This page will contain information on experiments and proceedures to determine network state. Initial results will focus on back to back tests to understand network dynamics. This will then move on to control lab tests (MB-NG) and then finally full blown WAN tests between selected sites throughout the World.
I may also focus on host performances as well that may affect the rate of data transport. Particularly, hard disk performance, cpu load and requirements and operation systems.
As the number of internet users raise and the implementation of Grid Computing is successfully implemented, internet traffic volume is likely to grow exponentially. As such, it is essential that a set of network performance metrics and measurements be introduced to both the user and network service providers at all levels to provide accurate and common understanding of the performance and reliability of the connections between nodes and how each component of the internet path affects what performance.
Without this understanding, it would difficult to define how QoS policies should be implemented - it would certainly be impossible to police and provision. By standardising and implementing quantitative network performance metrics, intelligent networking decisions and ‘smart’ Grid applications can be developed, this could include:
There have been several research efforts on network performance measurement and analysis, of which the IETF IPPM is a major contributor. In this section, we outline some of the formal metrics that have been devised or are thought to be useful in determining network performance.
In order to obtain information about the network, certain tests may need to be performed. These tests can be broadly classified into two categories:
Active: Where test data is sent through the network in order
to discover the properties of the end-to-end connection.
Passive: Where useful data, such as a required file, is transferred
across the network and the resultant transfer properties used as a test
Most monitoring tools are active, that is we put data in to test out the network. These could be simple pings, or a transfer of data which isn't of any real use to anyone else except for the person conducting the tests (and their audience).
Link Speed in Packet-Switched Networks Robert L. Carter and Mark E.
Crovella, TR-96-006, Boston University Computer Science Department, March
High Performance Data Transfers on Hosts also
bulk transfers over high latency/bandwidth nets @ ORNL.
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