Primary VLAN support for Ethernet CFM

Primary VLAN feature description

A VLAN assigned for service monitoring is considered the Primary VLAN. By setting a Primary VLAN identifier, you can perform additional ETH-CFM extraction checking.

By default, the ETH-CFM processing uses a SAP or SDP binding configuration to determine the proper offset for the start of the ETH-CFM e-type 0x8902 PDU. Any packet that includes ETH-CFM (e-type 0x8902) at the appropriate offset will be subjected to the extraction routines for MEPs or MIPs provided the Primary VLAN is enabled. If the ETH-CFM is not at the appropriate offset, the packets pass as user data. When a MEP is configured without a Primary VLAN, only the classic extraction is performed.

The default mapping of the ingress packet is based on the Layer 2 mapping which in turn, is mapped to the appropriate MEP. If the mapping does not match, as in the case of ambiguous or additional VLAN tags beyond the SAP or SDP binding delineation, then additional lookups for ETH-CFM are possible.

This is applicable where a single VLAN or aggregate is transporting many VLANs underneath that aggregate function. It is also applicable to dot1q networks that carry multiple tags without using the default SAP. Fully-qualified SAPs/SDP binding are also able to use the Primary VLAN function. The extraction function is the same for either fully-qualified or ambiguous SAPs/SDP binding.

A MEP or MIP must be configured on a particular SAP or SDP binding to perform any ETH-CFM extraction. The classic extraction (which is the matching of the ETH-CFM packets immediately following the SAP/SDP binding configuration) is performed first. If the Ethernet encapsulation is set to dot1q and the SAP configuration is x/y/z:*, then the ETH-CFM extraction looks for ETH-CFM to appear in the header with no VLAN tags preceding it. If there is a match on this classic extraction, then no further extraction routines are invoked. If the classic extraction fails and a second MEP is configured with Primary VLAN enabled, then the additional extraction will check to see if ETH-CFM immediately follows the specified Primary VLAN. If that is true, then the VLAN will be used as an index into the primary VLAN table and the extraction is performed based on normal criteria following the ETH-CFM rules.

The Primary VLAN function is supported for up and down MEPs, as well as ingress and egress MIPs on an Ethernet SAP for VPLS and Epipe service MEPs (including Local Switched PBB ePipe with PBB Tunnel backup). Primary VLAN support is only applicable to service MEPs and not facility MEPs (specifically, not tunnel MEPs). Facility MEPs are meant to validate the transport and not the switching capability of a network element.

Primary VLAN support for 7210 SAS NEs varies depending on chassis type, release version, and card type. See the NE documentation for more information.

When enabling this function, an operator can specify the VLAN ID for generated MEG sites, and also whether or not the MEP should be a Primary VLAN MEP or MIP (only applicable to SAP/SDP binding MEPs or MIPs on VPLS and Epipe services).

The CCM test execution routine checks if all MEPs in the MEG or MEG Sub-group match before allowing the test execution to proceed.

Points to consider when enabling the Primary VLAN function:

• A unique MA should be employed for each Primary VLAN.

• The Primary VLAN function is only applied to SAPs and spoke and mesh SDP bindings. Virtual MEPs are not supported.

• The MHF-Creation parameter must be set to the static option to force the generation of Primary VLAN MIPs.

• Primary VLAN MEPs can only be assigned at creation time.

• Primary VLAN MEPs must have an MA Service VLAN ID correctly set.

• The MA Service VLAN ID cannot be changed if Primary VLAN MEPs exist.

• Multiple Primary VLAN MEPs per SAP or SDP bindings are supported. There is no restriction on the number of MEPs that are allowed on SAPs/SDP binding for this feature. Both the classic extraction context and every Primary VLAN on the SAPs/SDP binding can support up to 16 MEPs (8 Up and 8 Down), one per MD level.

• All eight MD levels can be configured on all MEPs (0-7) that are configured on a SAP/SDP binding, within their specific context (classic or Primary VLAN). This allows an operator to have the complete range of eight MD levels for use in the specified Primary VLAN. This avoids conflicts when the same MD Level and Layer 2 encapsulation maps to two different MEPs in the different contexts.

• Levels are specific within each of the contexts (classic and all the Primary VLANs configured on the same SAP/SDP binding). Therefore each lookup can have overlapping levels. The hierarchy is maintained within the extraction context.

• Primary VLAN MEPs and Fault Propagation are mutually exclusive.

• Primary VLAN MEPs and Fast CCM Interval are mutually exclusive.

• There is no sub-second CCM support for Primary VLAN enabled MEPs.