Setting Up CFM
  • 25 Sep 2024
  • 20 Minutes to read
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Setting Up CFM

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Article summary

The steps required to set up Connectivity Fault Management (CFM) are:

  • Set up Maintenance Domains (MD).
  • Set up Maintenance Associations (MA), also known as Maintenance Entity Groups (MEG).
  • Set up Maintenance association End Points (MEP).

Viewing CFM Summary

The CFM summary can be displayed whether the remote device context has been set or not.

If the remote device context has not been set, the CFM library version for all remote devices will be displayed. If the remote device context has been set, then only the information related to the selected device will be displayed.

To view CFM summary

  1. Access the page SOAM ▶ CFM ▶ Summary.
    A list of all CFM instances and their settings is displayed.

For more information on specific parameters, refer to the following table.

CFM Summary (SOAM ▶ CFM ▶ Summary)

ParameterDescription
Remote deviceRemote device name. This is user configurable. By default, the remote device name is the device's serial number.
LibrarySOAM library version of the remote-device (either v1 or v2)
#DomainMaintenace Domain
#MaMaintenance association
#MepMaintenance association end point
#PLPacket loss
#DMMDelay measurements
#SLMSynthetic Loss Measurements
DMMReflector Enabled or Disabled

Configuring the CFM library

The CFM library can be configured (either v1 or v2) to be used for the selected remote device.


Note: The remote-device context has to be set prior to configuring the CFM library (or any CFM configuration for v2 library). For the v1 library, context is not required and can be set at "None".

To configure the CFM library

  1. Access the page SOAM ▶ CFM ▶ Summary.
    A list of all CFM instances and their settings is displayed.

  2. Click the Library of an exiting CFM instance to display the SOAM library configuration window.

  3. Select the library version then click Apply.

For more information on specific parameters, refer to the following table.

CFM Stack (SOAM ▶ CFM ▶ Summary)

ParameterDescription
Remote deviceRemote device name.
LibraryLibrary version of the selected remote-device (either v1 or v2).

The SOAM library version (v1) supports one MEP per device. No Packet Loss, DMM and SLM. It also support the DMM reflection.

The v2 library supports multiple MEP, DMM, SLM and Packet loss. On demand DMM reflection without MEP validation is not supported.

Viewing CFM Instances

To view CFM instances

  1. Access the page SOAM ▶ CFM ▶ Stack.
    A list of all CFM instances and their settings is displayed.

For more information on specific parameters, refer to the following table.

CFM Stack (SOAM ▶ CFM ▶ Stack)

ParameterDescription
PortThe port on which MEPs or MIPs have been configured
VIDThe VLAN ID to which the Maintenance Point is attached, or 0, if there is no VLAN ID
LevelThe MD level (or MEG level) of the Maintenance Point Possible values: 0-7
DirThe direction in which the MEP or MIPs faces on the port
MD idxThe index of the Maintenance Domain with which the MEP or MIP is associated
MA idxThe index of MA (or MEG) with which the MEP or MIP is associated
MEPIDThe MEPID of the MEP or MIP (MEPID of MIP is 0)
MAC AddressThe MAC address of the Maintenance Point

There are eight pseudo MDs defined by default, one for each level, named Y.1731 level 0 to Y.1731 level 7. These MDs exist only to simplify the integration of MEGs for Y.1731 with the CFM MIB, which requires MDs. The Y.1731 protocol uses MEG-IDs, which are MAIDs without an MD name. User interfaces show the pseudo MD name, but this name is not included in the Y.1731 CCM's MEG-ID.


Note: Pseudo MDs cannot be deleted from the system.

Setting Up Maintenance Domains (MD)

To set up a Maintenance Domain

  1. Access the page SOAM ▶ CFM ▶ MD.
    A listing of all existing Maintenance Domains is displayed.

  2. Click the Add button to create a new Maintenance Domain.
    You can also click the Name of an existing Maintenance Domain to either Apply, Reset or Delete it.

  3. Complete the required fields, then click Apply.

For more information on specific parameters, refer to the following table.

Maintenance Domain (SOAM ▶ CFM ▶ MD)

ParameterDescription
Name FormatThe format of the Maintenance Domain name.

The only supported value is:

  • Character String: RFC 2579 display string, except that the character codes 0–31 (decimal) are not used.
  • DNS like Name format: Domain Name-like string, a globallyunique text string derived from a DNS name.

The name format must be the same for the other end points.

Name

MD Name

Unique name for the maintenance domain.
LevelMaintenance Level of the Maintenance Domain.

Possible values: 0-7

Deleting a Maintenance Domain (MD)

To delete a maintenance domain

  1. Access the page SOAM ▶ CFM ▶ MD.
    A listing of all existing Maintenance Domains is displayed.

  2. Click the name of the MD instance to be deleted.

  3. Click Delete.


    CAUTION: Deleting an MD will also delete all instances (e.g. MA/MEG) that use this MD.

Setting Up Maintenance Associations (Maintenance Entity Groups)

Before setting up an MA (also referred to as a MEG), you must first set up the MD to which you want the MA/MEG to belong. Maintenance Associations (MA) are discussed in IEEE 802.1ag; Maintenance Entity Groups (MEG) are discussed in ITU-T Y.1731.

To set up a Maintenance Association or Maintenance Entity Group

  1. Access the page SOAM ▶ CFM ▶ MA/MEG.
    A listing of all Maintenance Associations / Maintenance Entity Groups is displayed.

  2. Click the Add button to add a new Maintenance Association or Maintenance Entity Group or click the Name of an existing Maintenance Association or Maintenance Entity Group to apply, reset or delete it.

  3. Complete the required fields, then click Apply.

For more information on specific parameters, refer to the following table.

Maintenance Association (SOAM ▶ CFM ▶ MA/MEG)

ParameterDescription
MA/MEG Index

Index

Unique index value assigned to the Maintenance Association or Maintenance Entity Group
MD IndexThe index value assigned to the Maintenance Domain for this MEP
MD NameThe name of the Maintenance Domain for this MEP
Name FormatThe format of the Maintenance Association or Maintenance Entity Group name

Possible values are:

  • String: RFC 2579 display string
  • ICC-Based: ITU Carrier Code format
Name

MA/MEG Name

The name of this Maintenance Association or Maintenance Entity Group
LevelMaintenance Level of the Maintenance Association or Maintenance Entity Group Possible values: 0-7
CCM intervalThe required time interval between Continuity Check Messages (CCM). Expressed in milliseconds.

Default: 1000 milliseconds

VCA-VLAN NameThe VCA-VLAN Name refers to the Virtual Connection defined by the VCA-VLAN configuration.
VLAN-TPThe reference point (VLAN-TP) within the VCA-VLAN, on which the MA/MEG is associated. Values:
  • VLAN-TP-A
  • VLAN-TP-A-1
  • VLAN-TP-A-2
  • VLAN-TP-A-3
  • VLAN-TP-Z
  • VLAN-TP-Z-1
  • VLAN-TP-Z-2
  • VLAN-TP-Z-3
Use VCESelect this box to enable VCE for use. When enabled, another field is shown: VCE Name allowing you to select the VCE to use.

Note: This parameter is not configurable when using VCA-VLAN.

VCE NameType the name of the VCE you wish to use.

Note: This parameter is not configurable when using VCA-VLAN.

VLAN ID listA list of the VLANs associated with this Maintenance Association or Maintenance Entity Group.

If you leave the VLAN ID field empty, the association is not attached to a VLAN.

Remote MEP AutodiscoverySelect this box to enable the Remote MEP Auto-Discovery feature for this Maintenance Association or Maintenance Entity Group. When enabled, remote MEPs are automatically added to the MA/MEG as soon as the remote MEP's CCM message is received.

Note: You must manually refresh the page to view any remote MEPs that have been discovered since the page was initially loaded.

MEPID list

Sensor SFP 1G and Sensor Module 1G supports a list up to 100 MEPIDs.

A comma-separated list of all the MEPs that are associated with this Maintenance Association or Maintenance Entity Group.

Typically, when two MEP are added to a MA/MEG, it is usually because you are creating an E-Line type of service, based on a point-to-point EVC. In contrast, adding multiple MEP is for when you are creating an E-LAN type of service, based on a rooted multipoint EVC.

If the Remote MEP Auto-Discovery feature for this Maintenance Association or Maintenance Entity Group is enabled, the list of MEPIDs will be presented in numerical order, not the order in which the MEPs are discovered.

To delete a Maintenance Association (Maintenance Entity Group)

  1. Access the page SOAM ▶ CFM ▶ MA/MEG.
    A listing of all Maintenance Associations / Maintenance Entity Groups is displayed.
  2. Click the name of the Maintenance Association or Maintenance Entity Group to be deleted.
  3. Click Delete.


    CAUTION: Deleting a MA/MEG will also delete all instances (e.g. MEP) that use this MA/MEG.

Setting Up Maintenance Association End Points

Before setting up a MEP, you must first set up its MA/MEG. Maintenance association End Points (MEP) are discussed in IEEE 802.1ag.

To set up a Maintenance association End Point

  1. Access the page SOAM ▶ CFM ▶ MEP ▶ Configuration.
    A listing of all Maintenance association End Points is displayed.

  2. Click the Add button to add a new MEP or click the MEPID of an existing MEP to apply, reset or delete its settings.

  3. Complete the required fields, then click Apply.


    Note: Users can undo the current changes by clicking Reset to restore the values prior to making any changes. The Delete operation is described on the next page.

For more information on specific parameters, refer to the following table.

Maintenance association End Point (SOAM ▶ CFM ▶ MEP ▶ Configuration)

ParameterDescription
MEP IndexThe index value assigned to the Maintenance association End Point
MD IndexThe index value assigned to the Maintenance Domain for this MEP
MD NameThe name of the Maintenance Domain for this MEP
MAC addressThe MAC address of the maintenance domain
MA/MEG IndexThe index value of the maintenance association (or MEG) to associate with the MEP
MA/MEG NameThe name of the maintenance association (or MEG) to associate with the MEP
MEPIDMaintenance association End Point Identifier (MEPID) for this Maintenance association.

This value is an integer, unique to each MA, that identifies a specific MEP in CCM frames.

VCE portIf the MA/MEG is associated with a VCA-VLAN configuration or a VCE configuration (legacy), the checkbox is greyed-out, but it is automatically checked when you associate it with a MA/MEG. The user can not select this.
VCE NameThe name of the VCE that you wish to use
TPA pull-down menu with a limited selection: tp-a or tp-z. Select the desired terminal point.
PortThe port used by this MEP.

Note: This option only visible if the MA/MEG was created using a VCE.

DirectionThe direction in which the MEP faces on the Bridge port. Refer to IEEE802.1ag for more information.
  • Up: The MEP resides in a bridge that transmits CFM PDUs toward, and receives them from, the direction of the Bridge Relay Entity. Up MEP points toward the Bridge Relay Entity.
  • Down: The MEP resides in a Bridge that receives CFM PDUs from, and transmits them toward, the direction of the LAN. Down MEP points away from the Bridge Relay Entity.
MEP NameThe name of the Maintenance association End Point.
ActiveThe administrative state of the MEP:
  • Checked (Yes): The MEP is to function normally.
  • Unchecked (No): The MEP is to cease functioning.

Note: When deactivating a MEP, you must also deactivate all DMM, SLM and Frame Loss instances that use this MEP. Doing so will stop the unit from sending DMM and SLM frames and prevent the units from detecting unwanted alarms, such as CCM alarms.

CCI EnableIndicates whether or not the MEP generates CCM messages:
  • Checked (Enabled): The MEP generates CCM messages.
  • Unchecked (Disabled): The MEP does not generate CCM messages.
CCM Sequence NumberWhen enabled, a MEP transmits CCMs with a sequence number that increases by one for each CCM. When disabled, a MEP transmits CCMs with a sequence number set to zero.

Note: A peer MEP should have the sequence number enabled to allow a local MEP to perform CCM-based frame loss measurements.

Primary VID VLANThe Primary VLAN ID of the MEP. This is always one of the VLAN IDs assigned to the MEP's MA/MEG. The value 0 indicates that either the Primary VLAN ID is that of the MEP's MA/MEG, or that the MEP's MA/MEG is not associated with a VLAN ID.
CCM, LTM and CSF PriorityPriority parameter for CCMs, LTMs and CSFs transmitted by the MEP. The possible values are 0-7, with 7 being the highest value allowed to pass through the Bridge Port for any of this MEP's VLAN IDs.

Default value: 7 (highest priority)

Lowest Priority Defect AlarmLowest priority defect that is allowed to generate a CFM Fault Alarm.
Fault NotificationThe period of time for which defects must be present before a Fault
Alarm TimeAlarm is issued. Valid values are multiples of 100 milliseconds, e.g., 2100.
Fault Notification Reset TimeThe period of time for which defects must be absent before resetting a Fault Alarm. Valid values are multiples of 100 milliseconds, e.g., 2100.
CCM PriorityPriority parameter for CCM transmitted by the MEP. The possible values are 0-7, with 7 being the highest value allowed to pass through the Bridge Port for any of this MEP's VLAN IDs.

Default value: 7 (highest priority)

CSF EnableEnables this MEP to transmit Ethernet Client Signal Failure (ETHCSF) to its peer MEP upon the detection of a failure or defect event in the Ethernet client signal. That port should also be set up to perform EVC fault propagation. This feature works only on an Up Mep.

Note: ETH-CSF is not available using the V1 library and for ETH-CSF to cause the Fault to be Propagated requires that FP be enabled in the Port Configuration.

Note: A MA/MEG with more than two end points cannot be used.

EVC-FP enableWhen checked on an MEP instance, a Remote CCM defect causes a fault (link-down) to be propagated to the UNI port.

Note: This field only appears for supported modules. You must check CSF Enable to configure this field.

To delete a Maintenance association End Point

  1. Access the page SOAM ▶ CFM ▶ MEP ▶ Configuration.
    A listing of all Maintenance association End Points is displayed.

  2. Click the MEPID of the MEP to be deleted.

  3. Click Delete.

Viewing MEP Status

To view maintenance association end point (MEP) status

  1. Access the page SOAM ▶ CFM ▶ MEP ▶ Status.

    A listing of all MEPs is displayed, along with their status codes and details.

    The total number of MEPs found in the system is given in the lower left corner of the page, as well as the index values of the items currently displayed on-screen (for example, [1-25] of 54). Use the page navigation links in the lower-right corner of the page to move between the pages of results.

  2. (Optional) To limit the view to only certain MEPs, enter a value on which to filter, then click Search. You can filter by the MEP name, MEPID, Database, RDI or R-CCM status code value. If the MA/MEG was created using a VCA-VLAN/VCE, you can filter by the MEP Index, MEPID, Database, RDI, MAC, R-CCM, E-CCM, X-CCM, AIS, EPL, EDM, C-LOS, C-FDI, C-RDI, N-SLM and F-SLM status code values.


    Note: Enter an asterisk ( * ) as a wildcard to replace one or several characters.

For more information on specific codes, refer to the following table.

MEP Status (SOAM ▶ CFM ▶ MEP ▶ Status)

ParameterDescription
IndexIndex assigned to the Maintenance association End Point
NameThe name assigned to this Maintenance association End Point
MEPIDIdentifier for the Maintenance association End Point
DBLink to this MEP's database.
RDI

CCM RDI

The latest CCM received by this MEP from a remote MEP containing the Remote Defect Indication (RDI) bit

Possible values are Active (A) or Inactive (I).

MAC

MAC Status

The last CCM received by this MEP from a remote MEP indicates that the transmitting MEP's associated MAC is reporting an error status via the Port Status TLV or Interface Status TLV. Possible values are Active (A) or Inactive (I).
R-CCM

Remote CCM

Indicates whether the MEP is not receiving CCMs from a MEP in its configured list.

Possible values are Active (A) or Inactive (I).

E-CCM

Errored CCM

Indicates whether the MEP is receiving invalid CCM messages

Possible values are Active (A) or Inactive (I).

X-CCM

Cross-Connect CCM

Indicates whether the MEP is receiving CCM messages that could be coming from another MA

Possible values are Active (A) or Inactive (I).

AIS

Received AIS

Indicates whether Y.1731 Alarm Indication Signal (AIS) PDUs are being received

Possible values are Active (A) or Inactive (I).

EPL

Excessive Packet Loss

Indicates whether some packet loss measurement defect is Active (A) or Inactive (I) for that MEP
EDM

Excessive Delay

Indicates whether some delay measurement defect is Active (A) or Inactive (I) for that MEP
N-SLM

(Near end loss)

The Near-End Synthetic Loss Measurement indicates whether near-end synthetic loss messages are Active (A) or Inactive (I) for that MEP
F-SLM

(Far end loss)

The Far-End Synthetic Loss Measurement indicates whether farend synthetic loss messages are Active (A) or Inactive (I) for that MEP
C-LOS

Received C-LOS

Indicates that Y.1731 Client Signal Fail (CSF) Loss of Signal (LOS) PDUs are being received. Possible vales are Active (A) or Inactive (I).
C-FDI

Received C-FDI

Indicates that Y.1731 Client Signal Fail (CSF) Forward Defect Indication (FDI) PDUs are being received. Possible vales are Active (A) or Inactive (I).
C-RDI

Received C-RDI

Indicates that Y.1731 Client Signal Fail (CSF) Reverse Defect Indication (RDI) PDUs are being received. Possible vales are Active (A) or Inactive (I).

To view maintenance association end point (MEP) status

  1. Access the page SOAM ▶ CFM ▶ MEP ▶ Status.

    A listing of all MEPs is displayed, along with their status codes and details.

    The total number of MEPs found in the system is given in the lower left corner of the page, as well as the index values of the items currently displayed on-screen (for example, [1-25] of 54). Use the page navigation links in the lower-right corner of the page to move between the pages of results.

  2. (Optional) To limit the view to only certain MEPs, enter a value on which to filter, then click Search. You can filter by the MEP name, MEPID, Database, RDI or R-CCM status code value. If the MA/MEG was created using a VCA-VLAN/VCE, you can filter by the MEP Index, MEPID, Database, RDI, MAC, R-CCM, E-CCM, X-CCM, AIS, EPL, EDM, C-LOS, C-FDI, C-RDI, N-SLM and F-SLM status code values.


    Note: Enter an asterisk ( * ) as a wildcard to replace one or several characters.

For more information on specific codes, refer to the following table.

MEP Status (SOAM ▶ CFM ▶ MEP ▶ Status)

ParameterDescription
IndexIndex assigned to the Maintenance association End Point
NameThe name assigned to this Maintenance association End Point
MEPIDIdentifier for the Maintenance association End Point
DBLink to this MEP's database.
RDI

CCM RDI

The latest CCM received by this MEP from a remote MEP containing the Remote Defect Indication (RDI) bit

Possible values are Active (A) or Inactive (I).

MAC

MAC Status

The last CCM received by this MEP from a remote MEP indicates that the transmitting MEP's associated MAC is reporting an error status via the Port Status TLV or Interface Status TLV. Possible values are Active (A) or Inactive (I).
R-CCM

Remote CCM

Indicates whether the MEP is not receiving CCMs from a MEP in its configured list.

Possible values are Active (A) or Inactive (I).

E-CCM

Errored CCM

Indicates whether the MEP is receiving invalid CCM messages

Possible values are Active (A) or Inactive (I).

X-CCM

Cross-Connect CCM

Indicates whether the MEP is receiving CCM messages that could be coming from another MA

Possible values are Active (A) or Inactive (I).

AIS

Received AIS

Indicates whether Y.1731 Alarm Indication Signal (AIS) PDUs are being received

Possible values are Active (A) or Inactive (I).

EPL

Excessive Packet Loss

Indicates whether some packet loss measurement defect is Active (A) or Inactive (I) for that MEP
EDM

Excessive Delay

Indicates whether some delay measurement defect is Active (A) or Inactive (I) for that MEP
N-SLM

(Near end loss)

The Near-End Synthetic Loss Measurement indicates whether near-end synthetic loss messages are Active (A) or Inactive (I) for that MEP
F-SLM

(Far end loss)

The Far-End Synthetic Loss Measurement indicates whether farend synthetic loss messages are Active (A) or Inactive (I) for that MEP
C-LOS

Received C-LOS

Indicates that Y.1731 Client Signal Fail (CSF) Loss of Signal (LOS) PDUs are being received. Possible vales are Active (A) or Inactive (I).
C-FDI

Received C-FDI

Indicates that Y.1731 Client Signal Fail (CSF) Forward Defect Indication (FDI) PDUs are being received. Possible vales are Active (A) or Inactive (I).
C-RDI

Received C-RDI

Indicates that Y.1731 Client Signal Fail (CSF) Reverse Defect Indication (RDI) PDUs are being received. Possible vales are Active (A) or Inactive (I).

Viewing MEP Statistics

To view MEP statistics

  1. Access the page SOAM ▶ CFM ▶ MEP ▶ Statistics.
    A summary of statistics of all MEPs is displayed.

  2. Click any MEPID to view detailed statistics of this MEP.

For more information on specific parameters, refer to the following table.

MEP Statistics (SOAM ▶ CFM ▶ MEP ▶ Statistics)

ParameterDescription
Index

MEP Index

Index assigned to the Maintenance association End Point
MEPIDMaintenance association End Point Identifier
CCM Sent

CCM

Indicates the number of connectivity check messages sent by this MEP
CCM Received

CCM

Indicates the number of connectivity check messages received by this MEP
RDI Sent

CCM with RDI

Indicates the number of connectivity check messages sent by this MEP with the RDI bit set
RDI Received

CCM with RDI

Indicates the number of connectivity check messages received by this MEP with the RDI bit set
CCM Seq Error

CCM Received Sequence Errors

Indicates the total number of out-of-sequence CCMs received from all remote MEPs
DMR Priority

Mismatch

Indicates the total number of DMRs received whose VLAN priority value did not match that of the corresponding DMM.

Viewing the MEP Database

The MEP database gives you information about remote MEPs.

To view database information for MEPs

  1. Access the page SOAM ▶ CFM ▶ MEP ▶ Status.

  2. Click the MEP database identifier for which you want to view a summary.

  3. Click any MEPID to view detailed database information.

For more information on specific parameters, refer to the following table.

MEP Database (SOAM ▶ CFM ▶ MEP ▶ Status ▶ [Database])

ParameterDescription
MEPIDMaintenance association End Point identifier of the remote MEP whose information from the MEP Database is to be returned
StateThe operational state of the remote MEP IFF state machines

Possible values are:

  • Idle: If the local MEP is disabled, then all Remote MEP IDs in that MA/MEG will remain idle.
  • Start: MEP monitoring has started, but no CCMs have been received
  • Failed: CCM messages were not received, or received late
  • OK: Valid CCM messages have been received
RDIThe state of the RDI bit in the last received CCM.

Possible values are:

  • True: The RDI bit was set
  • False: The RDI bit was not set, no CCM message was received
Mac AddressThe MAC address of the remote MEP
R-CCMRemote CCM. Indicates whether the MEP is not receiving CCMs from a MEP in its configured list.
Latest Failed-OK TimeThe time at which the IFF Remote MEP state machine last entered either the failed or OK state
Port Status TLVThe value of the port status TLV received in the last CCM from the remote MEP (see Port Status TLV of 802.1ag for details)

Possible values are:

  • ---(none 0): No CCM was received or no port status TLV was received in the last CCM.
  • Blocked (1)
  • Up (2)
Interface Status TLVThe value of the interface status TLV received in the last CCM from the remote MEP (see Interface Status TLV of 802.1ag for details)

Possible values are:

  • ---(0): No CCM was received or no interface status TLV was received in the last CCM.
  • Up (1)
  • Down (2)
  • Testing (3)
  • Unknown (4)
  • Dormant (5)
  • Not Present (6)
  • Lower Layer Down (7)

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