The deployment model

flowchart TB subgraph Host1["ePDG Server"] EPDG["fast-epdg
(VoWiFi gateway)"] PLUGIN["/metrics endpoint
:9817"] EPDG -.-> PLUGIN end subgraph Host2["Monitoring server"] PROM["Prometheus"] GRAF["Grafana"] AM["Alertmanager"] SNMPTRAP["SNMP Trap Sender
(webhook gateway)"] PROM --> GRAF PROM --> AM AM --> SNMPTRAP end subgraph Host3["External systems"] NMS["Операторская NMS
(HP OpenView /
NetAct / Tivoli)"] CHAT["ChatOps
(Telegram / PagerDuty)"] end PLUGIN -->|HTTP :9817/metrics| PROM SNMPTRAP -->|UDP 162| NMS AM -->|Webhook| CHAT

Deployment characteristics

Parameter	Value
Metrics footprint	Integrated (~2 MB memory overhead)
External dependencies	The self-contained `fast-epdg` package (rpm)
Management	`fast-epdg.service` systemd
Configuration	The `monitoring` section in `fast-epdg.conf`
Update	Updating the configuration without interrupting operations
OS	Linux (RHEL/CentOS 8+, Ubuntu 22.04+)
Port	9817 TCP (listening on 0.0.0.0, configurable)
Deployment time	< 5 minutes (enable the plugin in the config file + restart)

Accommodation options

On-premise — the plugin runs in the fast-epdg address space, zero resource consumption
Co-located Prometheus — Prometheus collects metrics from an application running on the same host
Centralized — a single Prometheus collects from all ePDG nodes