From 1ad460cee61a2a5724f20d8ca834107f4bf4f6f3 Mon Sep 17 00:00:00 2001
From: Joachim Bauch <bauch@struktur.de>
Date: Thu, 13 Nov 2025 14:39:57 +0100
Subject: [PATCH] Add metrics for media RTT / jitter.

---
 docs/prometheus-metrics.md  |  2 ++
 mcu_janus_events_handler.go |  9 +++++++++
 mcu_stats_prometheus.go     | 16 ++++++++++++++++
 3 files changed, 27 insertions(+)

diff --git a/docs/prometheus-metrics.md b/docs/prometheus-metrics.md
index 6784592..ac4a3c2 100644
--- a/docs/prometheus-metrics.md
+++ b/docs/prometheus-metrics.md
@@ -66,3 +66,5 @@ The following metrics are available:
 | `signaling_mcu_ice_state_total`                   | Counter   | 2.0.5     | Total number of ICE connection states                                     | `state`                           |
 | `signaling_mcu_dtls_state_total`                  | Counter   | 2.0.5     | Total number of DTLS connection states                                    | `state`                           |
 | `signaling_mcu_slow_link_total`                   | Counter   | 2.0.5     | Total number of slow link events                                          | `media`, `direction`              |
+| `signaling_mcu_media_rtt`                         | Histogram | 2.0.5     | The roundtrip time of WebRTC media in milliseconds                        | `media`                           |
+| `signaling_mcu_media_jitter`                      | Histogram | 2.0.5     | The jitter of WebRTC media in milliseconds                                | `media`, `origin`                 |
diff --git a/mcu_janus_events_handler.go b/mcu_janus_events_handler.go
index b1bae25..3467102 100644
--- a/mcu_janus_events_handler.go
+++ b/mcu_janus_events_handler.go
@@ -757,6 +757,15 @@ func (h *JanusEventsHandler) processEvent(event JanusEvent) {
 		}
 		statsJanusSlowLinkTotal.WithLabelValues(evt.Media, direction).Inc()
 	case *JanusEventMediaStats:
+		if rtt := evt.RTT; rtt > 0 {
+			statsJanusMediaRTT.WithLabelValues(evt.Media).Observe(float64(rtt))
+		}
+		if jitter := evt.JitterLocal; jitter > 0 {
+			statsJanusMediaJitter.WithLabelValues(evt.Media, "local").Observe(float64(jitter))
+		}
+		if jitter := evt.JitterRemote; jitter > 0 {
+			statsJanusMediaJitter.WithLabelValues(evt.Media, "remote").Observe(float64(jitter))
+		}
 		h.mcu.UpdateBandwidth(event.HandleId, evt.Media, api.BandwidthFromBytes(uint64(evt.BytesSentLastSec)), api.BandwidthFromBytes(uint64(evt.BytesReceivedLastSec)))
 	}
 }
diff --git a/mcu_stats_prometheus.go b/mcu_stats_prometheus.go
index 239249a..a13ef1b 100644
--- a/mcu_stats_prometheus.go
+++ b/mcu_stats_prometheus.go
@@ -128,6 +128,20 @@ var (
 		Name:      "slow_link_total",
 		Help:      "Total number of slow link events",
 	}, []string{"media", "direction"})
+	statsJanusMediaRTT = prometheus.NewHistogramVec(prometheus.HistogramOpts{
+		Namespace: "signaling",
+		Subsystem: "mcu",
+		Name:      "media_rtt",
+		Help:      "The roundtrip time of WebRTC media in milliseconds",
+		Buckets:   prometheus.ExponentialBucketsRange(1, 10000, 25),
+	}, []string{"media"})
+	statsJanusMediaJitter = prometheus.NewHistogramVec(prometheus.HistogramOpts{
+		Namespace: "signaling",
+		Subsystem: "mcu",
+		Name:      "media_jitter",
+		Help:      "The jitter of WebRTC media in milliseconds",
+		Buckets:   prometheus.ExponentialBucketsRange(1, 2000, 20),
+	}, []string{"media", "origin"})
 
 	janusMcuStats = []prometheus.Collector{
 		statsJanusBandwidthCurrent,
@@ -137,6 +151,8 @@ var (
 		statsJanusICEStateTotal,
 		statsJanusDTLSStateTotal,
 		statsJanusSlowLinkTotal,
+		statsJanusMediaRTT,
+		statsJanusMediaJitter,
 	}
 
 	statsConnectedProxyBackendsCurrent = prometheus.NewGaugeVec(prometheus.GaugeOpts{