Queue Statistics on Sx500 Series Stackable Switches

Objective

Queue management is used in Quality of Service (QoS) internetwork architecture. Queuing is a technique used in network devices like routers and switches to handle congestion. Packets are held in queues for processing. After processing they are sent to the destination. Queue statistics give the information about the number of packets forwarded and number of packets dropped depending upon the interface, queue and drop precedence.

The objective of this article is to guide you on how to add queue statistics for a particular interface on the Sx500 Series Stackable Switches.

Applicable Devices

• Sx500 Series Stackable Switches

Software Version

• 1.3.0.62

Add Queues Statistics

Step 1. Log in to the web configuration utility and choose Quality of Service > QoS Statistics > Queues Statistics. The Queues Statistics page opens:

The Queue Statistics page displays the following information:

• Counter Set — Queue statistics for a particular counter set.

• Interface — Queue statistics for a particular interface.

• Queue — Packets are either forwarded or dropped from this queue.

• Drop Precedence — Queue statistics for a particular drop precedence value. More is the drop precedence value implies high probability of packets being dropped during congestion.

• Total Packets — The total number of packets forwarded or dropped.

• Tail Drop Packets — The percentage of packets that are dropped.

Step 2. (Optional) If you want to refresh the queue statistics periodically, choose the refresh time and then select the appropriate radio button. Select No Refresh radio button if you don't want to refresh the queue statistics.

Step 3. Click Add. The Add Queues Statistics window appears:

 Step 4. Choose the particular counter set value from the Select Counter Set drop-down list.

• Set 1 — This set contains all the interfaces and queues with high Drop Precedence.

• Set 2 —This set contains all the interfaces and queues with low Drop Precedence.

Step 5. Choose the interface port for which you want to add queues statistics. The possible options are:

• Unit No. — From the Unit/Slot drop-down list choose a particular value. It specifies the unit in stack.

• Port — From the Port drop-down list choose a port for which you want to add queue statistics.

• All Ports — Click the All Ports radio button if you want to add queue statics on all the ports.

Step 6. Choose a particular queue from the Queue field for which you want to add the statistics and click the corresponding radio button. Click All radio button if you want add statistics on all the queues. The range of queue values is 1 - 4.

Step 7. Choose a particular drop precedence value from the Drop Precedence field and click the corresponding radio button. Drop precedence helps decide which packets have to be discarded during congestion. Packets with higher drop precedence are dropped earlier than the packets with low drop precedence value.

Step 8. Click Apply. The desired queue statistics are added. Click Close to return to the Queue Statistics page.