Creating an E-LAN Service Order with CFM

Ethernet interfaces support the IEEE 802.1ag standard for Operation, Administration, and Management (OAM). The IEEE 802.1ag specification provides for Ethernet connectivity fault management (CFM). CFM monitors Ethernet networks that might comprise one or more service instances for network-compromising connectivity faults.

The major features of CFM are:

Fault monitoring using the continuity check protocol. This is a neighbor discovery and health check protocol that discovers and maintains adjacencies at the VLAN or link level.
Path discovery and fault verification using the linktrace protocol. Similar to IP traceroute, this protocol maps the path taken to a destination MAC address through one or more bridged networks between the source and destination.
Fault isolation using the loopback protocol. Similar to IP ping, this protocol works with the continuity check protocol during troubleshooting.

CFM partitions the service network into various administrative domains. For example, operators, providers, and customers might be part of different administrative domains.

Each administrative domain is mapped into one maintenance domain providing enough information to perform its own management, thus avoiding security breaches and making end-to-end monitoring possible. Each maintenance domain is associated with a maintenance domain level from 0 through 7. Level allocation is based on the network hierarchy, where outermost domains are assigned a higher level than the innermost domains.

Customer end points have the highest maintenance domain level. In a CFM maintenance domain, each service instance is called a maintenance association. A maintenance association can be thought as a full mesh of maintenance endpoints (MEPs) having similar characteristics. MEPs are active CFM entities generating and responding to CFM protocol messages.

There is also a maintenance intermediate point (MIP), which is a CFM entity similar to the MEP, but more passive (MIPs only respond to CFM messages).

MEPs can be up MEPs or down MEPs. A link can connect a MEP at level 5 to a MEP at level 7. The interface at level 5 is an up MEP (because the other end of the link is at MEP level 7), and the interface at level 7 is a down MEP (because the other end of the link is at MEP level 5).

In a Metro Ethernet network, CFM is commonly used at two levels:

By the service provider to check the connectivity among its provider edge (PE) routers
By the customer to check the connectivity among its customer edge (CE) routers

Note:
The configured customer CFM level must be greater than service provider CFM level.

In many Metro Ethernet networks, CFM is used to monitor connectivity over a VPLS and bridge network.

The CFM profile is propagated to a single endpoint when multiple interfaces are selected for a given device (the last interface overrides the other configurations). When you enable CFM for an interface of a particular device, you cannot enable CFM on other interfaces of the same device. The CFM configuration is pushed only on the selected interface. When you delete the interface with CFM enabled, the CFM configuration on the particular device is also removed. When you attempt to delete an interface with CFM enabled, you are prompted to confirm the deletion.

To create an E-LAN service order with CFM enabled:

Select Service View from the View Selector. The workspaces that are applicable to network and tunnel services are displayed.
From the Junos Space user interface, click the Deploy icon in the Connectivity Services Director banner. The functionalities that you can configure in this mode are displayed in the task pane.
From the View pane, click the plus sign (+) to expand the tree and select the type of service.
Click the plus sign (+) beside Connectivity to view services based on protocols.
- Expand the IP Services tree to select an IP service.
- Expand the E-Line Services tree to select an E-Line service.
- Expand the E-LAN Services tree to select an E-LAN service.
From the Tasks pane, select Service Provisioning > Deploy Services.
The Manage Network Services page is displayed in the top half of the right pane, which displays all of the configured services. The Manage Service Orders page is displayed in the bottom half of the right pane, which displays all of the service orders corresponding to a service.
From the Manage Network Services page, select New > E-LAN Service Order.
The Create E-LAN Service Order window appears and shows a filtered inventory view of only those published service orders designed to work with multipoint Ethernet services.

See Creating a Multipoint-to-Multipoint E-LAN Service Order and Creating a Point-to-Multipoint E-LAN Service Order for detailed information about the settings that you can configure on the Service Settings and Node Settings pages of the wizard.
After you complete the configuration of settings on the Service Settings and Node Settings pages of the service order creation or modification wizard, click Site Settings at the top of the wizard page.
The Site Settings page is displayed.
Select the Enable CFM check box beside a particular interface of a device in the service order creation and modification wizards to enable connectivity fault management (CFM) on the interface. Based on your network needs, you can create a point-to-multipoint and a multipoint-to- multipoint E-LAN service with service-level CFM enabled. The CFM profile is propagated to a single endpoint when multiple interfaces are selected for a given device (the last interface overrides the other configurations). When you select the Enable CFM check box for an interface of a particular device, you cannot enable CFM on other interfaces of the same device. The CFM configuration is pushed only on the selected interface.
When you delete the interface with CFM enabled, the CFM configuration on the particular device is also removed. When you attempt to delete an interface with CFM enabled, you are prompted to confirm the deletion.
For service orders associated with a service definition that contains a service template, click Next to modify the template settings.
Click Review to examine and modify the settings as necessary.
Click Finish when you have completed examining the settings to confirm the creation of the service order.

Creating an E-LAN Service Order with CFM

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