SDL Wiki
(This function is part of SDL_net, a separate library from SDL.)


Send a single UDP packet to the specified channel.

Header File

Defined in <SDL_net.h>


int SDLNet_UDP_Send(UDPsocket sock, int channel, UDPpacket *packet);

Function Parameters

UDPsocket sock the UDP socket to send packets on.
UDPpacket * packet a single packet to send to the network.

Return Value

(int) Returns 1 if the packet was sent, or 0 on error.


If the channel specified is -1, the packet will be sent to the address in the src member of the packet.

The packet will be updated with the status of the packet after it has been sent.

Warning: UDP is an unreliable protocol, which means we can report that your packet has been successfully sent from your machine, but then it never makes it to its destination when a router along the way quietly drops it. If this happens--and this is a common result on the internet!--you will not know the packet never made it. Also, packets may arrive in a different order than you sent them. Plan accordingly!

Warning: The maximum size of the packet is limited by the MTU (Maximum Transfer Unit) of the transport medium. It can be as low as 250 bytes for some PPP links, and as high as 1500 bytes for ethernet. Different sizes can be sent, but the system might split it into multiple transmission fragments behind the scenes, that need to be reassembled on the other side (and the packet is lost if any fragment is lost in transit). So the less you can reasonably send in a single packet, the better, as it will be more reliable and lower latency.


This function is available since SDL_net 2.0.0.

CategoryAPI, CategoryAPIFunction

[ edit | delete | history | feedback | raw ]

[ front page | index | search | recent changes | git repo | offline html ]

All wiki content is licensed under Creative Commons Attribution 4.0 International (CC BY 4.0).
Wiki powered by ghwikipp.