You can tune Ad Hoc Transfer (AHT) upload and download performance by changing the AHT buffer sizes in the AHT\web.config file. Increasing buffer sizes generally improves throughput; however, setting buffers too large for the available system memory can lead to out‑of‑memory errors. The default size is 256 KB.

Important: Back up web.config before you make changes so that you can quickly roll back if needed.

Edit the buffer sizes

  1. Navigate to the AHT folder on the WS_FTP Server: C:\Program Files (x86)\Progress\WS_FTP Server\Ad Hoc Transfer\AHT\web.config. Your environment may differ if you chose a non‑default path.
  2. Open web.config in a text editor.
  3. Search for and edit the values of UPLOADBUFFER and DOWNLOADBUFFER to the desired sizes.
  4. Save the file and restart IIS to apply changes.