Re: Socket differences between localhost and LAN (or Internet)

"Scott McPhillips [MVP]" <org-dot-mvps-at-scottmcp>
Fri, 08 Sep 2006 11:26:12 -0400
Wyvern wrote:

The value returned by recv is not guaranteed to be the packet size.
Always check that return, and call again if you need more data. On the
local host it will typically be the packet size, but over the network
you are more likely to encounter different recv sizes.

Scott McPhillips [VC++ MVP]

But why ? It's TCP, I expect that if I send 1024 bytes, I receive 1024
bytes; if what I send is not what I receive it is a very big trouble, I
don't understand. WHy in a network those values are different ? WHat
can I do ? What if I try to "reask" for the missing data but the
dimension of missing data doesn't come correctly to the server ? In
this case it would be a complete tragedy...

Your expectations or assumptions are completely wrong. This is a
classic beginner's mistake. You can reliably receive the bytes, but
only if you understand the winsock interface. Study the way winsock
really works:

Scott McPhillips [VC++ MVP]

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