• C

Max. datasize in (unix) sockets

Hi,

Does anyone know if there's a maximum datasize that can be passed to one call to a sockets send() function?
There's seems to be some limit around 30-40Kb on Linux and less on FreeBSD...
Is there any docs mentioning this?

Thanks

Jan
janmagpetAsked:
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ufolk123Commented:
Hi janmqpet,

This value is protocol dependent.As for example in datagram sockets, if you pass the X bytes UDP datagram to send,It will have to fragment it to different IP packets for delivery.As
On the target machine defragmentation will be requitr to generate the orginal datagram of X size, The limit on size is generally bounded by the protocol to reduce the overhead of largely fragmented UDP data.
Generally the limit is only for UDP based communication.There is no standard limit of SOCK_STREAM sockets.In stream sockets (TCP) the size is limited by the Buffer size of Sending party.You can configure this using setsockopt( SND_BUFFSIZE option).

as MS help says :->
If the data is too long to pass atomically through the underlying protocol, the error WSAEMSGSIZE is returned, and no data is transmitted.
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