message lengths Winsock2 TCp/Ip

hi,

are there any general guidlines for the size of a message that should be send over TCP/Ip using winsock2. e.g I have a structue of max size 3461760 bytes. Can be be sent over tcp/ip as a message to an application as one single message.

What are the issues with using recv ( winsock2 ) and datalengths, if there are any.

Can anyone point me to a an article which can explain this. I am new to network programmign basically with zero training and have to research on my own to write a set of network applications.

Thnx for help.

Interesting.

check out getsockopt() and SO_SNDBUF. i read something about 8192 default buffer size

Kuphryn

isn't this one for unix thou? all the articles abt it mention unix. My apps are gonan run on windows and use winsock2

sorry yeah it is for winsock too.

Okie let's assume that the data i wanna send is larger then that value. How do you deal witht his kinda thing when the message is recieved by client/server? am tempted to use recv( well dunno abt anything else )

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Originally Posted by venAdder

are there any general guidlines for the size of a message that should be send over TCP/Ip using winsock2. e.g I have a structue of max size 3461760 bytes. Can be be sent over tcp/ip as a message to an application as one single message.

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yes, the buffer can be sent all at once, with one call to send(). This is a simple technique usable when there is only one (or, at most a few) transmissions, such as between a single server and a single client.

This approach does not scale well, however, if there are many transmission (or many clients being served), since then you must allocate many large-sized buffers. so, in this case, one approach is to break the transmission into blocks of reasonable size, and send only one block at a time. The definition of "reasonable" will vary based on your specific application. Frequently-used numbers are 4k and 8k.

Quote:

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Originally Posted by venAdder

What are the issues with using recv ( winsock2 ) and datalengths, if there are any.

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Same issue as above (memory allocation for the receive buffer), plus another: responsiveness. If you try to receive one single huge buffer, then you will typically wait until the entire buffer is received, which might take a long time during which nothing else happens. On the other hand, if you receive multiple smaller buffers, then at least something is happening periodically, such as the accumulation of a received file to permanent storage on a disk.

Quote:

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Originally Posted by venAdder

Can anyone point me to a an article which can explain this. I am new to network programmign basically with zero training and have to research on my own to write a set of network applications.

Thnx for help.

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I listed a few links at your other post.

Mike

Thanx Mike, it did help me a lot , I am gonan keep exploring into this till i get it all straightened out . Thnx again for you help.