Lucent Technologies Stinger, Administration Manual

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Monitoring System and Network Processor operations
Optimizing system performance
Stinger® Administration Guide 4-5
Optimizing performance with filters and flow classification
When filter or packet-flows profiles have been configured, the Stinger system
software must communicate resulting changes in traffic processing requirements to
the underlying system hardware. These updates to the hardware are typically time
intensive, so creating a batch of these requests is recommended to improve the
overall performance of the system (system performance) and to control the rate at
which connections or service is restored to end-users (call performance).
If only ATM PVC or SPVC connections are configured on the system, or if the system
does not support an IP2000 controller, the batch processing parameters are of no
consequence.
For IP traffic that terminates in the Stinger system, filters are applied to the interface
are active as soon as the interface is active.
Overview of
system
profile settings
To enable administrators to batch filter and flow classification updates, the following
parameters, shown with default values, have been added to the
system profile:
[in SYSTEM]
np-update-time = 0
np-default-filtering-policy = forward
Parameter Specifies
np-update-time
Interval (in seconds) at which to communicate filtering
or flow classification updates to the underlying
hardware. Valid values are from 0 to 20.
Note The default value is set to 0 seconds for
backward compatibility, but a setting of between 10-20
seconds is strongly recommended, particularly when a
large number of filter and/or classification rules are
configured on the system.
With a value of 10, updates to the underlying hardware
occur every 10 seconds, so from the time a filtering or
flow classification configuration change is made, a
delay of at most 10 seconds occurs before the change
becomes effective in the underlying hardware.
np-default-filtering-
policy
The default filtering policy ( forward or drop ) to be used
at the input side of the interface during the np-update-
time interval, before the batched hardware update has
been done.
Using the drop policy has an impact on random access
memory size, because the system must create a
forwarding rule for non-filtered connections. So, if
np-
update-time is set to zero, it is strongly recommended
to use the forward policy.
Note A system reset is required for a new value of this
parameter to take effect.