Allied Telesis AT-S63 - Manual (Page 83)

AT-S63 Management Software Web Browser Interface User’s Guide
Section I: Basic Operations 83
For further information about back pressure, refer to Chapter 6, “Port
Parameters,” in the AT-S63 Management Software Menus Interface
User’s Guide.
Flow Control/Back Pressure Limit
Use this parameter to specify the maximum number of ingress packets
that a port receives within a one second period before initiating flow
control or back pressure.A cell equals 128 bytes. The range is 1 to
7935. The default is 7935 cells.
The following three parameters allow you to set rate limiting, the
maximum number of ingress packets a port accepts each second.
Packets exceeding the threshold are discarded.
HOL Blocking
HOL blocking sets a threshold on the utilization of a port’s egress
queue. When the threshold for a port is exceeded, the switch signals
other ports to discard packets to the oversubscribed port. The possible
settings are:
Enabled - HOL blocking prevention is activated.
Disabled - HOL blocking is inactivated on this port.
You also set the rate limit in number of cells. A cell is 128 bytes. The
range is 1 to 8191. The default is 682. For more information about HOL
blocking, refer to Chapter 6, “Port Parameters,” in the AT-S63
Management Software Menus Interface User’s Guide.
Broadcast Rate Limiting
Use this parameter to enable or disable ingress broadcast packet
limits. The possible settings are:
Enabled - Broadcast packet ingress rate limiting is enabled.
Disabled - Broadcast packet ingress rate limiting is disabled. This is
the default.
Broadcast Rate
Use this parameter to set the broadcast rate limit in packets per
second. The range is 0 to 262143. The default is 262143.
Unknown Unicast Rate Limiting
Use this parameter to enable or disable ingress unknown unicast
packet limits. The possible settings are:
Enabled - Unknown unicast packet ingress rate limiting is enabled.
Disabled - Unknown unicast packet ingress rate limiting is disabled.
This is the default.
Unknown Unicast Rate
Use this parameter to set the unknown unicast rate limit in packets per
second. The range is 0 to 262143. The default is 262143.