Static or Dynamic Demux Subscriber Interfaces over Aggregated Ethernet Overview

Options for Aggregated Ethernet Logical Interfaces That Support Demux Subscriber Interfaces

Traffic forwarding through a demux logical interface is dependent on the configuration of the underlying interface. Using an aggregated Ethernet interface as the underlying interface for a static or dynamic demux subscriber interface provides you with the following options:

• 1:1 Active/Backup Link Redundancy—If you need to support one-to-one active/backup link redundancy, configure the aggregated Ethernet interface in link protection mode, which requires that two underlying physical interfaces be designated as primary and backup links. In addition, if you need to support one-to-one active/backup link redundancy at the line card level, configure the aggregated Ethernet interface on physical interfaces that reside either on different EQ DPCs or on different MPCs. When using LACP link protection, you can configure only two member links to an aggregated Ethernet interface: one active and one standby.

• Load Balancing—You can configure load balancing instead of 1:1 active/backup link redundancy. The Junos OS implementation of the IEEE 802.3ad standard balances traffic across the member links within an aggregated Ethernet bundle based on the Layer 3 information carried in the packet.

  By default, the system supports hash-based distribution in load balancing scenarios. In this model, traffic for a logical interface can be distributed over multiple links in the aggregated Ethernet interface. If distribution flows are not even, egress CoS scheduling can be inaccurate. In addition, scheduler resources are required on every link of the aggregated Ethernet interface.

  Targeted distribution enables you to target the egress traffic for IP and VLAN demux subscribers on a single member link, using a single scheduler resource. The system distributes the subscriber interfaces equally among the member links.

Hardware Requirements with Static or Dynamic Demux Subscriber Interfaces over Aggregated Ethernet

IP demux subscriber interfaces over aggregated Ethernet interfaces are supported on EQ DPCs.

VLAN demux subscriber interfaces over aggregated Ethernet interfaces are supported on MX Series routers that only have MPCs installed. If the router has other line cards in addition to MPCs, the CLI accepts the configuration but errors are reported when the subscriber interfaces are brought up.

Features Supported with Static or Dynamic Demux Subscriber Interfaces over Aggregated Ethernet

Table 1 lists key subscriber access features supported with static or dynamic demux subscriber interfaces, organized by type of underlying interface:

• Aggregated Ethernet

• Non-aggregated Ethernet (Gigabit Ethernet, Fast Ethernet, or 10-Gigabit Ethernet)

There are no feature limitations specific to demultiplexing. Instead, demux interfaces over aggregated Ethernet are subject to the same scaling and configuration limitations inherent to aggregated Ethernet logical interfaces.