ascp4: Transferring from the Command Line with Ascp 4 Ascp 4 is a command-line FASP file transfer program that is similar to Ascp, but has different strengths and capabilities. Introduction to Ascp 4 Ascp 4 is optimized for sending extremely large sets of files (thousands and more small files in a single session). Ascp 4 Command Reference Supported environment variables, the general syntax, and command options for ascp4 are described in the following sections. ascp4 exits with a 0 on success or a 1 on error. The error code is logged in the ascp4 log file. Ascp 4 Transfers with Object Storage Files that are transferred with object storage are sent in chunks through the Aspera Trapd service. By default, ascp4 uses 64 KB chunks and Trapd uses 1 MB chunks; this mismatch in chunk size can cause ascp4 transfers to fail. Ascp 4 Examples Built-in I/O Providers Input/Output providers are library modules that abstract I/O scheme in Ascp 4 architecture. Ascp 4 has the following built-in I/O providers: Data Streaming Command Syntax The ascp4 that is installed with HST Server can be used for data streaming as well as regular file transfers. The command line is similar to a regular ascp4 file transfer, but the source and destination are URI paths. The license prohibits video streaming. A separate product, IBM Aspera Streaming for Video, is available for video streaming. For more information, see the IBM Aspera Streaming for Video User Guide. Ascp 4 Data Streaming Examples Use the following examples as a guide for creating your own streaming transfers with Ascp 4. Configuring macOS Server for Multicast Streams If you are sending or receiving multicast streams from a macOS server, multicast fails if the receiving or sending interface is not the macOS default interface. If no default gateway is defined on a macOS server, the default interface is en0. To use a different interface than the default, change the default interface for your server Troubleshooting Stream Transfers Using Ascp 4 from the GUI By default, transfers that are started in the GUI use Ascp and Ascp 4 transfers can be run only from the command line. You can make transfers that are started in the GUI use Ascp 4 by renaming the executables.