User guide

RUGGEDCOM ROS
User Guide
Chapter 5
Setup and Configuration
Configuring Classes of Service Globally 153
After inspection, the frame is forwarded to the egress port for transmission.
2. Forwarding Phase
Once the CoS of the frame is determined, the frame is forwarded to the egress port, where it is collected into
one of the priority queues according to the assigned CoS.
CoS weighting selects the degree of preferential treatment that is attached to different priority queues. The
ratio of the number of higher CoS to lower CoS frames transmitted can be configured. If desired, lower CoS
frames can be transmitted only after all higher CoS frames have been serviced.
Upon transmission, a new priority level can also be assigned to a frame based on its assigned CoS if it was
originally received untagged. For more information about mapping priority levels to outbound frames, refer to
Section 5.4.4, “Configuring CoS to Priority Mapping”.
The following sections describe how to configure and manage Classes of Service:
• Section 5.4.1, “Configuring Classes of Service Globally”
• Section 5.4.2, “Configuring Classes of Service for Specific Ethernet Ports”
• Section 5.4.3, “Configuring Priority to CoS Mapping”
• Section 5.4.4, “Configuring CoS to Priority Mapping”
• Section 5.4.5, “Configuring DSCP to CoS Mapping”
Section 5.4.1
Configuring Classes of Service Globally
To configure global settings for Classes of Service (CoS), do the following:
1. Navigate to Classes of Service » Configure Global CoS Parameters. The Global CoS Parameters form
appears.
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2
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Figure 101: Global CoS Parameters Form
1. CoS Weighting List 2. Apply Button 3. Reload Button
2. Configure the following parameter(s) as required:
Parameter Description
CoS Weighting Synopsis: { 1:1, 2:1, 4:1, 6:1, 8:1, 10:1, 12:1, 1:0 }
Default: 2:1
During traffic bursts, frames queued in the switch pending transmission on a port
may have different CoS priorities. This parameter specifies weighting algorithm for
transmitting different priority CoS frames.
Examples:
• 1:1 - 1 Critical priority CoS frame and 1 Normal priority CoS frame