4 ms·

Actually, even TCP is going to be replaced. I just want to remind the initial work of Google on QUIC, which now has become some standard. It is based on UDP and

Actually, even TCP is going to be replaced. I just want to remind the initial work of Google on QUIC, which now has become some standard. It is based on UDP and re-defining TCP features based on UDP together with cryptography and by allowing IP changes to allow moving clients.

speed_spread 3y ago
TCP is fine and isn't going anywhere. QUIC is an overengineered contraption that only exists to serve more ads. SSH doesn't need it. Postgres doesn't need it. Nobody needs QUIC except Google.
- neysofu 3y ago
  QUIC is not without defects, I'm with you there, but almost almost any "web-scale" company dealing with a lot of cellular connections would disagree with your statement. Uber, Verizon, Cloudflare, Meta, Fastly, among others, some of which have reported very significant latency reductions.
- yencabulator 3y ago
  > SSH doesn't need it. SSH's "master" mode connection sharing would benefit from QUIC / HTTP/3 head of line blocking elimination just as much as browsers would. Run a heavy rsync using connection sharing with an interactive session and you'll notice the interactive sessions latency suffering noticably. Long-lived SSH connections would benefit from QUIC / HTTP/3 session survivability.
londons_explore 3y ago
And yet, even with QUIC and a brand new Google phone on a Google wifi network and a Google Fi cell connection, I still can't walk away from my house and have a video call migrate from wifi to 5G without the audio glitching and dropping frames. All the mobility benefits of QUIC mean nothing when the rest of the software stack isn't designed to let it work.
- 867-5309 3y ago
  that's never going to be a seamless transition. the fact the transition happens automatically is a marvel in itself
  - londons_explore 3y ago
    It 100% could be. Changes you'd need are: * Android lets an application talk over both wifi and 5G at the same time. * Android exposes information about signal strength on a per packet basis, so that the application can decide at some point that too many packets are too close to not being received, so it's time to send data over 5G in addition. It should also expose data about packet retransmissions at the physical layer (ie. collisions and backoff times due to another device using the media). * When the 5G data flow is established and channel parameters like delay and loss are characterized, then stop sending data over wifi. * And since this process never involved delaying any data by a roundtrip, nor any packet loss, there is no need to drop any frames. Note that the cell network has been able to handoff voice calls from one cell tower to another without glitches since the 80's!.
    - crazygringo 3y ago
      I think the factor you're missing is that the WiFi and 5G connections may have substantially different latencies to the other person. Going from a lower-latency to a higher-latency connection will always involve audio dropping out and video pausing. And in the opposite direction, it's preferable to skip over a few frames in order to reduce latency, rather than maintain higher latency. I wonder if you don't see this with cell phones because the latency is generally identical, or if it's just less noticeable with audio than with video? I guess I'd also wonder if cell towers really do hand off without glitches, since there always seem to be glitches when you're driving, but you don't have the slightest idea whether they're from tall buildings or interference or Bluetooth or handoffs or what, or even on your end or the other person's end.
      - londons_explore 3y ago

speed_spread 3y ago

TCP is fine and isn't going anywhere. QUIC is an overengineered contraption that only exists to serve more ads. SSH doesn't need it. Postgres doesn't need it. Nobody needs QUIC except Google.

neysofu 3y ago
QUIC is not without defects, I'm with you there, but almost almost any "web-scale" company dealing with a lot of cellular connections would disagree with your statement. Uber, Verizon, Cloudflare, Meta, Fastly, among others, some of which have reported very significant latency reductions.
yencabulator 3y ago
> SSH doesn't need it. SSH's "master" mode connection sharing would benefit from QUIC / HTTP/3 head of line blocking elimination just as much as browsers would. Run a heavy rsync using connection sharing with an interactive session and you'll notice the interactive sessions latency suffering noticably. Long-lived SSH connections would benefit from QUIC / HTTP/3 session survivability.

londons_explore 3y ago

And yet, even with QUIC and a brand new Google phone on a Google wifi network and a Google Fi cell connection, I still can't walk away from my house and have a video call migrate from wifi to 5G without the audio glitching and dropping frames. All the mobility benefits of QUIC mean nothing when the rest of the software stack isn't designed to let it work.

867-5309 3y ago
that's never going to be a seamless transition. the fact the transition happens automatically is a marvel in itself
- londons_explore 3y ago
  It 100% could be. Changes you'd need are: * Android lets an application talk over both wifi and 5G at the same time. * Android exposes information about signal strength on a per packet basis, so that the application can decide at some point that too many packets are too close to not being received, so it's time to send data over 5G in addition. It should also expose data about packet retransmissions at the physical layer (ie. collisions and backoff times due to another device using the media). * When the 5G data flow is established and channel parameters like delay and loss are characterized, then stop sending data over wifi. * And since this process never involved delaying any data by a roundtrip, nor any packet loss, there is no need to drop any frames. Note that the cell network has been able to handoff voice calls from one cell tower to another without glitches since the 80's!.
  - crazygringo 3y ago
    I think the factor you're missing is that the WiFi and 5G connections may have substantially different latencies to the other person. Going from a lower-latency to a higher-latency connection will always involve audio dropping out and video pausing. And in the opposite direction, it's preferable to skip over a few frames in order to reduce latency, rather than maintain higher latency. I wonder if you don't see this with cell phones because the latency is generally identical, or if it's just less noticeable with audio than with video? I guess I'd also wonder if cell towers really do hand off without glitches, since there always seem to be glitches when you're driving, but you don't have the slightest idea whether they're from tall buildings or interference or Bluetooth or handoffs or what, or even on your end or the other person's end.
    - londons_explore 3y ago