Comments

Episode-2468- Listener Calls for 7-11-19 — 7 Comments

  1. Jack, your response to the guy asking “When is the right time to “call the police”?” seems to be missing.  Thanks for the show.

  2. Regarding 5G and latency:

    The low latency promises of 5G are overblown.  Speed of light is the ultimate limit on latency.  As the saying goes, “The speed of light – Not just a good idea, it’s the law”.

    The speed of light in a vacuum is 186,000 Miles/sec which is a only 11.8in per nanosecond, moving through fiber optic cables it’s even slower at about 8in per nanosecond (interestingly, electrical signals scoot through copper wires fractionally faster).  All of the above are speeds in a perfect world and omit the important point that 2-way communication requires a round trip for data, so only  93,ooo Miles/sec round trip in a vacuum, or 4in/ns over fiber 

    Real world speeds are MUCH slower because data has to transit/relay through many devices on its way from point A to point B, and back.  And that doesn’t include the all important “do some processing at point B and respond with something useful”.

    Simple ping testing here on a cable modem broadband connections shows the following, note I am using 1Gbit wired connections when Wifi and 4G are not specified below…

    Firewall -> cable modem -> company gateway = 8.4ms (note a millisecond = 1million nanoseconds and cable modes are “terrible” in that they take about 6-7ms to propagate data)

    Laptop -> Firewall -> cable modem-> cable company = 8.8ms (relying through my firewall added about .4ms or 400,ooons)

    Laptop -> WiFi -> Firewall -> cable modem-> cable company = 11.9ms (Wifi is adding about 3.1ms or 3.1million ns)

    Similar tests to google.com resulted in…

    Laptop -> Firewall -> cable modem -> cable co -> google = 12.5ms (google is about 4ms “farther away” than my cable company)

    Laptop -> Wifi -> cable modem -> cable co -> google = 12.9ms (Wifi still adding about .4ms)

    Laptop -> Wifi via 4G phone -> cell towner -> google = 34.2ms (phone Wifi and 4G cell system adding 21ms)

    Sorry for the rant, but all this talk about 5G with nanosecond latencies is pure bullshit and drives me nuts.  By the laws of physics 5G cannot be faster than wired connections which require hundreds of thousands to many millions of ns to propagate data.

    Put another way…  If by some magic or alien tech, 5G could induced zero latency, google would still be about 4ms or 4million nanoseconds from me.  That would be nice but would result in, as Jack likes to say, “the square root of fuck all”.

    Yikes!  I don’t normally drink during the week but I might need to break that that habit today.  🙂

     

    • Calm the fuck down, LOL

      If I said nano second I meant micro and simply misspoke. I also never said zero. The actual specs are linked to in response to your other comment.

  3. Thinking I should have started with this…  Internal ping of my laptop, i.e. pinging itself so data essentially going nowhere = .051ms or 51,000 nanoseconds.

    I don’t mean to imply 5G won’t be neat.  It will enable lots of new capabilities, but it cannot violate physics.

    Whiskey-thirty, stepping away from the keyboard for sake of sanity…

  4. Sorry I was channeling my inner Harris 🙂  I worked for 12yrs at a tech company which was very involved in wide area network latency mitigation.

    And to pick one last nit which happens all the time, I flubbed a good number of my responses above by factors of 1000, stabbing my OCD self in the eye.

    You meant milliseconds (ms) 1/1,000th of a sec, not microseconds (µs) is 1/1,000,000th sec cause µs is still too short a time period to get much done.  😉

    Thanks for the link, 4ms average latency for 5G vs the 20ms average for 4G seems plausible, considering my quickie test showed about 21ms of added latency via my 4G phone.  So 5G might deliver 1/5th the latency of 4G which is nice, but not world changing.  It’s the combination of lower latency, higher density, and higher throughput etc. that should result in better overall performance.

    Dammit, this response was supposed to be short! LOL!

    Have a great weekend!  Thanks for the show!

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