Rockwell Automation 1783-BMxxx Stratix 5700 Ethernet Managed Switches User Manual - Manual (Page 96)

96 Rockwell Automation Publication 1783-UM004E-EN-P - June 2014
Chapter 3 Switch Software Features
Figure 2 - Port Thresholds Example
The combination of the storm-control suppression level and the 1-second time
interval controls the way the port thresholds algorithm works. A higher threshold
enables more packets to pass through. A threshold value of 100% means that no
limit is placed on the traffic. A value of 0.0 means that all broadcast, multicast, or
unicast traffic on that port is blocked.
Outgoing (rate limiting)
Outgoing port thresholds limit the rate at which the switch communicates with a
client device as a percentage of wire speed (the amount of the rate limit as a
percentage of the total). Limiting bandwidth to specific users and ports helps
control network congestion, enable high performance, create efficient networks,
and prevent a small number of devices from monopolizing network bandwidth.
It can also improve reliability by limiting maximum bandwidth to end devices
that are not be capable of handling large amounts of traffic. From the Device
Manager Web interface or the Logix Designer application AOP, you can enable
or disable rate limiting on a per port basis.
Default Port Thresholds Configuration
By default, incoming unicast, broadcast, and multicast port thresholds are
disabled. Outgoing port thresholds are also disabled.
Total Number of Broadcast
Packets or Bytes
Threshhold
Forwarded Traffic
Blocked Traffic
Time 0 T1 T2 T3 T4 T5
IMPORTANT Because packets do not arrive at uniform intervals, the 1-second time interval
during which traffic activity is measured can affect the behavior of port
thresholds.