Palermo Performance Analyzer Concepts

Some of the Palermo Performance Analyzer metrics are unique. Here is quick walkthrough the concepts and related metrics available in the Analyzer.

Limitation Analysis for Throughput

Analyzer classifies each flow according to its own limitation for rate increase:

●  Network Limitation
●  Data Generation Limitation
●  Flow Control Limitation

Aggregating traffic visualization on each of these categories, allows network managers to get useful insight on network capacity and traffic profile.
mostly socialnetwork limited traffic profile graph

Network Limited (red) profile for typical Content Delivery Network downstream traffic.


mostly socialnetwork limited traffic profile graph

Data Generation Limited (green) profile for typical Content Delivery Network upstream traffic.

Throughput for Network Limited Flows

Measuring throughput of individual flows only provides information about network capacity when the flow is Network Limited.
Throughput for Data Generation limited flows or for Flow Control limited flows is related to source and destination resources or application state.
throughput for net limited flows graph

Evolution of average user throughput on Network Limited flows, showing the decrease in available capacity for individual flows at peak hours on downstream traffic.

Retransmissions and Congestion Events

By following state for all connections Analyzer detects all retransmissions, and also explicit congestion notifications.
retransmissions graph

Retransmissions percentage evolution for incoming and outgoing traffic.

Asymmetric Routing

Network configurations may cause large asymmetric routing volume. When the Analyzer observes one sided traffic, it can estimate the unseen traffic volume from the reverse traffic.
This is very useful for route debugging, to anticipate changes in link traffic volume, and to estimate the costs of bad routing policies or configurations.
Analyzer observing only one side of asymmetric traffic

Analyzer observing only one side of asymmetric traffic.


Traffic profile with a large asymmetric percentage

Traffic profile with large percentage of Unseen Traffic, calculated from reverse traffic.

Round Trip Times

Analyzer measures actual round trip times experienced by user connections, caused by the interaction of their congestion control algorithms and their path bottlnecks.
This is extremely useful to detect bufferbloat conditions and to tune active queues, customer policers, etc.
Round trip time concepts

  Two Half Round Trip Times are measured.


mostly socialnetwork limited traffic profile graph

Evolution of aggregate average and minimum Round Trip Times for finished connections, showing their variation with network conditions.

Server Profiling

The Analyzer not only measures networks but also server perfomance. This allows profiling different application response times for individual use cases. It also allows distinguishing between overloaded servers and sistematic application delays.
Server resonse times and individual server response profile

Server average response times list, and indivudual server response time showing characteristic transaction times and load spread.

Taylored and automatic alarms

Analyzer can automatically set alarm thresholds and criteria based on end-user quality of service. They can also be taylored to specific management needs. Alarms encompass end-to-end communications covering broad scopes or fine details of infrastructure and services as needed on each case.
Automatic and taylored alarms

  Automatic and taylored alarms on end-to-end communications.