4 ms·

I don't think skipping the handshake is much of a benefit to QUIC. TCP was designed to have long-lived connections. Mobile networks are moving toward keeping yo

I don't think skipping the handshake is much of a benefit to QUIC. TCP was designed to have long-lived connections. Mobile networks are moving toward keeping your external IP consistent between handoffs, handling the routing internally. Fixed networks will connect to servers once every couple of minutes at most. QUIC mostly affects time-to-first-paint, which is mostly of interest for the slowest connections, which is nice, but becoming less and less relevant over time. It's not like speeding up the connectivity time is going to matter when all gains in connectivity time will be used for additional advertising and tracking against the end-user. The main value propositions of QUIC for me are in the encryption earlier in the connection and in the reduced infrastructure usage on the server side.

withinboredom 3y ago
UDP is connectionless, so that aspect isn't even comparable to TCP.
- tonyarkles 3y ago
  I mean, yes, it is but many (not all) protocols built on top of it are generally still “connection-oriented”. QUIC, for example, still results in a “connection” it’s just implemented at the application layer instead of as part of the UDP protocol itself.
  - withinboredom 3y ago
    That still isn't even comparable. The routers along the path of a UDP packet may not even be tracking the flow (unlike in TCP), and keeping it up. A "connection" in TCP is a very big beast, with routers and computers tracking them (conntrack and friends) to keep them alive (or not) and ensure everything runs smoothly. There is none of that with UDP. So yeah, there might be an application-level concept of a connection, but that isn't guaranteed by a single bit of infrastructure on the internet.
    - oasisbob 3y ago
      Internet routers at large are not doing connection tracking. If a device is dropping the ball on connection tracking, it's almost certainly in your own network. Your ISP may have carrier-grade NAT. The content provider network probably has stateful load balancers. Those devices need to keep state, but they would need to do so with QUIC and UDP quasi-connections too.
      - withinboredom 3y ago
        Most (if not all) ISP routers (outside your business/house) employ connection tracking. This is used to monitor bandwidth usage, implement firewalls (aka, port 25/80/443), among other things.
        oasisbob 3y ago
        Absolutely not. Most routers on the internet are not doing connection tracking. But that's not my point - most cases where things /are/ keeping state need to worry about keeping state on UDP-oriented protocols as well.
        tonyarkles 3y ago
        Yeah, 100% agree. The main place that connection tracking is happening is whenever there's NAT involved and that's going to need to happen for both TCP and UDP.
    - tuetuopay 3y ago
      If the equipment does connection tracking for TCP, then it most certainly does for UDP. Raw UDP does not have the notion of stream, but it most certainly does have flows. If the equipment does it for TCP, id does it for UDP. However most routers don't do connection tracking at all. That is way too expensive at scale for zero benefits. Take your transit provider, it has tens of terabits of data per second, and those can be handled by a single router. That's a buttload of different stream for a single device, and connection tracking is expensive to do. I can say for experience that connection tracking tables for a single hypervisor with VMs can reach gigabytes. For a single node. Now extrapolate that to a backbone router. It's not happening.
- deleted 3y ago
  [deleted]
bdd8f1df777b 3y ago
> QUIC mostly affects time-to-first-paint, which is mostly of interest for the slowest connections, which is nice, but becoming less and less relevant over time. You give no reasoning for it being less and less relevant. It is very relevant to me, where every connection to the US has 300ms RTT.
- AnthonyMouse 3y ago
  And assuming that's because you're on another continent, that problem is intractable because it's a consequence of the speed of light. You're never going to have a 10ms round trip between Los Angeles and Australia.
  - adwn 3y ago
    I think OP's point is that QUIC needs fewer round trips than TCP+TLS to set up a connection.
  - bmicraft 3y ago
    You really didn't understand the point they were making. 300ms rtt is much less bad when quic merges handshake and key exchange, requiring less round trips even before 0rtt session resumption
    - AnthonyMouse 3y ago
      Of course it is, that's the point. You need to reduce the number of round trips because physics doesn't allow you to reduce the round trip time no matter how sophisticated your transistors.
      - bastawhiz 3y ago
        Reducing the number of rounds trips is exactly what quic does
        AnthonyMouse 3y ago
yencabulator 3y ago
> Mobile networks are moving toward keeping your external IP consistent between handoffs, handling the routing internally. That doesn't help for a phone bouncing between wifi and cellular.

withinboredom 3y ago

UDP is connectionless, so that aspect isn't even comparable to TCP.

tonyarkles 3y ago
I mean, yes, it is but many (not all) protocols built on top of it are generally still “connection-oriented”. QUIC, for example, still results in a “connection” it’s just implemented at the application layer instead of as part of the UDP protocol itself.
- withinboredom 3y ago
  That still isn't even comparable. The routers along the path of a UDP packet may not even be tracking the flow (unlike in TCP), and keeping it up. A "connection" in TCP is a very big beast, with routers and computers tracking them (conntrack and friends) to keep them alive (or not) and ensure everything runs smoothly. There is none of that with UDP. So yeah, there might be an application-level concept of a connection, but that isn't guaranteed by a single bit of infrastructure on the internet.
  - oasisbob 3y ago
    Internet routers at large are not doing connection tracking. If a device is dropping the ball on connection tracking, it's almost certainly in your own network. Your ISP may have carrier-grade NAT. The content provider network probably has stateful load balancers. Those devices need to keep state, but they would need to do so with QUIC and UDP quasi-connections too.
    - withinboredom 3y ago
      Most (if not all) ISP routers (outside your business/house) employ connection tracking. This is used to monitor bandwidth usage, implement firewalls (aka, port 25/80/443), among other things.
      - oasisbob 3y ago
        Absolutely not. Most routers on the internet are not doing connection tracking. But that's not my point - most cases where things /are/ keeping state need to worry about keeping state on UDP-oriented protocols as well.
        tonyarkles 3y ago
        Yeah, 100% agree. The main place that connection tracking is happening is whenever there's NAT involved and that's going to need to happen for both TCP and UDP.
  - tuetuopay 3y ago
    If the equipment does connection tracking for TCP, then it most certainly does for UDP. Raw UDP does not have the notion of stream, but it most certainly does have flows. If the equipment does it for TCP, id does it for UDP. However most routers don't do connection tracking at all. That is way too expensive at scale for zero benefits. Take your transit provider, it has tens of terabits of data per second, and those can be handled by a single router. That's a buttload of different stream for a single device, and connection tracking is expensive to do. I can say for experience that connection tracking tables for a single hypervisor with VMs can reach gigabytes. For a single node. Now extrapolate that to a backbone router. It's not happening.
deleted 3y ago
[deleted]

bdd8f1df777b 3y ago

> QUIC mostly affects time-to-first-paint, which is mostly of interest for the slowest connections, which is nice, but becoming less and less relevant over time. You give no reasoning for it being less and less relevant. It is very relevant to me, where every connection to the US has 300ms RTT.

AnthonyMouse 3y ago
And assuming that's because you're on another continent, that problem is intractable because it's a consequence of the speed of light. You're never going to have a 10ms round trip between Los Angeles and Australia.
- adwn 3y ago
  I think OP's point is that QUIC needs fewer round trips than TCP+TLS to set up a connection.
- bmicraft 3y ago
  You really didn't understand the point they were making. 300ms rtt is much less bad when quic merges handshake and key exchange, requiring less round trips even before 0rtt session resumption
  - AnthonyMouse 3y ago
    Of course it is, that's the point. You need to reduce the number of round trips because physics doesn't allow you to reduce the round trip time no matter how sophisticated your transistors.
    - bastawhiz 3y ago
      Reducing the number of rounds trips is exactly what quic does
      - AnthonyMouse 3y ago

yencabulator 3y ago

> Mobile networks are moving toward keeping your external IP consistent between handoffs, handling the routing internally. That doesn't help for a phone bouncing between wifi and cellular.