Overview

The Easy ECN feature streamlines the traditionally complex configuration of Explicit Congestion Notification (ECN) by eliminating the need for manual setup of interface queues, WRED (Weighted Random Early Detection) policies, thresholds, and drop probabilities. In standard ECN configurations, users need to configure multiple parameters, such as:

• Enabling ECN on specific interface queues, ensuring that the network is aware of which traffic classes should use ECN.

• Setting WRED thresholds, which determine at what point packets will be marked or dropped based on queue depth.

• Configuring the maximum packet drop probability, dictating how likely a packet is to be dropped when congestion is high.

Easy ECN simplifies all of these by allowing users to configure ECN with just a single command, focusing on the network’s traffic optimization strategy.

By using the command set class-of-service easy-ecn mode <throughput-first | latency-first>, network administrators can efficiently configure ECN with a focus on either throughput or latency globally for all the interface queues, without needing to manually set all the individual parameters for each interface queue. This simplified approach not only saves time but also ensures more consistent and effective congestion management.

1. Throughput-first Mode: This mode prioritizes maximizing the amount of data transferred across the network, making it ideal for use cases such as bulk data transfers or content delivery systems. It dynamically adjusts traffic flow to ensure that congestion management does not overly restrict throughput, while still using ECN to prevent excessive congestion.

2. Latency-first Mode: This mode prioritizes minimizing latency, ensuring that packets experience the least possible delay. This is particularly important for real-time applications such as VoIP, video conferencing, or online gaming, where even small delays can negatively impact performance.

Table 1 below shows ECN threshold and marking probability values for throughput-first and latency-first modes on Tomahawk3 and Trident3 platforms.

Table 1. ECN Threshold and Marking Probability: Throughput-First vs. Latency-First

To simplify the configuration, users can enable Easy ECN for global congestion management. However, if the global configuration does not fully address the specific needs of queue-level congestion management, standard ECN can be fine-tuned for individual interface queues.

Configuration Notes and Constraints

When configuring Easy ECN, consider the following points:

• Easy ECN is only supported on Trident3-X5, Trident3-X7 and Tomahawk3 platforms.

• Throughput-First mode prioritizes high data transfer rates. It is ideal for environments where bulk data transmission is critical. Latency-First mode focuses on minimizing delays in packet transmission, making it suitable for real-time applications (e.g., VoIP, video streaming).

• Easy ECN provides a simplified, global configuration for congestion management. If more granular control is required, standard ECN can be configured on specific interface queues. In such cases, interface-specific ECN configurations override global settings.

Configuring Easy ECN

To simplify the configuration, users can enable Easy ECN for global congestion management. However, if the global configuration does not fully address the specific needs of queue-level congestion management, standard ECN can be fine-tuned for individual interface queues.

The following command can be used to enable easy ECN globally.

set class-of-service easy-ecn mode <throughput-first | latency-first>

Example

• Configure easy ECN mode to latency-first.      

• Configure easy ECN mode to throughput-first.