A4 is a FASP transfer program similar to the standard Ascp, but that hasbeen optimized for sendingvery large sets of individual files and can support UDP multicast. Both Ascp4 and ascp are automatically installed with Aspera Enterprise Server, Point-to-Point, and Desktop Client applications. The architecture transfers one million (1MM) files per minute for even the smallest file sizes (e.g. <10KB) and achieves > 5Gbps transfer rates for global RTT and packet loss conditions (200ms / 2%). See A4's Performance Benchmarks.

Features and Benefits

  • Extremely fast small file transfers to cloud storage 10-100X faster than S3 HTTP multipart over WAN (250-500 files transferred per second for throughputs greater than 500 Mbps for files of average size <=10 KB).
  • File metadata is sent over the FASP transport channel, alongside the data, eliminating the per-file overhead of sending this metadata on TCP.
  • Additionally read/write I/O is highly parallelized and chunk sizes are configurable, allowing for maximum per file open rates for even the smallest files.
  • Pipelined file I/O mechanism feeds incoming chunks through compression, encryption and transfer as they are coming in from disk.
  • The number of parallel I/O threads is configurable.
  • Integrated in Aspera Console for transfer initiation, control and reporting.
  • Supports resumable transfers
  • Configurable overwrite policies and skip saving of existing files
  • Direct to cloud storage transfer support