Web Agent Procedure

To manage buffers and queues using the Web Agent:

1. Select Configuration from the Modules & Ports group on the Web Agent window. The Module Information dialog box opens (Figure 24-1).

Figure 24-1. Module Information Dialog Box

2. Select the module whose buffers you want to manage from the Select column.
3. Select the Module number for that module from the Buffer Management column. The Buffer Management dialog box opens (Figure 24-2).

Figure 24-2. Buffer Management Dialog Box

4. See Table 24-1 for an explanation of the Buffer Management dialog box parameters.

   Table 24-1. Buffer Management Dialog Box Parameters

   Parameter	Definition
   Fabric Port Buffers	Displays the port’s fabric port buffers and allows you to open the Buffer Detail Configuration dialog box for the selected module. Service ratios: 3 to 1 99 to 1 999 to 1 9999 to 1
   Physical Port Buffers	Displays the port’s physical port buffers if available. The buffer ratios are: 31 to 1 63 to 1 127 to 1 255 to 1 511 to 1 1023 to 1 2047 to 1 4095 to 1 8191 to 1 16383 to 1 32767 to 1

5. Select the Fabric Port Buffer number whose associated buffers you want to manage. The Buffer Detail Configuration dialog box for that fabric port opens (Figure 24-3).

Figure 24-3. Buffer Detail Configuration Dialog Box

6. See Table 24-2 for an explanation of the Buffer Detail Configuration dialog box input and output fields:

   Table 24-2. Buffer Detail Configuration Dialog Box Parameters 

   Parameter	Definition...
   Memory	Displays the amount of physical memory associated with this buffer.
   Age Timer	Displays the amount of time a packet remains in the queue before being discarded as a stale packet. You may want to increase the timer value for ports connected to 10 MB/s ports, particularly 10 MB/s shared media, because you may want to queue packets longer before discarding them.
   High Priority Allocation	Displays the percent of the buffer’s queuing space allotted to high priority traffic. Because the high-priority queue is serviced more frequently than the normal priority queue, raising this value may not necessarily provide better service. In fact, if you are using the high-priority queue for delay-sensitive traffic, you may want to reduce the amount of memory devoted to the high-priority queue. This ensures that packets that cannot be delivered in a timely manner are discarded. If you want the high priority queue to guarantee delivery of as many packets as possible, regardless of delay, increase this value. The change does not take effect until you reset the switch.
   Priority Threshold	Allows you to set this parameter to the value at which the switch starts sending packets to the high-priority queue. The default value (4) causes all traffic with a priority greater than or equal to 4 (4, 5, 6, and 7) to be assigned to the high-priority queue. Priority schemes have more than two queues (the IEEE allows up to 8, numbered 0 through 7). Avaya recommends that you do not change this parameter.
   High Priority Service Ratio	Allows you to set how many times the high priority queue is serviced for each time the low priority queue is serviced. The ideal value changes from queue to queue, but the goal is to ensure that traffic mix guarantees optimal mix between high-priority and best effort traffic.
   High and Normal Overflow Drops	Displays the number of packets dropped because the associated buffer is full. Indicates that the device immediately before the queue is processing traffic faster than the next downstream element can process the same volume of traffic. For example, overflow drops on the input buffer indicate that traffic is arriving faster than the switch matrix can process it. Overflow drops on the output buffers indicates that the output port cannot handle the volume of the load being offered.
   High and Normal Stale Drops	Displays the number of packets dropped because they timed out waiting for service (using the age timer value). In the high-priority queue, this can help determine how efficiently the switch is processing “better never than late” traffic. Excessive stale drops on the high-priority queue may indicate the need to increase the service ratio on the high-priority queue.
   Congestion Drops	Displays the number of packets dropped because the switch controller has sensed congestion at the outbound port.

7. Repeat Steps 1-4 to tune Physical Port (Fast Ethernet) buffers. Physical Port ports have additional buffers on both the input and output ports.
8. Click APPLY to save your changes, or CANCEL to restore previous settings.