CoS for Interface Sets of Subscribers Overview

Guidelines for Configuring Dynamic Interface Sets in a Subscriber Access Network

When configuring interface sets for subscriber access, keep the following guidelines in mind:

• You can configure interface sets of VLAN demux, PPPoE, or demux interfaces over aggregated Ethernet interfaces.

• An interface can only belong to one interface set. If you try to add the same interface to different interface sets, the commit operation fails.

• You configure the interface set and the traffic scheduling and shaping parameters in a dynamic profile. However, you must apply the traffic-control profile to the interface set in the static [edit class-of-service] hierarchy.

  Note:

  This rule applies to all interface sets except ACI sets.

• The $junos-interface-set-name predefined variable is available only for RADIUS Accept messages; change of authorization (CoA) requests are not supported.

• The $junos-aggregation-interface-set-name is the L2 interface-set representing a logical intermediate node (DPU-C or PON tree) in the access network.

• The $junos-phy-ifd-underlying-intf-set-name represents a default, topology-based interface-set (based on the physical interface name with a post-pend of “-underlying”) to conserve L2 CoS nodes.

• The $junos-svlan-interface-set-name predefined variable locally generates an interface set name for use by dual-tagged VLAN interfaces based on the outer tag of the dual-tagged VLAN. The format of the generated variable is physical_interface_name - outer_VLAN_tag. For example, an aggregated Ethernet interface “ae0,” with a dual-tagged VLAN interface that has an outer tag of “111,” results in a $junos-svlan-interface-set-name dynamic variable of “ae0-111”. Similarly, a non-aggregated Ethernet interface of ge-1/1/0, with the same dual-tagged VLAN interface that has an outer tag of “111,” results in a $junos-svlan-interface-set-name dynamic variable of “ge-1/1/0-111”.

• The $junos-phy-ifd-interface-set-name predefined variable locally generates an interface set name associated with the underlying physical interface in a dynamic profile. This predefined variable enables you to group all the subscribers on a specific physical interface so that you can apply services to the entire group of subscribers.

  Another use case for this predefined variable is to conserve CoS resources in a mixed business and residential topology by collecting the residential subscribers into an interface set associated with the physical interface, so that a level 2 node is used for the interface set rather than for each residential interface. Otherwise, because the business and residential subscribers share the same interface and business subscribers require three levels of CoS, then three levels are configured for each residential subscriber. That results in an unnecessary level 2 node being consumed for each residential connection, wasting CoS resources.

• The $junos-tagged-vlan-interface-set-name predefined variable locally generates an interface set name used for grouping logical interfaces stacked over logical stacked VLAN demux interfaces for either a 1:1 (dual-tagged; individual client) VLAN or N:1 (single tagged; service) VLAN. The format of the generated variable differs with VLAN type as follows:

  • Dual-tagged (client) VLAN—physical_interface_name - outer_VLAN_tag - inner_VLAN_tag. For example, an aggregated Ethernet interface “ae0,” with a dual-tagged VLAN interface that has an outer tag of “111” and an inner tag of “200,” results in a $junos-tagged-vlan-interface-set-name dynamic variable of “ae0-200-111”. Similarly, a non-aggregated Ethernet interface of ge-1/1/0, with the same dual-tagged VLAN interface that has an outer tag of “111” and an inner tag of “200,” results in a $junos-tagged-vlan-interface-set-name dynamic variable of “ge-1/1/0-200-111”.

  • Single tagged (service) VLAN—physical_interface_name - VLAN_tag. For example, an aggregated Ethernet interface “ae0,” with an N:1 VLAN using the single tag of “200,” results in a $junos-tagged-vlan-interface-set-name dynamic variable of “ae0-200”. Similarly, a non-aggregated Ethernet interface of ge-1/1/0, with the same N:1 VLAN using the single tag of “200,” results in a $junos-tagged-vlan-interface-set-name dynamic variable of “ge-1/1/0-200”.

• All dynamic demux, dual-tagged VLAN logical interfaces with the same outer VLAN tag and physical interface are assigned to the same interface set and all CoS values provisioned with the dynamic profile are applied to the interfaces that are part of the set.

• The interface set name must be explicitly referenced in the CoS configuration as part of the static configuration outside of the dynamic profile. The CoS configuration is static and the interface set name must be statically referenced.

  Note:

  This rule applies to all interface sets except ACI sets.

• RADIUS can return an access-accept message under certain conditions. A configured RADIUS VSA for the interface set name takes precedence over the locally generated variable on the router. This means that if the interface-set-name VSA is configured on RADIUS, the router continues to use this variable instead of the locally generated value from the dynamic variable.

• Sets of aggregated Ethernet interfaces are supported on MPC/MIC interfaces on MX Series routers only.

• The supported interface stacks for aggregated Ethernet in an interface set include VLAN demux interfaces, IP demux interfaces, and PPPoE logical interfaces over VLAN demux interfaces.

• The link membership list and scheduler mode of the interface set are inherited from the underlying aggregated Ethernet interface over which the interface set is configured.

• When an aggregated Ethernet interface operates in link protection mode, or if the scheduler mode is configured to replicate member links, the scheduling parameters of the interface set are copied to each of the member links.

• If the scheduler mode of the aggregated Ethernet interface is set to scale member links, the scheduling parameters are scaled based on the number of active member links and applied to each of the aggregated interface member links.