On Wed, 02 Nov 2011 17:17:07 +0100, Jens Mueller wrote: > should set it to 10 MiB; > I'm unsure about the socket option level. There is also > SocketOptionLevel.IP. > Yes Jens, that's what I thought, and that approach does indeed change the buffer size, but not by anything close to what you ask for. I've tried both SOCKET and IP. Steve