Setting Congestion Thresholds; Configuring Ports - 3Com SuperStack II PathBuilder S330 Reference Manual

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HAPTER ONFIGURING
Configuring Ports
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ATH UILDER
When you select one of these options, a prompt appears at the bottom of the
screen, allowing you to enter a new threshold in the range 0% to 100%. When
the buffer reaches the Congestion On threshold, the congestion filter is on. When
the buffer falls below the Congestion Off threshold, the congestion filter is off.
For example, if you set Congestion On to 75% and Congestion Off to 50%, the
congestion filter is on when the buffer is 75% full and is off when the buffer drops
below 50% full.
See "Setting Congestion Thresholds" below for further details about congestion
thresholds.
CAUTION: You should enable early packet discard for AAL5 traffic only.
8 Select [4] Previous Menu to return to the CTX Buffers menu.
9 Press [Esc] to return to the CTX menu.
10 Select [3] Apply CTX Buffer Changes to apply your settings.
CAUTION: This operation will affect traffic.

Setting Congestion Thresholds

For every connection where early packet discard is enabled, a status is kept when
there is a partial packet for that connection in the queue. Once the queue cell level
exceeds the Congestion On thresholds, only connections with partial packets
already existing in the queue are allowed in. Cells from other connections are
dropped. Once the congestion has subsided to the Congestion Off level, then all
remaining connections are allowed.
Set the Congestion On threshold based on the maximum packet size expected and
the number of active connections sending packets at a particular instant based on
a probability model.
Set the Congestion On level to allow some hysteresis in the operation.
The PathBuilder S330/S310 ports each have an administrative and an operational
status. To set up a virtual circuit, you must first set the administrative status of the
port which will carry the circuit online to In Service. You can also configure other
parameters, depending on the type of port.
When you set the administrative status to Out of Service, the operational status is
set to Out of Service whether or not the port is actually operational or not. Once
you set the administrative status to In Service (online), the operational status will
indicate the true port status (Out of Service if there is a port failure, or In Service if
not).
The following sections tell you how to configure specific ports on the PathBuilder
S330/S310.
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ODULES ORTS AND PPLICATIONS