VDSL modem losing synchronization and restarting during training without clear cause.
VDSL modem losing synchronization and restarting during training without clear cause.
Hello! It's been nearly two years since you started noticing problems with your VDSL 250/40 MBit connection from Telekom Germany. You're trying to figure out what might be causing the intermittent disconnections—your modem reboots frequently, sometimes multiple times a day or even every few days, and it usually happens at random times. You've tested several modems, including different models from Zyxel, Draytek, and Speedport, but none seem to resolve the issue. You've also swapped cables, updated your setup, and even tried a lower-speed modem, yet the problem persists.
You replaced the internal box and changed the cable paths, but the disconnections continue. The ISP has not offered further assistance. Since you work from home, this unreliability is definitely affecting your workflow. I understand how frustrating this must be. If you could share more details about your current setup or any recent changes, it might help narrow things down. Any suggestions would be really appreciated!
what's your modem? the device that connects directly to your internet. yes, i'm using an unsupported [redacted] modem router thingy—no other modems or routers, just to avoid any hassle. my speed is capped at 100mbit even though the modem supports more, and there are no problems. in short, if you have a compatible modem (prove it), the ISP must assist you or you can cancel your contract within about three weeks.
T-Com operates under Deutsche Telekom, Hrvatski Telekom and T-Mobile. It's unlikely you'll resolve this issue on your own. Consider moving to a different wired option such as fiber or cable, and eventually transition to 5G (not the misleading 4G LTE version).
The majority of these lines come from Telekom, meaning even if you change providers, you’ll likely remain tied to the same content (unless you opt for wireless, which still has problems like weak signals and slow speeds). I’d probably switch again if they don’t assist properly, which is rare in my experience.
Globally, T-com focuses solely on having "a service," not on ensuring it functions correctly. They treat problems like blackouts or connection drops as mere inconveniences, assuming the line will resolve them automatically. However, when issues such as CRC/FEC/HEC/SES errors or packet loss occur, they won’t intervene since they believe the line itself is reliable.
Well, apparently it happens sometimes, so it's more of an edge case. The CRC errors are normal too, and there are no actual disconnections. It’s usually fine, especially with certain connections, unless you have a lot of them. This shouldn’t cause any issues. What seems to be happening is that Telekom might be intentionally resetting the OPS line for some reason. Complaining can help, but it won’t always work. It really depends on how determined the person responsible is. I’d suggest setting a deadline—like fixing it within three weeks—or canceling the contract if they don’t act. Also, using only a Telekom-approved modem would make things much simpler for them.