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A quick back-of-my hand calculation gives the following data: 100 mbit bit rate is 100 000 000 bits/second (network, so not 1024) A full length ethernet frame is 1518 bytes, 12 144 bits. Transfer of a full packet takes 12144/100000000 seconds, around 0.12 ms. A minimum length ethernet frame is 64 byes, 512 bits. Transfer of a minimal packet takes 512/...


Hmmm... hadn't heard of Smokeping. I use something pretty similar to it (almost identical), though looks like MTR has more field categories for Packet delivery and Jitter statistics.


Jitter less then 5ms is likely to be overwhelmed by any general purpose OS (the scheduling subsystem) on the end of the connection. In general jitter of ~10% of the RTT is reasonable, especially long, contended or unreliable links can obviously affect that.


It seems that both PFSense and m0n0wall support dummynet traffic shaper. dummynet is a tool originally designed for testing networking protocols, and since then used for a variety of applications including bandwidth management. It simulates/enforces queue and bandwidth limitations, delays, packet losses, and multipath effects.


The best way to do this is probably by using the netem kernel module. See here for more detail. It will allow you to do any and all of the above and then some. This has been part of the linux kernel since 2.6, so should be available in just about any distro by now.


It depends on what you're trying to do, but a a general guideline, jitter under several milliseconds (I'd say about 5 ms) is utterly ignorable for most anything you'll be running between the workstations.


I really doubt you're going to notice one twenty thousandth of a second delay in your network communications.


Jitter might be part of calculating the quality of service. This is not limited to VOIP but also for streaming video/audio for instance. You could basically use jitter (and of course other parameters) to get an early warning of worsening service quality. If you compare the measured jitter with the current server load, it might be possible to indicate even ...

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