Rate Limiter; Description Of The Rate Limiter - Hirschmann RS20 User Manual

Network Load Control

8.3 Rate Limiter

8.3.1

Description of the Rate Limiter

To ensure reliable operation at a high level of traffic, the device allows you to
limit the rate of traffic at the ports.
Entering a limit rate for each port determines the amount of traffic the device
is permitted to transmit and receive.
If the traffic at this port exceeds the maximum rate entered, then the device
suppresses the overload at this port.
A global setting enables/disables the rate limiter function at all ports.
Note: The limiter functions only work on Layer 2 and are used to limit the
effect of storms by frame types that the Switch floods (typically broadcasts).
In doing so, the limiter function disregards the protocol information of higher
layers, such as IP or TCP. This can affect on TCP traffic, for example.
To minimize these effects, use the following options:

limiting the limiter function to particular frame types (e.g. to broadcasts,
multicasts and unicasts with unlearned destination addresses) and
receiving unicasts with destination addresses established by the
limitation,
 using the output limiter function instead of the input limiter function
because the former works slightly better together with the TCP flow
control due to switch-internal buffering.
 increasing the aging time for learned unicast addresses.
UM BasicConfig L2E
Release 8.0 05/2013
8.3 Rate Limiter
125