[Modem Request] Technicolor CGA2121

[sgofferj]

Modem Model

CGA2121

Manufacturer

Technicolor

Modem IP Address

192.168.100.1

Authentication Required

Yes - requires username/password

Authentication Details (if required)

Login type: form
Default username: Admin
Login URL: http://192.168.100.1/logon.html

How are you providing data?

Fallback Mode + Capture HTML (Recommended) - Used built-in capture button

Files Attached

Diagnostic download

config_entry-cable_modem_monitor-01KCV7ZDT43VBB0Q1JPFHXW3D9.json

Modem login and DOCSIS status pages

cga2121.zip

Additional Information

ISP: Telia (Finland)
Docsis Status URL: http://192.168.100.1/st_docsis.html

Checklist

• I have used Fallback Mode + Capture HTML, OR sanitized my files to remove PII
• I have searched my capture file for my WiFi SSID and password to verify they're not present
• I understand this may take time as it requires developing a custom parser
• I'm willing to test the parser once it's developed

[kwschulz]

Thanks for the submission!

I dug into the files and hit a snag - the integration couldn't get past the login page, so it only captured the login form. Your manual browser save shows the DOCSIS status content (24 down / 4 up, SNR, power - all good), but that was after your browser already had a session.

To implement login for this modem, I need to see the actual auth flow:

• POST to /goform/logon with form fields
• Response headers (cookies, redirects)
• How the session stays alive

Every modem does this slightly differently, and the HAR shows us exactly what this one expects.

Can you run our HAR capture tool?

python scripts/capture_modem.py --ip 192.168.100.1

Log in when the browser opens, hit the DOCSIS Status page, wait a few seconds, then close. Attach the .har.gz it generates.

See the HAR Capture Instructions for setup and PII sanitization.

Should have you up and running shortly after that.

[sgofferj]

Wilco. Might take a moment, though.

[sgofferj]

modem_20251220_122559.har.gz

Sanitizing didn't work (couldn't find module utils). However, I use the modem in bridge mode and my Wifi is on a separate access point. I grepped for the modem password and it doesn't seem to be in the HAR archive, so everything should be OK without sanitizing.

[kwschulz]

Parser's up on feature/v3.11.0.

Auth is our best guess from the HAR - the flow looked clean (POST → 302 → sec cookie) but no guarantees until it hits the real thing. If it doesn't work, the parser has verbose debug logging that should show where it's failing.

Heads up: your modem's HTML has the frequency columns commented out, so you'll only get SNR, power, and modulation for the 24 down / 4 up channels.

Let me know how it goes.

[sgofferj]

Any chance you could create a Beta release in HACS? Last time I have manually installed from a GIT repo is a million years ago :D. I try to avoid manual messing around in Home Assistant OS...

Edit: The current DS frequency is at /st_channel_selection.html. I think I have captured that too. If not I can grab it again. Also, Telia is a little bit asshol-ish. They disable a lot of functionality, e.g. the CGA2121 has full SIP client functionality and two phone ports built in but Telia disables it completely, same as the cable TV to IP streaming functionality...

[kwschulz]

On the frequency data: I checked /st_channel_selection.html - unfortunately it's just a provisioning config page with a single 474 MHz starting frequency for cable modem scanning, not per-channel data. The main DOCSIS status page (st_docsis.html) has the frequency columns commented out in the HTML - Telia's firmware literally wraps them in <!-- -->. So the parser is capturing everything that's actually exposed.

On the release: Still wrapping up a few things for v3.11.0 (it includes a breaking change for DOCSIS 3.1 channel naming). Targeting Tuesday - will ping you here once it's on HACS.

The dev cycle is still pretty quick right now with modems getting added regularly, so I haven't set up a proper beta channel yet. Once things stabilize I'll look into it.

[kwschulz]

Quick update - release pushed to next week due to holidays. Happy holidays!