Dell PowerConnect 5548 User Guide - Page 659

QoS Basic Mode This section describes QoS Basic mode. It contains the following topics: • Basic Mode Overview • Workflow to Configure Basic Mode • Global Settings • DSCP Rewrite • Interface Settings Basic Mode Overview In QoS Basic mode, a specific domain in the network can be defined as trusted. Within that domain, packets are marked with CoS priority and/or DSCP values, to signal the type of service they require. Nodes within the domain use these fields to assign the packet to a specific output queue. The initial packet classification and marking of these fields is done in the ingress of the trusted domain. Workflow to Configure Basic Mode To configure Basic QoS mode, perform the following: 1 Select Basic mode for the system in the QoS Mode page. 2 Select the trust-behavior in the Global Settings page. 3 If there is any port that, as an exception, should not trust the incoming CoS mark, disable the QoS state on that port in the Interface Settings pages. If a port is disabled without trusted mode, all its ingress packets are forwarded in best effort. It is recommended that you disable the trusted mode at the ports where the CoS and/or DSCP values in the incoming packets are not trustworthy. Otherwise, performance in the network might be negatively affected. 4 If you selected DSCP Rewrite in the Global Settings page, set the DSCP in/out values in the DSCP Rewrite page. Dell PowerConnect 55xx Systems User Guide 659