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ONX-220 User's Guide
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Chapter 6 Data Testing
Server scaling
When configured as recommended above, one server can support multiple simultaneous
ONX Speed Check tests. The scaling of this server should be based on two aspects:
1. First, the network connection to the server must be capable of supplying data
rates necessary to support the number of concurrent tests. For example, if the
server is connected to a 1 Gb/s network link, it could theoretically support up to 10
simultaneous tests of 100 Mb/s. Likewise, if the server is connected to a 10 Gb/s
network connection, the server could theoretically support up to 100 simultaneous
tests of 100 Mb/s.
2. The second aspect of the scaling algorithm is the processing power and network
efficiency of the server. It is difficult for the server to utilize 100% of the theoretical
network bandwidth. There are inefficiencies in the HW drivers, network stacks, and
protocols, as well as the processing power, that will generally prohibit a server from
supporting theoretical network performance.
It is recommended that modern server class machines be used and that the overall
expectation of this server is to provide 75%-80% of the theoretical maximum. For
instance, assume that a modern-day server connected to a 10 Gb/s link could provide
7.5 Gb/s - 8 Gb/s combined test capacity.
Server over-provisioning
In most cases the ONX meters will not be performing Speed Check testing at the same
time. The Speed Check test runs ~30 seconds and then stops. The probability that a fleet of
technicians will be running a large number of tests simultaneously (in the same 30 seconds
window) is typically low. Therefore, depending on the workflow of the technicians, we can
estimate the number of ONX instruments that can be supported by a single server.
For instance, if the test workflow requires a technician to run the Speed Check test and
the overall workflow time (time between tests) is only a few minutes, then the over-
provisioning should be relatively low as the workflow time is a small multiple of the
Speed Check test time. However, if the workflow time is longer, then the probability of
simultaneous tests becomes much lower and the server over-provisioning could be higher.