#Windows afd socket buffer size driver
#Windows afd socket buffer size Patch

Performance numbers (notice that FileZilla is almost 3 It out for WARFTPd 1.82.0.10 because of the following Running it for and FTP server, but have since swapped To set the default size of the AFD-Windows use the following DWORD registry keys :įileZilla Server 0.9.5 is incredibly slow. The two AFD-Windows should have the same value as the optimal TCPIP-Receive-Window to get the best speed. A small AFD-Receive-Window will constantly be saturating the application receiving data (And blocking the remote sender). A small AFD-Send-Window will constantly be blocking the application sending data. If using a high latency or high bandwidth network then the AFD windows can affect performance. The default size of the two AFD-Windows is configured at boot time and is dependent on the available amount of physical memory: The application creating the socket can use setsockopt to adjust SO_RCVBUF.

#Windows afd socket buffer size Patch

I already searched for the patch to fix this problem. With time, the issue that is described in the 'Symptoms' section occurs if all available socket resources are exhausted.

#Windows afd socket buffer size driver

Receive Window: Acts just like the TCPIP-Receive Window, and when creating a Winsocket over TCPIP, then AFD will use the TCPIP Receive Window as AFD-Receive Window. It also told me the statement below: This issue occurs because of a race condition in the Ancillary Function Driver for WinSock (Afd.sys) that causes sockets to be leaked.

The application creating the socket can use setsockopt to adjust SO_SNDBUF.

Send Window: Used when the application is sending data over a connection, if more data is sent than the receiver is able to acknowledge then the AFD-Send-Window will block the transfer for the application, when it reaches the limit of the AFD-Send-Window.

The AFD uses two windows which acts as a flowcontrol for the application creating the socket: The AFD provides the winsock interface, which is used by most network applications in Windows and is also supporting things like DNS and DHCP. In the WinNT network architecture a layer is placed on top of the TCPIP layer called AFD(Ancillary Function Driver for Winsock). Usually when reading about TCPIP there is only mentioned one Receive Window for a connection, which is used to control congestion created by network latency.