how to change max tcp buffer?

QNX USERS QNX2 and QNX4
1

Hello,

We have to support WAN access to our remote site running QNX. We would like to increase the max tcp buffer in order to increase throughtput from there to us. (It did a world of good for our Linux machines).
Any idea how to do this in QNX4.25 ?

Ta,

Doro

2

on a per socket basis you can do it with
setsockopt(s, SOL_SOCKET, SO_SNDBUF, &bufsize, sizeof(bufsize));
setsockopt(s, SOL_SOCKET, SO_RCVBUF, &bufsize, sizeof(bufsize));

On a globab basis look at the net.inet.tcp.sendspace /
net.inet.tcp.recvspace sysctls (sysctl utility). Note I’m
not positive QNX4 had these sysctls.

3

Thank you for this, but unfortunately, QNX4 doesn’t have the sysctl mechanism. Anyone out there who at least could tell me what the default tcp buffer size is?

4

Do the corresponding getsockopt() to get the defaults.

-seanb