Is broadcasting via TCP possible?

c networking tcp broadcast sockets
Anthony picture Anthony · Nov 28, 2010 · Viewed 41.4k times · Source

I'm writing a server/client system in C, which uses BSD Sockets under a TCP connection. The server is multi-threaded, with each connection running in its own receptor. Each client does a good job talking with the server on a one-to-one basis, sadly I can't think of a way to implement a SendToAll() function, for instance, if client A does something that requires sending a packet to all of the clients. How would I do this?

I was considering implementing a queue in every receptor, and any broadcast gets sent to those queues; when the receptor sends out a new packet, it adds that message onto the packet as well, if that makes any sense.

But yeah, is there any way to broadcast via TCP, like you can via UDP?

Answer

shf301 picture shf301 · Nov 28, 2010

As everyone has said that is not possible with TCP, it is unicast only. However there are implementations of reliable multicast, which should give you multicast with the reliability of TCP. See wikipedia, especially Pragmatic General Multicast.

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