Cisco Cisco Packet Data Interworking Function (PDIF) Documentation Roadmaps
PDG/TTG Overview
▀ Features and Functionality
▄ Cisco ASR 5000 Series Product Overview
OL-22937-01
Congestion Control
Congestion control allows you to set policies and thresholds and specify how the system reacts when faced with a heavy
load condition.
load condition.
Congestion control monitors the system for conditions that could potentially degrade performance when the system is
under heavy load. Typically, these conditions are temporary (for example, high CPU or memory utilization) and are
quickly resolved. However, continuous or large numbers of these conditions within a specific time interval may have an
impact the system‘s ability to service subscriber sessions. Congestion control helps identify such conditions and invokes
policies for addressing the situation.
under heavy load. Typically, these conditions are temporary (for example, high CPU or memory utilization) and are
quickly resolved. However, continuous or large numbers of these conditions within a specific time interval may have an
impact the system‘s ability to service subscriber sessions. Congestion control helps identify such conditions and invokes
policies for addressing the situation.
Congestion control operation is based on configuring the following:
Congestion Condition Thresholds: Thresholds dictate the conditions for which congestion control is enabled
and establishes limits for defining the state of the system (congested or clear). These thresholds function in a
way similar to operation thresholds that are configured for the system as described in the Thresholding
Configuration Guide. The primary difference is that when congestion thresholds are reached, a service
congestion policy and an SNMP trap, starCongestion, are generated.
way similar to operation thresholds that are configured for the system as described in the Thresholding
Configuration Guide. The primary difference is that when congestion thresholds are reached, a service
congestion policy and an SNMP trap, starCongestion, are generated.
A threshold tolerance dictates the percentage under the configured threshold that must be reached in order for the
condition to be cleared. An SNMP trap, starCongestionClear, is then triggered.
condition to be cleared. An SNMP trap, starCongestionClear, is then triggered.
Port Utilization Thresholds: If you set a port utilization threshold, when the average utilization of all ports in
the system reaches the specified threshold, congestion control is enabled.
Port-specific Thresholds: If you set port-specific thresholds, when any individual port-specific threshold is
reached, congestion control is enabled system-wide.
Service Congestion Policies: Congestion policies are configurable for each service. These policies dictate how
services respond when the system detects that a congestion condition threshold has been crossed.
Important:
For more information on congestion control, refer to the System Enhanced Feature Configuration
Guide.
Bulk Statistics
Bulk statistics allow operators to choose to view not only statistics that are of importance to them, but also to configure
the format in which it is presented. This simplifies the post-processing of statistical data since it can be formatted to be
parsed by external, back-end processors.
the format in which it is presented. This simplifies the post-processing of statistical data since it can be formatted to be
parsed by external, back-end processors.
When used in conjunction with the Web Element Manager, the data can be parsed, archived, and graphed.
The system can be configured to collect bulk statistics (performance data) and send them to a collection server (called a
receiver). Bulk statistics are statistics that are collected in a group. The individual statistics are grouped by schema. The
following is a partial list of supported schemas:
receiver). Bulk statistics are statistics that are collected in a group. The individual statistics are grouped by schema. The
following is a partial list of supported schemas:
System: Provides system-level statistics
Card: Provides card-level statistics
Port: Provides port-level statistics
PDG: Provides PDG service statistics