Tyco 0-1591099-x Priority Configuration, Modify the Egress Mapping, Modify the Egress Weighting

24 Port Stackable Managed Switch – User Guide Page 29

Priority Configuration

The Switch supports basic QoS operation with the ability to map the 0-7 priority levels in IEEE802.1p to either the low or high priority egress queue buffers. In addition the relative weighting of high to low packets egressing from the Switch can also be programmed. This menu section is selected from the Switch Configuration menu screen.

Figure 28. Priority Configuration Screen

Modify the Egress Mapping

After the Priority Configuration menu has been selected, the priority screen is displayed and this enables the control of the QoS egress mapping. To adjust the mapping, select <edit> from the action line and the cursor moves to the first map level. Use the <spacebar> key to toggle between <low> and <high> settings. The default mapping is Levels 0-3 are Low priority and Levels 4-7 are High priority.

Modify the Egress Weighting

The Switch can be programmed to control the relative flow of high and low priority packets from the egress port. Note that this weighting algorithm is applied to the whole Switch and not specific ports. To adjust the weighting algorithm, select <edit> from the action line and the cursor moves to the first map level. Use the <tab> key to move through the mapping options to the QoS Mode field. Then select the required algorithm using the <spacebar>. The weighting options are:

All High Before Low – All high priority packets are sent before low priority (default)

Weight Round Ratio x:1 – The Switch will send x high priority packets followed by a low priority packet (x can be between 2 to 7)

First Come First Serve – The first packet to arrive is sent out first (no actual priority is applied).

Use the <esc> key to return to the action line and ensure that the settings are saved by selecting the <apply> field.

Product Number 0-1591099-x © Tyco Electronics 2005 Issue 1