------------------------------

-------------------------------------------------------------------------------
15-mins Measurement Interval Configuration
-------------------------------------------------------------------------------
Duration          : 15-mins             Intervals Stored   : 32
Boundary Type     : clock-aligned       Clock Offset       : 0 seconds
Accounting Policy : none
-------------------------------------------------------------------------------

-------------------------------------------------------------------------------
Configured Lower Bounds for Delay Measurement (DMM) Tests, in microseconds
-------------------------------------------------------------------------------
Group Description                    Admin Bin     FD(us)    FDR(us)   IFDV(us)
-------------------------------------------------------------------------------
2                                       Up   0          0          0          0
                                             1       1000       5000        100
                                             2       2000          -        200
                                             3       3000          -        300
                                             4       4000          -        400
                                             5       5000          -        500
                                             6       6000          -        600
                                             7       7000          -        700
                                             8       8000          -        800
                                             9      10000          -       1000
------------------------------------------------------------------------------- 

show oam-pm statistics session "eth-pm-service-4" dmm meas-interval 15-
mins interval-number 2 all
------------------------------------------------------------------------------
Start (UTC)       : 2014/02/01 10:00:00          Status          : completed
Elapsed (seconds) : 900                          Suspect         : no
Frames Sent       : 900                          Frames Received : 900
------------------------------------------------------------------------------

----------------------------------------------------------------------
Bin Type     Direction     Minimum (us)   Maximum (us)   Average (us)
----------------------------------------------------------------------
FD           Forward                  0           8330            712
FD           Backward               143          11710           2605
FD           Round Trip            1118          14902           3111
FDR          Forward                  0           8330            712
FDR          Backward               143          11710           2605
FDR          Round Trip               0          13784           1990
IFDV         Forward                  0           8330            431
IFDV         Backward                 1          10436            800
IFDV         Round Trip               2          13542           1051
----------------------------------------------------------------------

---------------------------------------------------------------
Frame Delay (FD) Bin Counts
---------------------------------------------------------------
Bin      Lower Bound       Forward      Backward    Round Trip
---------------------------------------------------------------
0               0 us           624            53             0
1            1000 us           229           266           135
2            2000 us            29           290           367
3            3000 us             4           195           246
4            4000 us             7            71            94
5            5000 us             5            12            28
6            6000 us             1             7            17
7            7000 us             0             1             5
8            8000 us             1             4             3
9           10000 us             0             1             5
---------------------------------------------------------------

---------------------------------------------------------------
Frame Delay Range (FDR) Bin Counts
---------------------------------------------------------------
Bin      Lower Bound       Forward      Backward    Round Trip
---------------------------------------------------------------
0               0 us           893           875           873
1            5000 us             7            25            27
---------------------------------------------------------------

---------------------------------------------------------------
Inter-Frame Delay Variation (IFDV) Bin Counts
---------------------------------------------------------------
Bin      Lower Bound       Forward      Backward    Round Trip
---------------------------------------------------------------
0               0 us           411           162            96
1             100 us           113           115           108
2             200 us            67            84            67
3             300 us            56            67            65
4             400 us            36            46            53
5             500 us            25            59            54
6             600 us            25            27            38
7             700 us            29            34            22
8             800 us            41            47            72
9            1000 us            97           259           325
--------------------------------------------------------------- 

show oam-pm statistics session "eth-pm-service-4" slm meas-interval 15-
mins interval-number 2
------------------------------------------------------------------------------
Start (UTC)       : 2014/02/01 10:00:00          Status          : completed
Elapsed (seconds) : 900                          Suspect         : no
Frames Sent       : 9000                         Frames Received : 9000
------------------------------------------------------------------------------

------------------------------------------------------
                    Frames Sent       Frames Received
------------------------------------------------------
Forward                    9000                  9000
Backward                   9000                  9000
------------------------------------------------------

-------------------------------------------
Frame Loss Ratios
-------------------------------------------
             Minimum    Maximum    Average
-------------------------------------------
Forward       0.000%     0.000%     0.000%
Backward      0.000%     0.000%     0.000%
-------------------------------------------

-------------------------------------------------------------------------------
Availability Counters (Und = Undetermined)
-------------------------------------------------------------------------------
           Available   Und-Avail Unavailable Und-Unavail        HLI       CHLI
-------------------------------------------------------------------------------
Forward          900           0           0           0          0          0
Backward         900           0           0           0          0          0
------------------------------------------------------------------------------- 

show oam-pm statistics session "eth-pm-service-4" dmm meas-interval raw
------------------------------------------------------------------------------
Start (UTC)       : 2014/02/01 09:43:58          Status          : in-progress
Elapsed (seconds) : 2011                         Suspect         : yes
Frames Sent       : 2011                         Frames Received : 2011
------------------------------------------------------------------------------

----------------------------------------------------------------------
Bin Type     Direction     Minimum (us)   Maximum (us)   Average (us)
----------------------------------------------------------------------
FD           Forward                  0          11670            632
FD           Backward                 0          11710           2354
FD           Round Trip            1118          14902           2704
FDR          Forward                  0          11670            611
FDR          Backward                 0          11710           2353
FDR          Round Trip               0          13784           1543
IFDV         Forward                  0          10027            410
IFDV         Backward                 0          10436            784
IFDV         Round Trip               0          13542           1070
----------------------------------------------------------------------

---------------------------------------------------------------
Frame Delay (FD) Bin Counts
---------------------------------------------------------------
Bin      Lower Bound       Forward      Backward    Round Trip
---------------------------------------------------------------
0               0 us          1465           252             0
1            1000 us           454           628           657
2            2000 us            62           593           713
3            3000 us             8           375           402
4            4000 us            11           114           153
5            5000 us             7            26            41
6            6000 us             2            10            20
7            7000 us             0             2             8
8            8000 us             1            10            11
9           10000 us             1             1             6
---------------------------------------------------------------

---------------------------------------------------------------
Frame Delay Range (FDR) Bin Counts
---------------------------------------------------------------
Bin      Lower Bound       Forward      Backward    Round Trip
---------------------------------------------------------------
0               0 us          2001          1963          1971
1            5000 us            11            49            41
---------------------------------------------------------------

---------------------------------------------------------------
Inter-Frame Delay Variation (IFDV) Bin Counts
---------------------------------------------------------------
Bin      Lower Bound       Forward      Backward    Round Trip
---------------------------------------------------------------
0               0 us           954           429           197
1             100 us           196           246           197
2             200 us           138           168           145
3             300 us           115           172           154
4             400 us            89            96           136
5             500 us            63            91           108
6             600 us            64            53            89
7             700 us            61            55            63
8             800 us           112            82           151
9            1000 us           219           619           771
--------------------------------------------------------------- 

show oam-pm statistics session "eth-pm-service-4" slm meas-interval raw
------------------------------------------------------------------------------
Start (UTC)       : 2014/02/01 09:44:03          Status          : in-progress
Elapsed (seconds) : 2047                         Suspect         : yes
Frames Sent       : 20470                        Frames Received : 20469
------------------------------------------------------------------------------

------------------------------------------------------
                    Frames Sent       Frames Received
------------------------------------------------------
Forward                   20329                 20329
Backward                  20329                 20329
------------------------------------------------------

-------------------------------------------
Frame Loss Ratios
-------------------------------------------
             Minimum    Maximum    Average
-------------------------------------------
Forward       0.000%     0.000%     0.000%
Backward      0.000%     0.000%     0.000%
-------------------------------------------

-------------------------------------------------------------------------------
Availability Counters (Und = Undetermined)
-------------------------------------------------------------------------------
           Available   Und-Avail Unavailable Und-Unavail        HLI       CHLI
-------------------------------------------------------------------------------
Forward         2033           0           0           0          0          0
Backward        2033           0           0           0          0          0
------------------------------------------------------------------------------- 

The monitor command can be used to automatically update the statistics for the raw measurement interval.