Problem
SRT packet-loss recovery exceeds the available latency budget, producing visible freezes during transient network loss.
Solution
Root Cause / Diagnostic:
SRT uses Automatic Repeat reQuest (ARQ) over UDP to retransmit lost packets within a user-defined latency buffer window. If the configured SRT latency is lower than 2.5 to 4 times the Round Trip Time (RTT), retransmitted packets cannot arrive before playback deadlines expire. When this threshold is breached, unrecovered packets are discarded, producing visible macroblocking and frozen video frames.
Actionable Fix:
1. Increase SRT caller latency to at least 3 to 4 times your measured RTT to the ingest server (e.g., set latency to 800ms-1200ms if ping exceeds 200ms).
2. Configure SRT overhead bandwidth percentage (e.g., oheadbw=25) to allocate adequate pipe capacity for retransmit packets during burst loss.
3. Test packet-loss resilience using an SRT test endpoint with simulated 5% packet loss to verify smooth, uninterrupted playback.
Pro Tip:
Trading 500ms of stream latency for bulletproof SRT packet recovery protects overall watch time, preventing high-intent viewers and paying members from dropping off during minor network blips.
SRT uses Automatic Repeat reQuest (ARQ) over UDP to retransmit lost packets within a user-defined latency buffer window. If the configured SRT latency is lower than 2.5 to 4 times the Round Trip Time (RTT), retransmitted packets cannot arrive before playback deadlines expire. When this threshold is breached, unrecovered packets are discarded, producing visible macroblocking and frozen video frames.
Actionable Fix:
1. Increase SRT caller latency to at least 3 to 4 times your measured RTT to the ingest server (e.g., set latency to 800ms-1200ms if ping exceeds 200ms).
2. Configure SRT overhead bandwidth percentage (e.g., oheadbw=25) to allocate adequate pipe capacity for retransmit packets during burst loss.
3. Test packet-loss resilience using an SRT test endpoint with simulated 5% packet loss to verify smooth, uninterrupted playback.
Pro Tip:
Trading 500ms of stream latency for bulletproof SRT packet recovery protects overall watch time, preventing high-intent viewers and paying members from dropping off during minor network blips.