PhonerLite: A Beginner’s Guide to Setup and Use

Troubleshooting PhonerLite: Common Issues and Fixes

1) Registration failures

• Symptoms: “⁄₄₀₁” errors, not listed as registered, no incoming calls.
• Quick fixes: Confirm registrar/proxy host, port (default 5060), username and password; enable “Register” in profile; set correct Realm/Domain.
• Network checks: Allow UDP/TCP/Secure SIP (TLS) in firewall; disable SIP ALG on router; try alternate transport (TCP/TLS) in PhonerLite Options → Network.
• NAT/STUN/UPnP: Enable UPnP on router (preferred) or configure a STUN server in PhonerLite; ensure port forwarding for local signaling port and RTP (local port + 2).

2) No audio or one‑way audio

• Causes: NAT traversal issues, blocked RTP ports, codec mismatch.
• Fixes: Open RTP ports (local port+2 and subsequent even ports) in firewall/router; enable UPnP or use STUN; ensure both endpoints share a common codec (enable G.711/Opus in Codecs); try switching between UDP/TCP for media if available.

3) Calls drop or unstable audio

• Causes: Packet loss, jitter, bandwidth contention, incorrect QoS.
• Fixes: Run speed/jitter tests; prioritize SIP/RTP traffic with QoS on router; reduce concurrent streams or use wired connection; switch to a lower-bandwidth codec (e.g., Opus with lower bitrate).

4) Cannot make calls / app won’t open on call attempts

• Symptoms: Clicking sip: links opens wrong app or shows “How do you want to open this?”
• Fixes (Windows): In PhonerLite Options → URL protocol handler set to “sip”; set PhonerLite as default for SIP protocol in Windows Settings → Apps → Default apps → Choose default apps by protocol → SIP.

5) TLS/certificate and secure connection problems

• Symptoms: TLS connection failures, certificate warnings.
• Fixes: Install/point PhonerLite to proper client certificate (Options → Certificates) if provider requires one; ensure server certificate chain is valid; try plain TCP/UDP if TLS isn’t required.

6) Echo, distortion, or poor call quality

• Causes: Microphone/speaker hardware issues or latency.
• Fixes: Use a quality headset with echo cancellation; enable/disable hardware acceleration in sound device settings; verify sample rates match (e.g., 16 kHz vs 8 kHz) and disable system-level effects.

7) Errors after Windows or router updates

• Symptoms: Previously working accounts stop registering.
• Fixes: Restart PC and router, reapply NAT/port forwarding or UPnP settings, update PhonerLite to latest version, temporarily disable local firewall/AV to test, capture SIP logs for diagnosis.

8) Common UI/config issues

• Profile management: Ensure you edit and save the active profile (Options → Configuration → Profile).
• Local ports: If another app uses the chosen port, let the system assign one or pick an unused port (Options → Network → Local Port).
• Multiple instances: Use Multicast DNS feature carefully—PhonerLite won’t run IPv4 and IPv6 simultaneously.

How to collect useful diagnostics (do this before contacting support)

1. Enable SIP/RTP debug logging in Options → Logbook.
2. Note exact server error codes (401/403/408/486).
3. Capture a short Wireshark/tcpdump trace showing SIP REGISTER/INVITE exchange (redact credentials).
4. Test with another softphone or on another network to isolate PC vs network vs provider.

Quick decision checklist (apply in order)

1. Verify credentials, server address, and Realm.
2. Check PhonerLite local port and codec settings.
3. Open/forward SIP (⁄₅₀₆₁) and RTP ports (local port+2, next evens) or enable UPnP.
4. Disable SIP ALG on router.
5. Test wired connection and headset.
6. Collect logs and contact provider with SIP traces if issue persists.

If you want, I can: generate step‑by‑step settings for your exact provider or analyze a PhonerLite debug log you paste here.