New T3/T4 errors appeared again after months of stability

[j_p_]

Hi Ziggo,

After several months of stability, I noticed new critical T3 and T4 timeout events in my modem log today (04-11-2025). The messages seem a bit different from the ones I saw before, so I’m not sure if they indicate the same type of issue or something else.

In the past, I experienced frequent disconnections caused by T3/T4 errors. Two technicians visited and replaced the indoor coaxial cable twice. After the second replacement, the connection was finally stable for quite a while.

Here’s my previous topic for reference:
https://community.vodafoneziggo.nl/t5/Archief/Frequent-disconnects-with-T3-T4-timeouts-issue-has-wor...

Could someone please have a look at the recent log entries and let me know if these new errors suggest the same upstream/downstream issue as before, or if this is something different? Although the messages look a bit different this time (for example more detailed DOCSIS 3.1 sync/timing errors), they seem to occur in a similar pattern as the earlier T3/T4 outages. I’m not sure whether this indicates that the original line issue is still present in the background.

Based on these logs, would a TDR test still be advisable, or should I wait and only schedule it again if the problem becomes frequent?

Thanks in advance!

[tobiastheebe]

The downstream (DOCSIS) signal appears to drop out since the T3 + T4 timeouts are accompanied by SYNC timing failure. Some of these events may be ingnored because the modem rebooted at 28-8 15:02 (unknown reason) and 4-11 5:44 (SNMP/docsDevResetNow).

I still recommend a TDR test between AOP and EV. A moderator can schedule a new technician appointment.

[j_p_]

Thank you so much again for the explanation and recommendation!

[j_p_]

To moderator: could you please arrange a technician visit for a proper TDR test between the AOP and EV, as Tobias suggested?
It would be great if the technician assigned is familiar with TDR measurements. I’d like to avoid another visit limited to indoor inspection, since the indoor cable has already been replaced twice.

[Ryan]

Yes, that we can do!
We've send you via the Outlook mail the option to schedule a technician. Then you can schedule one that fits your own schedule. Will you keep us updated? 🙂

[j_p_]

Thanks for your help. I have scheduled a technician "Dit is de afspraak die gemaakt is: Dinsdag 11 november tussen 13.00 - 16.00".

[j_p_]

I added a note in my appointment requesting a TDR test, but I’m not fully sure whether this remark will always be visible to the technician who gets assigned. Could you please help ensure that a technician familiar with the TDR procedure is scheduled?

One important thing is that the issue is intermittent, so it does not always show up during the visit. Even if the connection looks stable at that moment, the underlying problem is still there, which is why the TDR test is needed.
And just to avoid any confusion during the visit, please note that my house number includes an additional letter as a suffix. I suppose one of the past technicians missed it, so I wanted to mention it in advance.

Thanks a lot for your help!

[Ryan]

All is there in the note. the planning is used to determine which mechanic is best suited to carry out the work for this adres.