Using Service OAM

Service OAM (SOAM) is a layer-2 protocol used for Connectivity Fault Management (CFM) and Performance Monitoring (PM) in a Carrier Ethernet Network (CEN) and encompasses the fault management and performance management capabilities of the Skylight performance element GT.
The following sections describe IEEE 802.1ag Service OAM and show how to set up your Metro Ethernet Network to perform end-to-end monitoring.

An overview of Service OAM is given below.

Overview of Service OAM

The diagram below shows a typical setup scenario for Service OAM.

Typical Setup Scenario for Service OAM

MEP vs. MIP

A Maintenance End Point (MEP) is a provisioned OAM reference point that can initiate and terminate proactive OAM frames and can initiate and react to diagnostic OAM frames. A MEP is represented by a “triangle” symbol, as shown in the OAM diagram below. A Point-to-Point EVC has two MEPs, one at each end-point of the ME (i.e. each UNI-N).

Each MEP has a direction, down or up:

• A Down MEP receives PDUs from the local interface and sends PDUs towards the local interface.
• An Up MEP receives PDUs from the relay entity and sends PDUs towards the relay entity.

A Maintenance Intermediate Point (MIP) is a provisioned OAM reference point that is capable of reacting to diagnostic OAM frames initiated by MEPs and does not initiate proactive or diagnostic OAM frames. A MIP is represented by a “circle” symbol, as shown in the Overview of Service OAM, in Using Service OAM. The number of MIPs in a Point-to-Point EVC or Multipoint EVC depends on the specific deployment.

MIPs are used for Fault Management.

Setting Up CFM

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).

Once these are set up, you can use Service OAM for performing the following fault management functions:

• Link Trace Messages. "Setting Up Link Trace Messages".
• Loopback Messages. "Setting Up Loopback Messages".

For viewing MEP information, see also Viewing MEP Status, Viewing the MEP Database, and Viewing MEP Statistics. You can also set up delay measurements, packet loss measurements and synthetic loss measurements.

If required, you can set up CFM defaults. "Setting Up CFM Default Values".

If required, you can configure the unit as a VSP reflector. "Setting Up VSP".

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)

Setting Up Maintenance Domains (MD)

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. Y.1731 uses MEG-IDs which are MAIDs without an MD name. User interfaces show the pseudo MD name, but this name is not included in Y.1731 CCM's MEGID. It is not possible to delete pseudo MDs.

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 add a new Maintenance Domain or click the name of an existing Maintenance Domain to edit its settings.

3. Complete the required fields, then click Apply.

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

Maintenance Domain (SOAM ▶CFM ▶MD)

Deleting a Maintenance Domain (MD)

To delete a maintenance domain

1. Access the page SOAM ▶CFM ▶MD.

2. Click the name of the MD instance to delete.

3. Click Delete.

Setting Up Maintenance Associations (Maintenance Entity Groups)

Before setting up a Maintenance Association or 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 are discussed in IEEE 802.1ag. Maintenance Entity Groups are discussed in ITU-T Y.1731.

The remote MEP auto-discovery feature is intended to make it easier to configure MA/MEGs because it eliminates the process of manually building the comma-separated list of up to 255 associated MEPs (i.e. the MEPID list). With the remote MEP auto-discovery, Connectivity Check Messages (CCM) are processed as they are received by the MEP and the associated remote MEP is automatically added to the MEPID list. An R-CCM alarm is raised in the SOAM▶CFM ▶MEP ▶Status page when CCMs are no longer being received by a MEP; this MEP will be monitored until its MEPID is manually removed from the MEP IP list.

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 edit its settings.

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)

To delete a Maintenance Association (Maintenance Entity Group)

1. Access the page SOAM ▶CFM ▶MA/MEG.

2. Click the name of the Maintenance Association or Maintenance Entity Group name to delete.

3. Click Delete.

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 existing 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 edit its settings.

3. Complete the required fields, then click Apply to start the CCM.

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

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

EVC Client Interface (The EVC client is the client of a service.)

To delete a Maintenance association End Point

1. Access the page SOAM ▶CFM ▶MEP.

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 index value, MEPID, database, or by any of the provided status codes.
   

   ---

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

   ---

3. Click any MEPID to view detailed status of this MEP.

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

MEP Status (SOAM ▶CFM ▶MEP ▶Status

Defects (Alarm Conditions)

Loopback (The status of the latest loopback request initiated from that MEP)

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])

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)