David Taylor <david-tay...@blueyonder.co.uk.invalid> wrote: > On 11/12/2012 19:35, Rick Jones wrote: > > Handwaving a bit... The query and the response seem to be > > something like 90 bytes (including an Ethernet header). That then > > is 720 bits. At 3 Mbits/s that would be 0.24 milliseconds of > > transmit time. It would then be 0.024 milliseconds on the > > downlink. I suspect that asymmetry is dwarfed by either queueing > > delays (bufferbloat) when either/both are active and/or the rest > > of the delays from your system to the server(s).
> Yes, I see what you mean, but I was thinking of the whole network, > and not simply the up and down speeds. That we have a 10:1 ratio > may suggest how the rest of that ISP's network is configured. The > delays in the cable modem, Samknows box, router and 1 Gb/s switch > are likely to be far in excess of the 0.024 ms and even the 0.24 ms! Well, I have zero direct knowledge of the internals of an ISP these days, but my understanding of the/a rational behind the asymmetry to the home has to do with allocating limited bandwidth/frequency/spectrum on the physical plant from the ISP's end to the home. If the ISP's internal network (beyond the "head end" or what ever it would be called) is built on more standard ethernet-ish things, I would expect there to be equivalent bandwidth in each direction since to my knowledge those things have symmetric bandwidth. Of course that doesn't guarantee symmetric routing... rick jones -- The glass is neither half-empty nor half-full. The glass has a leak. The real question is "Can it be patched?" these opinions are mine, all mine; HP might not want them anyway... :) feel free to post, OR email to rick.jones2 in hp.com but NOT BOTH... _______________________________________________ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
