Edge-Core ECS4120-28F, Reference Manual, Page: 462 / 938

Chapter 15
| Congestion Control Commands
Automatic Traffic Control Commands
– 462 –
Usage Guidelines
ATC includes storm control for broadcast or multicast traffic. The control response
for either of these traffic types is the same, as shown in the following diagrams.
Figure 1: Storm Control by Limiting the Traffic Rate
The key elements of this diagram are described below:
◆
Alarm Fire Threshold – The highest acceptable traffic rate. When ingress traffic
exceeds the threshold, ATC sends a Storm Alarm Fire Trap and logs it.
◆
When traffic exceeds the alarm fire threshold and the apply timer expires, a
traffic control response is applied, and a Traffic Control Apply Trap is sent and
logged.
◆
Alarm Clear Threshold – The lower threshold beneath which a control response
can be automatically terminated after the release timer expires. When ingress
traffic falls below this threshold, ATC sends a Storm Alarm Clear Trap and logs it.
◆
When traffic falls below the alarm clear threshold after the release timer
expires, traffic control (for rate limiting) will be stopped and a Traffic Control
Release Trap sent and logged. Note that if the control action has shut down a
port, it can only be manually re-enabled using the
auto-traffic-control control-
release command).
◆
The traffic control response of rate limiting can be released automatically or
manually. The control response of shutting down a port can only be released
manually.
Storm Alarm
Fire TRAP
Alarm Fire
Threshold
（1～255kpps）
AlarmClear
Threshold
（1～255kpps）
Traffic
[kpps]
Time
Traffic without storm control
Traffic with storm control
Apply Timer
expired
(0～300sec)
Auto Storm Control
Release Timer
expired
(0～300sec)
Storm Alarm
Fire TRAP
StromAlarm
ClearTRAP
TrafficControl
Apply Trap
StromAlarm
ClearTRAP
TrafficControl
Release Trap
Storm Alarm
Fire TRAP
Alarm Fire
Threshold
（1～255kpps）
AlarmClear
Threshold
（1～255kpps）
Traffic
[kpps]
Time
Traffic without storm control
Traffic with storm control
Apply Timer
expired
(0～300sec)
Auto Storm Control
Release Timer
expired
(0～300sec)
Storm Alarm
Fire TRAP
StromAlarm
ClearTRAP
TrafficControl
Apply Trap
StromAlarm
ClearTRAP
TrafficControl
Release Trap