Abstract

One-page summary of this test. Released before the full report was available. 

NetTest, Inc. commissioned The Tolly Group to evaluate its Fastnet distributed DS3 ATM Probe to determine its sampling frequency, protocol traffic monitoring capabilities and virtual circuit monitoring performance. Additionally, NetTest requested The Tolly Group evaluate a NetScout Systems, Inc. DS3 ATM Probe using the same test criteria.

Summary:

The Tolly Group conducted a competitive evaluation in January 2001 of two DS3 ATM probes: the NetTest Fastnet DS3 ATM Probe and the NetScout Systems DS3 ATM Probe, focusing on their real-time and historical monitoring capabilities. These probes are used to monitor DS3 ATM network links, identify traffic flows and protocols, and track virtual circuits. The tests, sponsored by NetTest, measured key performance metrics such as sampling frequency, protocol detection, and virtual circuit visibility. The NetTest probe reported historical data at 10-second intervals—far more granular than the NetScout probe’s 15-minute intervals. Additionally, the NetTest probe accurately identified 31 unique traffic flows out of a test set of 33, while the NetScout probe identified only five.

A critical aspect of the evaluation was each probe’s ability to detect virtual circuits. The NetTest Fastnet was able to identify all 1,100 virtual circuits immediately in an out-of-the-box configuration. By contrast, the NetScout device could detect only 120, limited by its documented capabilities. Further testing confirmed that NetTest’s device could raise alarms for link activity, utilization, and ILMI status changes as advertised. It also demonstrated the ability to provide round-trip time measurements non-intrusively by analyzing existing traffic, rather than introducing new packets like traditional ping methods.

In summary, the NetTest Fastnet DS3 ATM Probe outperformed the NetScout probe in nearly all categories: faster historical sampling, broader protocol and application traffic recognition, higher virtual circuit detection capacity, and effective alarm functionality. These results support its use in environments requiring granular, real-time monitoring of ATM links. The ability to deploy the device with minimal configuration while achieving full functionality makes it an attractive tool for enterprise network managers aiming to maintain visibility and performance across high-capacity WAN infrastructure.

Note: The company started as a subsidiary of the Danish company, GN Great Nordic. It was divested in 2003 and acquired by Anritsu in 2005. Its products were absorbed into Anritsu.