(Optional) Configuring the Data Buffer

Context

The data buffer caches packets to be sent from an interface to prevent packet loss upon traffic bursts. When the data buffer is full, the device does not cache packets and directly discards packets not entering the buffer. You can adjust the buffering capacity of interface queues to improve the forwarding performance.

Procedure

Configure the maximum ratio of the dynamic buffer occupied by a queue on an interface of the S5720-EI, S6720-EI, and S6720S-EI.
1. Run system-view
  The system view is displayed.
2. Run interface interface-type interface-number
  The interface view is displayed.
3. Run qos queue queue-index buffer shared-ratio ratio-value
  The maximum ratio of the dynamic buffer occupied by a queue on an interface is set.
The maximum ratio of the dynamic buffer occupied by a queue on an interface and a burst traffic buffering mode of the interface or switch cannot be configured simultaneously.
Configure a burst traffic buffering mode on an interface of the S5720-EI, S5732-H, S6720-EI, S6720-HI, S6720S-EI, S6730-H, S6730S-H, S6730-S, and S6730S-S.
1. Run system-view
  The system view is displayed.
2. Run interface interface-type interface-number
  The interface view is displayed.
3. Run qos burst-mode { enhanced | extreme }
  A burst traffic buffering mode is configured on the interface.
  
  The enhanced mode is recommended because the extreme mode may affect forwarding on other interfaces.
A burst traffic buffering mode and the maximum ratio of the dynamic buffer occupied by a queue cannot be configured on the same interface simultaneously.
Configure a burst traffic buffering mode of the S5720-EI, S5732-H, S6720-EI, S6720-HI, S6720S-EI, S6730-H, S6730S-H, S6730-S, and S6730S-S.
1. Run system-view
  The system view is displayed.
2. Run qos burst-mode { enhanced | extreme } slot slot-id
  A burst traffic buffering mode is configured on the device.
  
  The enhanced mode is recommended because the extreme mode may affect forwarding on other interfaces.
A burst traffic buffering mode on a switch and the maximum ratio of the dynamic buffer occupied by a queue on an interface cannot be configured simultaneously.
Configure queue lengths on an interface of the S2720-EI, S5720-LI, S5720S-LI, S5720-SI, S5720S-SI, S5720I-SI, S5730-SI, S5730S-EI, S6720-LI, S6720S-LI, S6720-SI, and S6720S-SI.
1. Run system-view
  The system view is displayed.
2. Run qos tail-drop-profile profile-name
  A tail drop profile is created and its view is displayed.
3. Run the following commands as required.
  - Run qos queue queue-index max-length packet-number [ green max-length packet-number ]
    
    The length of a queue is set.
  - Run qos queue queue-index green max-length packet-number
    
    The length of a queue is set.
4. Run quit
  Return to the system view.
5. Run interface interface-type interface-number
  The interface view is displayed.
6. Run shutdown
  The interface is shut down.
7. Run qos tail-drop-profile profile-name
  The tail drop profile is applied to the interface.
8. Run undo shutdown
  The interface is started.
Configure the dynamic queue buffer adjustment function on the S5735-L, S5735S-L, S5735S-L-M, S5735-S, S5735-S-I, and S5735S-S.
1. Run system-view
  The system view is displayed.
2. Run qos dynamic-buffer enable
  The dynamic queue buffer adjustment function is enabled.
3. (Optional) Run qos dynamic-buffer interval
  The interval for dynamically adjusting the queue buffer is configured.
4. (Optional) Run qos dynamic-buffer max-maximum
  The maximum buffer size of a queue for which dynamic buffer adjustment is enabled is configured.
The dynamic queue buffer adjustment function takes effect only when multicast entries exist.