Bidirectional WebSockets vs Server-Sent Events for Real-Time Telemetry

Author: Real-Time Communications Team

#WebSockets#SSE#Real-Time#Low-Latency

1. Context & Problem Statement

TradingMaster.app and AI-Reception.ist require high-frequency bi-directional data flow: TradingMaster requires sub-millisecond client heartbeat pings and order execution acknowledgments; AI-Reception.ist requires full-duplex streaming audio frames.

2. Decision

We standardized on Bidirectional WebSockets over TLS 1.3 for all live telemetry and audio streaming, rather than unidirectional Server-Sent Events (SSE). We implemented binary ArrayBuffer protocols with compression for market feeds and Opus streaming for voice.

3. Consequences & Trade-Offs

Positive Outcomes

True full-duplex communication with negligible per-message framing overhead (2–10 bytes)

Support for binary audio packets (Opus) and binary market order books without Base64 encoding tax

Negative / Trade-Offs

Requires custom client-side reconnection logic and exponential backoff retry handling

Mitigation Strategies

Built an enterprise-grade resilient WebSocket client wrapper with automatic heartbeat and offline queuing

Standards & References

https://datatracker.ietf.org/doc/html/rfc6455

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