3 ms·

I worked on a network that used a protocol very similar to ATM (actually it was the first Iridium satellite network). An internet based on ATM would have been a

by vFunct 2y ago

I worked on a network that used a protocol very similar to ATM (actually it was the first Iridium satellite network). An internet based on ATM would have been amazing. You’re basically guaranteeing a virtual switched circuit, instead of the packets we have today. The horror of packet switching is all the buffering it needs, since it doesn’t guarantee circuits. Bandwidth is one thing, but the real benefit is that ATM also guaranteed minimal latencies. You could now shave off another 20-100ms of latency for your FaceTime calls, which is subtle but game changing. Just instant-on high def video communications, as if it were on closed circuits to the next room. For the same reasons, the AI analogy could benefit from both huge processing as well as stronger algorithms.

lxgr 2y ago
> You’re basically guaranteeing a virtual switched circuit Which means you need state (and the overhead that goes with it) for each connection within the network. That's horribly inefficient, and precisely the reason packet-switching won. > An internet based on ATM would have been amazing. No, we'd most likely be paying by the socket connection (as somebody has to pay for that state keeping overhead), which sounds horrible. > You could now shave off another 20-100ms of latency for your FaceTime calls, which is subtle but game changing. Maybe on congested Wi-Fi (where even circuit switching would struggle) or poorly managed networks (including shitty ISP-supplied routers suffering from horrendous bufferbloat). Definitely not on the majority of networks I've used in the past years. > The horror of packet switching is all the buffering it needs [...] The ideal buffer size is exactly the bandwidth-delay product. That's really not a concern these days anymore. If anything, buffers are much too large, causing unnecessary latency; that's where bufferbloat-aware scheduling comes in.
- vFunct 2y ago
  The cost for interactive video would be a requirement of 10x bandwidth, basically to cover idle time. Not efficient but not impossible, and definitely wouldn’t change ISP business models. The latency benefit would outweigh the cost. Just absolutely instant video interaction.
  - foobarian 2y ago
    It is fascinating to think that before digital circuits phone calls were accomplished by an end-to-end electrical connection between the handsets. What luxury that must have been! If only those ancestors of ours had modems and computers to use those excellent connections for low-latency gaming... :-)
  - lxgr 2y ago
    Einstein would like to have a word… And for the little bit of impact queueing latency has (if done well, i.e. no bufferbloat), I doubt anyone would notice the difference, honestly.
    - vFunct 2y ago
      You’re arguing for a reduction in quality in internet services. People do notice those things. It’s like claiming people don’t care about slimmer iPhones. They do.
thijson 2y ago
I remember my professor saying how the fixed packet size in ATM (53 bytes) was a committee compromise. North America wanted 64 bytes, Europe wanted 32 bytes. The committee chose around the midway point.
- wtallis 2y ago
  53 byte frames is what results in the exact compromise of 48 bytes for the payload size.
pjdesno 2y ago
Man, I saw a presentation on Iridium when I was at Motorola in the early 90s, maybe 92? Not a marketing presentation - one where an engineer was talking, and had done their own slides. What I recall is that it was at a time when Internet folks had made enormous advances in understanding congestion behavior in computer networks, and other folks (e.g. my division of Motorola) had put a lot of time into understanding the limited burstiness you get with silence suppression for packetized voice, and these folks knew nothing about it.
eru 2y ago
> The horror of packet switching is all the buffering it needs, since it doesn’t guarantee circuits. You don't actually need all that much buffering. Buffer bloat is actually a big problem with conventional TCP. See eg https://news.ycombinator.com/item?id=14298576 https://news.ycombinator.com/item?id=14298576
richbhanover 2y ago
> ... guaranteed minimal latencies. You could now shave off another 20-100ms of latency for your FaceTime calls... I already do this. But I cheat - I use a good router (OpenWrt One) that has built-in controls for Bufferbloat. See [How OpenWrt Vanquishes Bufferbloat](https://forum.openwrt.org/t/how-openwrt-vanquishes-bufferbloat/189381 https://forum.openwrt.org/t/how-openwrt-vanquishes-bufferblo...)

by vFunct 2y ago

lxgr 2y ago

> You’re basically guaranteeing a virtual switched circuit Which means you need state (and the overhead that goes with it) for each connection within the network. That's horribly inefficient, and precisely the reason packet-switching won. > An internet based on ATM would have been amazing. No, we'd most likely be paying by the socket connection (as somebody has to pay for that state keeping overhead), which sounds horrible. > You could now shave off another 20-100ms of latency for your FaceTime calls, which is subtle but game changing. Maybe on congested Wi-Fi (where even circuit switching would struggle) or poorly managed networks (including shitty ISP-supplied routers suffering from horrendous bufferbloat). Definitely not on the majority of networks I've used in the past years. > The horror of packet switching is all the buffering it needs [...] The ideal buffer size is exactly the bandwidth-delay product. That's really not a concern these days anymore. If anything, buffers are much too large, causing unnecessary latency; that's where bufferbloat-aware scheduling comes in.

vFunct 2y ago
The cost for interactive video would be a requirement of 10x bandwidth, basically to cover idle time. Not efficient but not impossible, and definitely wouldn’t change ISP business models. The latency benefit would outweigh the cost. Just absolutely instant video interaction.
- foobarian 2y ago
  It is fascinating to think that before digital circuits phone calls were accomplished by an end-to-end electrical connection between the handsets. What luxury that must have been! If only those ancestors of ours had modems and computers to use those excellent connections for low-latency gaming... :-)
- lxgr 2y ago
  Einstein would like to have a word… And for the little bit of impact queueing latency has (if done well, i.e. no bufferbloat), I doubt anyone would notice the difference, honestly.
  - vFunct 2y ago
    You’re arguing for a reduction in quality in internet services. People do notice those things. It’s like claiming people don’t care about slimmer iPhones. They do.

thijson 2y ago

I remember my professor saying how the fixed packet size in ATM (53 bytes) was a committee compromise. North America wanted 64 bytes, Europe wanted 32 bytes. The committee chose around the midway point.

wtallis 2y ago
53 byte frames is what results in the exact compromise of 48 bytes for the payload size.

pjdesno 2y ago

Man, I saw a presentation on Iridium when I was at Motorola in the early 90s, maybe 92? Not a marketing presentation - one where an engineer was talking, and had done their own slides. What I recall is that it was at a time when Internet folks had made enormous advances in understanding congestion behavior in computer networks, and other folks (e.g. my division of Motorola) had put a lot of time into understanding the limited burstiness you get with silence suppression for packetized voice, and these folks knew nothing about it.

eru 2y ago

> The horror of packet switching is all the buffering it needs, since it doesn’t guarantee circuits. You don't actually need all that much buffering. Buffer bloat is actually a big problem with conventional TCP. See eg https://news.ycombinator.com/item?id=14298576 https://news.ycombinator.com/item?id=14298576

richbhanover 2y ago

> ... guaranteed minimal latencies. You could now shave off another 20-100ms of latency for your FaceTime calls... I already do this. But I cheat - I use a good router (OpenWrt One) that has built-in controls for Bufferbloat. See [How OpenWrt Vanquishes Bufferbloat](https://forum.openwrt.org/t/how-openwrt-vanquishes-bufferbloat/189381 https://forum.openwrt.org/t/how-openwrt-vanquishes-bufferblo...)