qos burst-mode (system view)
Function
The qos burst-mode command configures a burst traffic buffer mode on a switch.
The undo qos burst-mode command restores the default burst traffic buffer mode on a switch.
By default, the switch uses the standard mode.
Only the S5720-EI, S5732-H, S6720-EI, S6720-HI, S6720S-EI, S6730-H, S6730S-H, S6730-S, and S6730S-S support this command.
Format
qos burst-mode { enhanced | extreme } slot slot-id
undo qos burst-mode { enhanced | extreme } slot slot-id
Parameters
Parameter |
Description |
Value |
|---|---|---|
| enhanced | Indicates the enhanced burst traffic buffer mode. |
- |
| extreme | Indicates the extreme burst traffic buffer mode. |
- |
| slot slot-id | The default value of slot-id is 0 on a non-stacked switch. slot-id specifies the stack ID. |
- |
Usage Guidelines
Scenario
By default, the buffer size on an interface is small. When the traffic rate on an interface reaches 50% to 60% of the interface bandwidth, packet loss occurs on the interface. After the burst traffic buffer mode is configured on a switch, all interfaces on the switch can occupy more buffer space in the system to process burst traffic, improving a switch's packet processing performance.
The device buffer is allocated in static and dynamic modes. By default, each interface is allocated some static buffer space for the basic buffer requirement. The remaining buffer space is used as the dynamic buffer for a switch.
In standard mode, an interface can occupy only some dynamic buffer space on the switch.
In enhanced mode, an interface can occupy only some dynamic buffer space on the switch, and more dynamic buffer space than that in standard mode.
In extreme mode, an interface occupies the dynamic buffer space as well as static buffer space on interfaces in non-extreme mode.
Precautions
The qos burst-mode (system view) and qos queue buffer shared-ratio commands cannot be used on the switch simultaneously.
The extreme mode is not recommended because forwarding of other interfaces may be affected and QoS results such as scheduling and shaping results may be incorrect.
The extreme mode is used only when the switch uses one or two interfaces. This mode takes effect only when it is configured globally and on an interface. If the extreme mode is configured globally but is not configured on an interface, traffic forwarding may be abnormal and multicast packets may fail to be obtained. If the extreme mode is configured on an interface but is not configured globally, the extreme mode does not take effect.
When the extreme mode is configured globally, the interface where the extreme mode is not configured cannot be used as a service interface.