Is it possible to alter the TCP receive window size in LabVIEW for Solaris

[Scott McMillan]

We are currently transfer large amounts of data from an embedded PPC board to a LabVIEW 6 application running on a Sun Server. By using the snoop utility on the Sun, I can see that the TCP receive window on the Sun end is quickly filling resulting in the transmission from the embedded side being throttled, reducing our overall throughput. The TCP receive window is defaulting to 8k, how do we increase it size?

[Darren]

Scott,

I am currently checking with R&D to see if they have any suggestions on this matter. I think I know how to change the window size in Windows (it has to do with modifying registry entries), but I couldn't find any information on how to do it with Solaris. I'll let you know when I hear back from R&D.

Thanks for your patience, and have a pleasant weekend.

Sincerely,

Darren Nattinger
Applications Engineer
National Instruments

[Darren]

Hello,

I heard back from R&D about this issue. They indicate that since Solaris uses loadable kernel modules and doesn't require users to recompile/relink the kernel, there may not be any way to change the system default window size. You could, however, write a LabVIEW CIN (or link to a shared library) which takes the LV TCP refnum, looks up the associated socket descriptor, and calls setsockopt on it to change the TCP Window size for the connection. Although it would be rather involved, this is the only way to change the size of which R&D is aware.

I hope this sheds some light on the situation for you. I wish you luck with your application. Have a pleasant weekend.

Sincerely,
Darren Nattinger
Applications Engineer
National Instruments