5 ms·

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”

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.

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.