How to Troubleshoot Flussonic Disruptions: Optimizing Network Settings for Smooth Transcoded HLS Output

Introduction:

Encountering disruptions in transcoded HLS output with Flussonic Media Server can be a perplexing issue, especially when hardware upgrades fail to resolve the problem. In this blog post, we’ll explore a case where a client faced image degradation and the steps taken to rectify it. The information shared here aims not only to assist the client but also to provide valuable insights for others facing similar challenges.

The Challenge:

The client reported disruptions on all transcoded HLS streams, both live and from the archive. Despite upgrading from an NVidia Quadro P6000 to a Tesla A16 and utilizing dual CPU encoder channels with a modest 30% CPU load, the issue persisted. The quest for a solution led to the discovery of an unconventional culprit – network card settings.

Discovery:

Through meticulous checks and experiments, we found that adjusting the size of RX/TX buffers to 4096 resolved the disruptions. This adjustment was crucial for obtaining high-quality output from the Flussonic transcoder.

Optimizing Network Buffers:

Network interfaces, especially in high-performance servers, utilize transmit (TX) and receive (RX) buffer rings for efficient packet transfer. Regular desktop NICs typically default to 256 or 512 bytes, while performance-grade NICs can handle up to 4096 or 8192 bytes.

Implementation Steps:

Install ethtool if not already installed: apt-get install ethtool

Check current buffer settings: ethtool -g eth0

Adjust buffers to 4096 bytes: ethtool -G <int name> rx 4096 tx 4096 or ethtool --set-ring <int name> rx 4096 tx 4096

Verify the changes: ethtool -g eth0

Conclusion:

For users aiming to attain excellent results from Flussonic’s transcoder, optimizing network buffer settings is crucial. The client’s solution of increasing RX/TX buffer size to 4096 serves as a practical recommendation. While Flussonic may not automate this setting, considering it as a manual adjustment can significantly enhance the streaming experience. By following these steps, users can potentially overcome disruptions and ensure a seamless, high-quality streaming performance with Flussonic Media Server.