Building Carrier-Grade VoIP Observability with Prometheus & AI

Monitoring != Observability. Monitoring: “Server responds to ping.” Observability: “Users hear each other clearly.” If you're running VoIP infrastructure at scale, here's how to avoid the most common mistakes. 1️⃣ Avoid Prometheus Cardinality Explosion If you do this: sip_responses_total{call_id="abc123"} You will crash Prometheus. Instead: sip_responses_total{trunk="us-east", status="503"} Best Practice Aggregate at trunk level Drop call_id labels Use metric_relabel_configs aggressively Use Grafana Loki for per-call debugging. Metrics for trends. Logs for specifics. 2️⃣ Use Recording Rules for Performance Slow dashboards = bad ops. Precompute: job:sip_asr:ratio job:sip_ner:ratio job:rtp_mos:avg Let Prometheus calculate every 15s. Let Grafana just display. Instant dashboards. 3️⃣ Replace Static Alerts with Dynamic Baselines Instead of: alert: ASR < 50% Use: Holt-Winters prediction 4-week historical baselines Time-of-day sensitivity Only alert when deviation is statistically abnormal. A