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Configuring BA Classifiers for Bridged Ethernet

On M120 and M320 routers equipped with IQ2 PICs, you can configure BA classification based on the IEEE 802.1 bits for bridged Ethernet over Asynchronous Transfer Mode (ATM), Point-to-Point Protocol (PPP), and frame relay for VPLS applications. The BA classification is applied to the first (outer) tag when tagged frames are received. Untagged frames are bypassed and a value of 000 for the classification IEEE 802.1p bits is assumed. There is no support for circuit cross-connect (CCC), and only port-mode VPLS is supported (in port-mode VPLS, only VLANs on a single physical port are included in the VPLS instance). There is no support for multilink PPP bonding with VPLS. For bridging over frame relay, only frames that do not preserve the frame check sequence (FCS) field are supported. Frames that preserve the FCS field are silently discarded.

The bridging over PPP function is restricted:

  • There is no support for “tinygram” compression and expansion.

  • Frames received with preserved FCS bits are silently discarded.

  • Bridge control frames are also classified based on header bit values.

  • Both tagged and untagged frames are classified and forwarded. The peer must discard frame types that are not supported.

The following example applies an IEEE 802.1p classifier named ppp-ether-vpls-classifier to interface (so-1/2/3) with Ethernet VPLS over PPP encapsulation.


The interface and CoS configuration must be consistent to support the feature. You must also configure the classifier and other CoS parameters such as forwarding classes.

  1. Apply the CoS behavior aggregate classifier to a logical interface.
  2. Configure the encapsulation and protocol family for the interface.
  3. Verify the configuration.
  4. Save the configuration.

On routers with IQ2 or IQ2E PICs, you can perform BA classification based on the value of the inner VLAN tag in an Ethernet frame.

  1. To configure BA classification based on the inner VLAN tag value, speciy the inner option at the [edit class-of-service interfaces interface-name unit logical-unit-number classifiers ieee-802.1 classifier-name vlan-tag] hierarchy level. You must also configure the inner VLAN tag for the logical interface with the inner option at the [edit interfaces interface-name unit logical-interface-name vlan-tag] hierarchy level.

  2. Verify the configuration.

  3. Save the configuration.