Asyncronous/synchronoug communication: how do the poker clients work?

[matt42s]

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but I do seem to remember reading something about the sequence number should not necessary be sequential (perhaps hashed [for security reasons?]), so it might not always be that easy to do yourself.
Juk [img]/images/graemlins/smile.gif[/img]

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sequence numbers "within" an established session need to be sequential (increment by packet length) - what you read may have been related to a couple of man in the middle exploits a few years back. When a TCP stack uses sequential numbers for different sessions there is a problem.
I can establish a session with a server shortly after you establish a session and can pretty easily guess the sequence numbers your conversation is using. I can then inject packets into your stream and you have no choice but to accept them.
No modern/patched OS uses sequential (or even predictable) sequence numbers for sequential sessions.

As for whether a poker client is synchronous or async - Juk pointed out it depends on what layer you're looking at.
At the physical layer, ethernet is synchronous, at a data link layer, ethernet is asynch - it gets confusing.
Is a poker client sync or async? A poker game is broken if the guy in seat 3 raises, say next Friday - so I say it's synchronous communication.

[YoureToast]

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Is a poker client sync or async? A poker game is broken if the guy in seat 3 raises, say next Friday - so I say it's synchronous communication.

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Thats how I feel when I play at FTP lately.