Relay Infrastructure at WhatsApp Scale

on YouTube ↗16m

" summary

WhatsApp relays more than a billion calls daily using a global fabric of thousands of PoPs and per‑region clusters with hundreds of relay containers, automatic scaling and prioritization that favors ongoing and one‑on‑one calls during spikes. The relays cache and retransmit dropped packets, perform bandwidth estimation to prevent congestion, use selective forwarding and video simulcast to conserve battery and serve asymmetric networks, and persist minimal metadata in a state server so connections survive container failures and upgrades.

AI-written summary · about

" chapters (6)

1. 0:00Start
2. 3:05What is a relay?
3. 7:03Problem of too many streams in a group call Resource Usage
4. 9:18Problem of asymmetric networks
5. 9:49Solving for asymmetric networks
6. 13:27Throttling to prevent catastrophic failure

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