What would happen if we didn't use TCP or UDP?
1–10 of 116 posts
Re: What would happen if we didn't use TCP or UDP?
#2You don't need to make up your own for this experiment. There's already a pretty old protocol that's far superior to TCP, but failed to get adoption because of network hardware dropping everything other than TCP and UDP. It's called SCTP.
Re: What would happen if we didn't use TCP or UDP?
#3What you want is a packet socket:
sock_raw = socket(AF_PACKET , SOCK_RAW , htons(ETH_P_ALL));
Re: What would happen if we didn't use TCP or UDP?
#4You don't need to make up your own for this experiment. There's already a pretty old protocol that's far superior to TCP, but failed to get adoption because of network hardware dropping everything other than TCP and UDP. It's called SCTP.
SCTP is really cool, I first found out about it because it’s the basis for WebRTC data channels. It’s basically reliable UDP, but you can turn off the reliability if you want. Makes me wonder why QUIC exists when SCTP does…
Re: What would happen if we didn't use TCP or UDP?
#5You don't need to make up your own for this experiment. There's already a pretty old protocol that's far superior to TCP, but failed to get adoption because of network hardware dropping everything other than TCP and UDP. It's called SCTP.
SCTP is really cool, I first found out about it because it’s the basis for WebRTC data channels. It’s basically reliable UDP, but you can turn off the reliability if you want. Makes me wonder why QUIC exists when SCTP does…
> why QUIC exists when SCTP does
Because QUIC uses UDP, which is supported by most/all intermediate routing equipment.
Re: What would happen if we didn't use TCP or UDP?
#6Earlier quoted context omitted.
SCTP is really cool, I first found out about it because it’s the basis for WebRTC data channels. It’s basically reliable UDP, but you can turn off the reliability if you want. Makes me wonder why QUIC exists when SCTP does…
> why QUIC exists when SCTP does Because QUIC uses UDP, which is supported by most/all intermediate routing equipment.
Is this a real issue? SCTP runs over IP, so unless your talking about firewalls and such, the support should be there.
Edit: a quick search showed that NAT traversal is an issue (of course!)
Re: What would happen if we didn't use TCP or UDP?
#7Earlier quoted context omitted.
> why QUIC exists when SCTP does Because QUIC uses UDP, which is supported by most/all intermediate routing equipment.
Is this a real issue? SCTP runs over IP, so unless your talking about firewalls and such, the support should be there. Edit: a quick search showed that NAT traversal is an issue (of course!)
Hole punching is perhaps why UDP is de facto?
Re: What would happen if we didn't use TCP or UDP?
#8What you want is a packet socket: sock_raw = socket(AF_PACKET , SOCK_RAW , htons(ETH_P_ALL)); IP networks should forward anything, but NAT is a major problem. Would be interesting to try with IPv6.
That's very interesting!
I'll try out IPv6
Re: What would happen if we didn't use TCP or UDP?
#9You don't need to make up your own for this experiment. There's already a pretty old protocol that's far superior to TCP, but failed to get adoption because of network hardware dropping everything other than TCP and UDP. It's called SCTP.
SCTP is fascinating because it's one of the backbone technologies that makes communication possible for most people on the planet (as the mobile network stack pretty much relies on it), yet it's effectively unsupported on almost every consumer device. If you want to use it, you're probably going to have to ship a userland implementation that needs privileges to open a raw network socket, because kernel implementations are rare (and often slow).
We could've had it as a QUIC replacement if it weren't for terrible middleboxes and IPv4 NAT screwing everyone over once again. Hell, NAT wouldn't even have been an issue had SCTP support been widespread before consumer NAT devices started being implemented.
It's a prime example of how new network protocols now have to lie and deceive to work over the internet. TLS needs to pretend to be TLS 1.2, QUIC needs to pretend to be an application on top of UDP while reimplementing SCTP and TCP, and even things like secure DNS are now piped over HTTPS just in case a shitty middlebox can't deal with raw TLS.
Re: What would happen if we didn't use TCP or UDP?
#10Earlier quoted context omitted.
> why QUIC exists when SCTP does Because QUIC uses UDP, which is supported by most/all intermediate routing equipment.
Is this a real issue? SCTP runs over IP, so unless your talking about firewalls and such, the support should be there. Edit: a quick search showed that NAT traversal is an issue (of course!)
Yes this is called protocol ossification [1] or ossification for short. Other transport layer protocol rollouts have been stymied by ossification such as MPTCP. QUIC specifically went with UDP to prevent ossification yet if you hang out in networking forums you'll still find netops who want to block QUIC if they can.