Configuring Policy Class Of Service (Cos) - Enterasys N Standalone (NSA) Series Configuration Manual

Policy Classification Configuration Command Set

Configuring Policy Class of Service (CoS)

8.3.3 Configuring Policy Class of Service (CoS)
Using Port-Based or Policy-Based CoS Settings
NOTE: It is recommended that you use Enterasys Networks NetSight Atlas Policy
Manager as an alternative to CLI for configuring policy-based CoS on the Matrix Series
devices.
The Matrix Series device supports Class of Service (CoS), which allows you to assign
mission-critical data to higher priority through the device by delaying less critical traffic during
periods of congestion. The higher priority traffic through the device is serviced first before lower
priority traffic. The Class of Service capability of the device is implemented by a priority queueing
mechanism. Class of Service is based on the IEEE 802.1D (802.1p) standard specification, and
allows you to define eight priorities (0-7, with 7 granted highest priority) and, depending on port
type, up to 16 transmit queues (0-15) of traffic for each port.
Enterasys Networks' enhanced CoS implementation allows you to use the following methods to
configure Class of Service on the Matrix Series device:
•
Allowing the device to automatically assign policy-based inbound rate limiters and transmit
queues as described in this section.
•
Configuring transmit queueing and rate limiting on a per-port basis as described in
By defult, policy-based CoS is disabled on the device, and default or user-assigned port-based
802.1D (802.1p) settings are used to determine transmit queues and traffic rate limiting. When
policy-based CoS is enabled, the default and user-assigned settings will override port-based settings
described in Chapter
About Policy-Based CoS Default and User-Defined Configurations
Once enabled using the set cos state command as described in
CoS function provides the following default configuration:
•
Transmit queues (TXQ)-- A strict-priority queueing mechanism which gives higher priority
queues absolute preferential treatment over low priority queues. This ensures the transmit port
does not serve a transmit queue unless all higher priority queues are empty. As described
previously in this section, eight priority designations and transmit queues are defined for each
port.
•
Inbound rate limiting (IRL) -- No inbound rate limiters are configured.
8-44 Matrix NSA Series Configuration Guide
9.
Section 8.3.3.2, the policy-based
Chapter 9.