On May 3, 2010, at 9:19 PM, Patrick Giagnocavo wrote: >> - do ISPs typically use token bucket filters with large bursts to shape >> traffic? >> - what kind of burst sizes and latencies/limits are typically used for >> the filter? >> > > You will definitely have to account for latency. > > For emulating cable traffic, latencies (in the USA) will be about > 60-80ms to typical sites. Burst mode in my experience occurs only for > about the first 15 seconds, then is throttled back (though not always; > seems to depend on time of day). >
And queues of 1 second at line rate are not uncommon, so if you load the link, things lag. > For DSL, I seem to recall latency being about 90-110ms (note, I haven't > used DSL in many years). Burst mode was generally not noticeable or > available, that is, you got the same speed regardless of downloading a > 1MB jpeg or a 640MB .iso file. Now more typically 40ms. And yeah, no bursts over normal line rate. Most turn down line rate for other plans, not shape.
