Alexa RTSP Connection Issue – Camera Never Connects After Monocle Gateway Setup

willh2o

Hello all,

I’m troubleshooting an issue with Monocle Gateway where Alexa devices are unable to successfully stream from my RTSP camera. I’m hoping someone here might have additional ideas.

Current behavior:

Monocle Gateway starts properly.

Alexa devices send the initial connection request (I can see RTSP CLIENT SOCKET CONNECTED in the logs).

However, the expected log entry showing the camera connecting never happens.

Eventually, Alexa devices time out and display an error (“camera not responding”).

Troubleshooting steps and confirmations:

The Monocle Gateway logs point to the troubleshooting page https://monoclecam.com/monocle-gateway-troubleshooting.

I have carefully followed and completed all the recommended steps there (at least I think I have).

DNS is correctly resolving the mproxy.io URL to the internal IP (tested with nslookup and verified).

Firewall (UFW) rules are open for TCP 443 and RTSP-related ports.

A direct TLS connection to the Monocle Gateway using OpenSSL succeeds, and the Monocle certificate chain is presented.

No unusual TLS errors beyond expected self-signed chain notices.

Monocle Gateway is properly listening on 443 and not blocked.

The original camera RTSP URL (rtsp://192.168.42.1:7447/…) works fine if directly opened inside the VLAN.

Pi-hole is running on the same Ubuntu server as Monocle Gateway (expected and working properly).

Additional context:

I recently updated the Unifi Network app (running on a UDM-SE).

I cannot fully rule out that the issue started after this update, but it does not seem to correlate exactly with when the problem appeared.

This setup has worked very happily for years without issue.

Something recently changed, but at this point, I am not sure what.

Current situation:

Alexa and Monocle Gateway are communicating at the first step, but the camera never initiates the expected inbound RTSP session to the Gateway.

No new log entries indicating the camera connection, only Alexa’s initial socket connection followed by a timeout.

pr 26 10:34:19 will-ubuntu monocle-gateway[8586]: -------------------------------------------------
Apr 26 10:34:19 will-ubuntu monocle-gateway[8586]: INITIALIZE RTSP STREAM:  Front Door
Apr 26 10:34:19 will-ubuntu monocle-gateway[8586]: -------------------------------------------------
Apr 26 10:34:19 will-ubuntu monocle-gateway[8586]:  - NAME          : Front Door
Apr 26 10:34:19 will-ubuntu monocle-gateway[8586]:  - CAMERA.MFG    : Ubiquiti
Apr 26 10:34:19 will-ubuntu monocle-gateway[8586]:  - CAMERA.MODEL  : G4 Doorbell Pro
Apr 26 10:34:19 will-ubuntu monocle-gateway[8586]:  - CAMERA.LABEL  : PRIMARY
Apr 26 10:34:19 will-ubuntu monocle-gateway[8586]:  - RTSP.URL      : rtsp://192.168.42.1:7447/sG5I6BCLCQhB1fAC
Apr 26 10:34:19 will-ubuntu monocle-gateway[8586]:  - STREAM.ID     : STREAM:be9d6e8b-2f12-40ca-9679-32bd91a7a708
Apr 26 10:34:19 will-ubuntu monocle-gateway[8586]:  - SESSION.ID    : 68618f72-4881-4611-a05a-d0b81ee4b953
Apr 26 10:34:19 will-ubuntu monocle-gateway[8586]:  - LAST.MODIFIED : Wed Aug 24 2022 16:51:49 GMT-0500 (Central Daylight Time)
Apr 26 10:34:19 will-ubuntu monocle-gateway[8586]:  - TAGS          : @fixaudio,@tunnel
Apr 26 10:34:19 will-ubuntu monocle-gateway[8586]: -------------------------------------------------
Apr 26 10:34:19 will-ubuntu monocle-gateway[8586]:  ATTENTION -> Next you should see log statements showing your camera
Apr 26 10:34:19 will-ubuntu monocle-gateway[8586]:               establishing an inbound connection to this gateway instance via:
Apr 26 10:34:19 will-ubuntu monocle-gateway[8586]:  -> DNS URL: rtsp://5fd9e65d-6aff-4e24-8661-b8d7a1c657c6.mproxy.io:443/STREAM:be9d6e8b-2f12-40ca-9679-32bd91a7a708
Apr 26 10:34:19 will-ubuntu monocle-gateway[8586]:  -> This DNS host address should resolve to: 192.168.42.10:443 on your network.
Apr 26 10:34:19 will-ubuntu monocle-gateway[8586]:  NOTE: If you don't receive any inbound connection log statements,
Apr 26 10:34:19 will-ubuntu monocle-gateway[8586]:        please see: https://monoclecam.com/monocle-gateway-troubleshooting

Environment:

Ubuntu 22.04 server

Monocle Gateway v0.0.6
monocle.token verified and working

Local DNS handled by Pi-hole

Unifi UDM-SE router managing the VLAN where all devices are located

Question:

Are there any additional troubleshooting steps that could explain why the camera would not open an inbound session back to the Monocle Gateway?

Thanks in advance for any suggestions or ideas you might have!

— Will

Joe

Will, is this a new setup or have you had connectivity in the past? I lost connectivity to my Alexa devices back in January. This has happened in the past and was always a server/certificate error on Monocle’s system. This last time, the problem persisted for weeks and there was never any response from Monocle regarding the problem. I gave up & replaced the Monocle functionality by setting up a Scrypted server within Home Assistant, and it provides the same connectivity to Alexa that I had before. You don’t have to have Home Assistant to set up a Scrypted server. It will run on various OS.

willh2o

@Joe Thanks so much for posting this. Monocle had been rock solid for me for the past two years, so this recent issue really threw me off.
I checked out Scrypted after seeing your post, gave it a try, and it’s doing exactly what I needed from MonocleCam.
Looks like I’ll be moving over to Scrypted for now too. That said, I’ll definitely keep checking back here — I’ve always liked the Monocle solution and would love to come back if things pick back up.
Really appreciate you sharing your experience — it made all the difference getting my setup back online!