Troubleshooting stream transfers

Multicast transfer fails with "Error: Empty file list from file/stdin"

This error might indicate that the transfer user has a docroot set in aspera.conf, which is not supported for multicast-to-multicast transfers. See Using Ascp4 for streaming video.

Transfer from macOS fails

To diagnose the problem, rerun the stream transfer with the logging level set to debug by adding -DD to the command. After the transfer fails, open the log file (homedir/Library/Logs/Aspera/) and search for an ERR response.

"ERR udp_io_open: failed to set rcvbugsz=10485760 (e=55)(ENOBUFS)"

This error indicates that the socket buffer size on the Mac computer is too small to send or receive UDP packets. To increase the socket buffer size, specify a large buffer size by adding the following parameters to the URL:

url/?rcvbufsz=4000000&sndbufsz=4000000

With these parameters, a transfer to and from a Mac computer is written similar to the following example:

> ascp4 -DD -l 15m --mode send --host 10.13.117.12 --user root --read-threads 1 --write-threads 1 --compression none "udp://233.13.13.2:3002/?rcvbufsz=4000000&sndbufsz=4000000" "udp://233.14.14.2:4002/?rcvbufsz=4000000&sndbufsz=4000000"