[sldev] UDP to TCP/HTTP - performance issues?

[John Hurliman]

Argent Stonecutter wrote:
> TCP is only more costly than UDP if you don't need reliable delivery 
> and event ordering. If you do, it's cheaper to use TCP than to fake it 
> in UDP. TCP traffic overhead is on the order of half a dozen packets 
> per *session*.
>
> It shouldn't be possible to "overload the network stack" at internet 
> speeds on any computer that can run SL at all. We're talking about 
> traffic three decimal orders of magnitude below the level where people 
> have seen network problems on Vista with "secure audio path" running - 
> and that was considered a flaw in the network stack. I can't imagine a 
> network stack so badly broken that this would be an issue.
>
> I would assume that LL implements this with some small number of 
> persistent TCP connections and the server uses whichever one doesn't 
> return EWOULDBLOCK as the one to assign each new stream of data to.

Actually a single persistent connection is held open from the 
client->server for the purpose of receiving server-initiated event 
messages, and new connections are opened from client->server which the 
server replies to and then the connection is closed.

John Hurliman