TCP and UDP performance tuning

Edit online

The optimal settings of the tunable communications parameters vary with the type of LAN, as well as with the communications-I/O characteristics of the predominant system and application programs. This section describes the global principles of communications tuning for AIX®.

Use the following outline for verifying and tuning a network installation and workload:

  • Ensure adapters are placed in the proper slots.
  • Ensure system firmware is at the proper release level
  • Ensure adapter and network switches are in proper speed and duplex mode
  • Ensure correct MTU size has been selected
  • Adjust AIX tunables for network type, speed, and protocol
  • Other considerations:
    • Adapter offload options
      • TCP checksum offload
      • TCP large send or re-segmentation
    • Interrupt coalescing
    • Input threads (Dog threads)