Kirby Russell » 4pm - September 24, 2010

Basic connectivity testing may be sufficient for best-effort services such as residential Internet access which may not have implicit performance guarantees. For corporate customers who require services with specific performance objectives, it is common to employ the "adopted" RFC 2544 tests. RFC 2544, published in 1999 by the IETF, defines the Benchmarking Methodology for Network Interconnect Devices. It was originally designed to allow the standardized testing and benchmarking of a single interconnect device such as a router or a switch (known as the DUT or Device Under Test). This methodology has become the de facto standard performed routinely in QA labs and verification labs in order to quantify the performance of network devices. In this test scenario, a test system is responsible for injecting traffic into the DUT and then analyzing the frames coming out. By correlating the input and output, the test system can measure the transmission characteristics of the DUT. The RFC 2544 benchmarking methodology defines a series of performance measurements. The following are the four benchmark tests that are most commonly implemented in an automated test suite: Throughput: This test measures the highest data rate at which none of the frames are dropped by the DUT. The following frame sizes in bytes should be used during the test 64, 128, 256, 512, 1024, 1280 and 1518. Latency: Once the throughput has been determined, this test measures the one-way delay through the DUT at the throughput rate. Frame loss: This test measures the frame loss rate throughout the entire range of input data rates and frame sizes. FrameLoss = (InputCount - OutputCount)/InputCount ×100% Back-to-back: This test measures the longest frames burst (frames transmitted with the minimum inter-frame gaps in between) that the DUT can handle without the loss of any frames. Note: In addition to these four tests, RFC 2544 also defines the system recovery test and the reset test which measure the speed at which a DUT recovers from an overload condition and a device reset. These are not used as much mainly because these metrics are typically not part of the carrier SLA. Furthermore, these two tests are also harder to implement in an automated test. In recent years, the RFC 2544 test suite has been adapted to measure the performance of systems and networks. Thus instead of measuring the ability of a switch or router to pass frames, we can now use the same methodology to quantify the transmission characteristics of a virtual circuit or a network. For more details please visit: http://www.sunrisetelecom.com/support/ethernet_white_paper_01.php http://www.ospmag.com/issue/article/carrier-ethernet-profiler%E2%80%A6

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