Visualize, configure, and optimize your cellular modem's performance with an intuitive web interface
Note: QManager is the successor to SimpleAdmin, rebuilt from the ground up with a modern tech stack and improved user experience. This branch targets the Quectel RM520N-GL modem running its internal Linux OS (SDXLEMUR, ARMv7l, kernel 5.4.180).
- Live Signal Dashboard — Real-time RSRP, RSRQ, SINR with per-antenna values (4x4 MIMO) and 30-minute historical charts
- Antenna Statistics — Per-port signal breakdown with quality indicators for all 4 antenna ports
- Antenna Alignment — 3-position recording tool that compares composite signal scores to recommend best antenna placement
- Network Events — Automatic detection of band changes, cell handoffs, carrier aggregation changes, and connectivity events
- Latency Monitoring — Real-time ping with 24-hour history, jitter, packet loss, and aggregated views (hourly/12h/daily)
- Traffic Statistics — Live throughput (Mbps) and cumulative data usage
- Band Locking — Select and lock specific LTE/NR bands for optimal performance, with automatic band failover
- Tower Locking — Lock to a specific cell tower by PCI, with automatic failover and scheduled changes
- Frequency Locking — Lock to exact EARFCN/ARFCN channels
- APN Management — Create, edit, delete APN profiles with MNO presets (T-Mobile, AT&T, Verizon, etc.)
- Custom SIM Profiles — Save complete configurations (APN + TTL/HL + optional IMEI) per SIM, with auto-apply on SIM swap
- Connection Scenarios — Save and restore full network configuration snapshots
- Network Priority — Configure preferred network types and selection modes
- Cell Scanner — Active and neighbor cell scanning with signal comparison
- Frequency Calculator — EARFCN/ARFCN to frequency conversion tool
- SMS Center — Send and receive SMS messages directly from the interface
- IMEI Settings — Read, backup, and modify device IMEI, plus IMEI Generator & Validator (Luhn algorithm, TAC presets, imei.info lookup)
- FPLMN Management — View and manage the Forbidden PLMN list
- MBN Configuration — Select and activate modem broadband configuration files
- TTL/HL Settings — IPv4 TTL and IPv6 Hop Limit configuration (iptables-based)
- MTU Configuration — Dynamic MTU application for rmnet interfaces
- IP Passthrough — Direct IP assignment to downstream devices
- Tailscale VPN — One-click install, connect, and manage Tailscale mesh VPN directly from the UI; peer table, health warnings, boot persistence
- Port Firewall — Built-in firewall restricting web UI (80/443) to trusted interfaces; Tailscale-aware, enabled by default
- Connection Watchdog — 4-tier auto-recovery: AT+COPS deregister/reregister -> CFUN toggle -> SIM failover -> full reboot (with token bucket rate limiting)
- Email Alerts — Downtime notifications via Gmail SMTP (msmtp), sent on recovery with duration details
- SMS Alerts — Downtime and recovery notifications delivered over the cellular control channel via
sms_tool; reaches you even while the data link is offline. Registration-guarded retry with dedup collapse, threshold-based suppression of transient blips, bounded failure logging - Low Power Mode — Scheduled CFUN power-down windows via cron
- Software Updates — In-app OTA update checking, download, verification, installation, and rollback
- System Logs — Centralized log viewer with search
- Dark/Light Mode — Full theme support with OKLCH perceptual color system
- Responsive Design — Works on desktop monitors and tablets in the field
- Cookie-Based Auth — Secure session management with rate limiting
- Web Console — Browser-based terminal (ttyd) integrated into the UI with connection status, fullscreen mode, and dark theme
- AT Terminal — Direct AT command interface for advanced users
- Initial Setup Wizard — Guided onboarding for first-time configuration
- A Quectel RM520N-GL modem with RGMII Ethernet connectivity
- Entware installed at
/opt(the installer will bootstrap Entware automatically if not present, but internet access is required) - ADB or SSH access to the modem
Note: QManager is fully independent — it does not require SimpleAdmin or the RGMII Toolkit to be pre-installed. The installer handles everything: Entware bootstrap, lighttpd, user/group creation, and service setup.
ADB or SSH into the modem and run:
curl -fsSL -o /tmp/qmanager-installer.sh \
https://github.com/dr-dolomite/QManager-RM520N/raw/refs/heads/main/qmanager-installer.sh && \
bash /tmp/qmanager-installer.shThe interactive installer fetches the latest release, verifies the SHA-256 checksum, bootstraps Entware (if needed), installs lighttpd, deploys the QManager frontend and backend, configures systemd services, and optionally sets up SSH (dropbear). Bundled dependencies (atcli_smd11, sms_tool, jq, dropbear) are installed automatically. The SSH root password is automatically set to match the web UI password during first-time onboarding. A reboot is triggered after installation.
From v0.1.1+, go to System Settings -> Software Update and use the built-in update flow -- download, verify, and install without SSH. Rollback to the previous version is available if needed.
# SSH into the modem
bash /tmp/qmanager_install/uninstall_rm520n.sh
# To also remove config/profiles/passwords:
bash /tmp/qmanager_install/uninstall_rm520n.sh --purge- Bundled with installer:
atcli_smd11(Rust reimplementation from 1alessandro1/atcli_rust, static ARMv7, AT command transport via/dev/smd11, works across RM502/RM520/RM521/RM551),sms_tool(ARM binary, SMS send/recv/delete with multi-part reassembly),jq(Entware package),dropbear(SSH server) - Downloaded during install:
speedtest(Ookla Speedtest CLI, ARMv7 armhf — downloaded frominstall.speedtest.net) - Installed from Entware:
lighttpd+lighttpd-mod-openssl,sudo,coreutils-timeout - Optional:
msmtp(email alerts) -- can be installed from within the app
| Layer | Technology |
|---|---|
| Frontend | Next.js 16, React 19, TypeScript 5 |
| Styling | Tailwind CSS v4, OKLCH colors, Euclid Circular B + Manrope |
| Components | shadcn/ui (42+ components), Recharts, React Hook Form + Zod |
| Backend | Shell scripts (Bash), CGI endpoints via lighttpd |
| AT Commands | qcmd wrapper with atcli_smd11 on /dev/smd11 (direct, no socat) |
| Init System | systemd (.service units in /lib/systemd/system/) |
| Package Manager | Bun (development), Entware opkg (device) |
Browser --- authFetch() --- lighttpd --- CGI Scripts --- qcmd --- atcli_smd11 --- /dev/smd11 --- Modem
| | |
| Shell Libraries (12) flock serialization
|
reads /tmp/qmanager_status.json
|
qmanager_poller
(tiered polling: 2s/10s/30s)
The frontend is a statically-exported Next.js app served by lighttpd from /usrdata/qmanager/www. The backend is shell scripts running on the modem's internal Linux -- CGI endpoints for API requests and systemd-managed daemons for data collection.
Key Data Flow:
- Poller daemon queries the modem via AT commands every 2-30s (3 tiers) and writes a JSON cache file
- CGI endpoints (63 scripts) read the cache for GET requests, execute AT commands for POST requests
- React hooks (31 custom hooks) poll the CGI layer and provide loading/error/staleness states
- AT transport uses
atcli_smd11on/dev/smd11directly (no socat PTY bridge needed)
Platform Details:
| Concern | RM520N-GL |
|---|---|
| OS | Vanilla Linux (SDXLEMUR, ARMv7l, kernel 5.4.180) |
| Init | systemd |
| Root FS | Read-only by default (remounted RW when needed) |
| Persistent storage | /usrdata/ partition |
| Web server | lighttpd (Entware) |
| Firewall | iptables |
| Config | Files in /etc/qmanager/ |
- Bun (recommended) or Node.js 18+
# Clone the repository
git clone https://github.com/dr-dolomite/qmanager.git
cd qmanager && git checkout dev-rm520
# Install dependencies
bun install
# Start development server (proxies API to modem at 192.168.225.1)
bun run devOpen http://localhost:3000 in your browser.
# Static export to out/
bun run build
# Full package (frontend + backend tarball + checksum)
bun run packageThe package script builds the frontend, bundles it with backend scripts and dependencies into a tarball, and generates a SHA-256 checksum -- ready for distribution via GitHub Releases.
QManager/
├── app/ # Next.js App Router pages (35 routes)
│ ├── dashboard/ # Home — live signal monitoring
│ ├── cellular/ # Cellular info, SMS, profiles, band/tower/freq locking,
│ │ # cell scanner, APN, IMEI, FPLMN, network priority,
│ │ # antenna alignment/statistics
│ ├── local-network/ # IP passthrough, TTL, MTU
│ ├── monitoring/ # Network events, latency, email alerts, watchdog
│ ├── system-settings/ # System config, AT terminal, logs, software updates
│ └── (login, setup, reboot, about-device, support)
├── components/ # React components (~173 files)
│ ├── ui/ # shadcn/ui primitives (42+ components)
│ ├── cellular/ # Cellular management UI
│ ├── dashboard/ # Home dashboard cards
│ ├── local-network/ # Network settings UI
│ ├── monitoring/ # Monitoring & alerts UI
│ └── system-settings/ # System configuration UI
├── hooks/ # Custom React hooks (31 files)
├── types/ # TypeScript interfaces
├── lib/ # Utilities (auth-fetch, earfcn, csv)
├── constants/ # Static data (MNO presets, event labels)
├── scripts/ # Backend shell scripts
│ ├── etc/systemd/system/ # Systemd service units (8)
│ ├── etc/sudoers.d/ # CGI privilege escalation rules
│ ├── etc/qmanager/ # Default config files
│ ├── usr/bin/ # Daemons & utilities (19)
│ ├── usr/lib/qmanager/ # Shared shell libraries (12)
│ ├── www/cgi-bin/ # CGI endpoints (63 scripts)
│ ├── install_rm520n.sh # Device installation script
│ └── uninstall_rm520n.sh # Clean removal script
├── dependencies/ # Bundled ARM binaries and packages
│ ├── atcli_smd11 # ARM binary (AT command transport via /dev/smd11)
│ ├── sms_tool # ARM binary (SMS send/recv/delete)
│ ├── jq.ipk # JSON processor
│ └── dropbear_*.ipk # SSH server
├── docs/ # Documentation
└── build.sh # Package builder (tarball + checksum)
QManager runs 10 systemd services on the modem:
| Service | Purpose |
|---|---|
qmanager-firewall |
Port firewall — restricts 80/443 to trusted interfaces before lighttpd starts |
qmanager-setup |
One-shot boot setup — directories, permissions, config init |
qmanager-poller |
Main poller daemon — tiered AT polling, JSON cache, event detection |
qmanager-ping |
Latency monitor — 5s ping cycle, NDJSON history (24h) |
qmanager-console |
Web console — ttyd on localhost:8080, reverse-proxied by lighttpd |
qmanager-watchcat |
Connection watchdog — 4-tier auto-recovery state machine |
qmanager-ttl |
TTL/HL — applies iptables rules at boot |
qmanager-mtu |
MTU — applies interface MTU settings at boot |
qmanager-imei-check |
IMEI integrity — verifies IMEI backup on boot |
qmanager-tower-failover |
Tower failover — restores lock after cell loss (config-gated) |
Your contribution helps maintain the project and fund continued development, testing on new cellular networks, and hardware costs.
This project is licensed under the MIT License with Commons Clause.
You are free to: use, modify, fork, and share QManager for personal and non-commercial purposes.
You may not: sell QManager, bundle it into a commercial product, or offer it as a paid service -- including forked versions.
If you want to use QManager in a commercial product, OEM device, or reseller offering, commercial licenses are available. Contact DrDolomite directly to discuss terms.
Built with care by DrDolomite