Cisco Systems ASA 5580 Manual De Usuario

To determine the priority queue and TX ring limits, use the worksheets below.

 shows how to calculate the priority queue size. Because queues are not of infinite size, they 

can fill and overflow. When a queue is full, any additional packets cannot get into the queue and are 
dropped (called tail drop). To avoid having the queue fill up, you can adjust the queue buffer size 
according to the 

 shows how to calculate the TX ring limit. This limit determines the maximum number of 

packets allowed into the Ethernet transmit driver before the driver pushes back to the queues on the 
interface to let them buffer packets until the congestion clears. This setting guarantees that the 
hardware-based transmit ring imposes a limited amount of extra latency for a high-priority packet.

__________

1.

For example, DSL might have an uplink speed of 768 Kbps. Check with your provider.

Mbps

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Kbps

__________

___________

 

__________

2.

Determine this value from a codec or sampling size. For example, for VoIP over VPN, you might use 160 bytes. We recommend 256 
bytes if you do not know what size to use.

__________

3.

The delay depends on your application. For example, the recommended maximum delay for VoIP is 200 ms. We recommend 500 ms 
if you do not know what delay to use.

__________

__________

1.

For example, DSL might have an uplink speed of 768 Kbps.Check with your provider.

Mbps

__________

Kbps

__________

___________

 

__________

__________

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