Internet down in an apartment building

mc5

Every 2-3 weeks the internet is down for a few hours. It restarts by itself.

The first technician from Sunrise’s subcontractor ISEN changed some settings and said that if the problem occurs again, they may have to change the house cable amplifier that distributes the internet to several apartments.

A couple of weeks later, when the problem occurred again, a second technician from ISEN came and said that he cannot change the amplifier as all parameters were fine - of course, the amplifier was working when he visited. He also said that there was no record in his ticket of what the first technician recommended.

Two days later after the second technician the amplifier is again down. Cold as dead compared to the one powering other apartments in the building.

I find this a very poor service from Sunrise (or their subcontractor): why would the company prefer spending time and money with (useless) technician visits, frustrating their customers rather than addressing the root cause, i.e. change the faulty amplifier?

Daniele_Sunrise

mc5 I have started an internal request to see if we can see in the network what exactly causes the interruption every 2-3 weeks. At the moment and also historically I don’t see anything that explains your error pattern. However, I do not see 3-4 weeks in the logs. I have asked my colleagues about this.

As soon as I have received feedback, I will report back here.

Greetings
Daniele

Daniele_Sunrise

mc5 As part of the analysis of the connection interruptions you reported, we checked the signal values of your connection and those of the directly adjacent neighborhood. No anomalies or restrictions could be identified that would clearly explain the interruptions.

In the last two weeks, several short interruptions can be seen in the history of your modem, but these cannot be clearly traced in terms of signal technology. No comparable interruptions were detected in the immediately neighboring connections during the same period.

According to the available technician report, the house amplifier (HVA) was correctly reset as it was previously set too high. The signal values are currently stable and unremarkable. As a problem with the house amplifier would generally affect several households, we do not currently assume that this is the cause of the interruptions.

In your modem logs, the entries “HW or Power-On Reset” and “SYNC Timing Synchronization failure - Failed to acquire FEC framing” as well as “DOCSIS scan without locking” were registered. These indicate a hard restart of the modem and short-term downstream synchronization problems. Possible causes include local or sporadic interference (which is not necessarily visible in the static signal values). No such entries were detected for the neighboring connections.

Our recommendations for further localization:
1. Please ensure that the modem is connected directly to a fixed wall socket (no switchable power strips) and use the original power supply unit if possible.
2. Check the house wiring, especially the coaxial cable between the modem and the antenna socket and the plug connections.
3. If the interruptions continue to occur, we recommend replacing the modem and power supply unit. Please contact us again here.

Greetings
Daniele

mc5

Many thanks for looking into the matter and providing the details.

Each time the interruption occurred, it affected at least three households in the same building and the technicians were informed about that.

After the latest breakdown which latest almost eight hours we had the house amplifier replaced. Other neighbors, connected to a different amplifier, explained that they had the same issue and solution was also to replace the amplifier. I’m writing this as a REX for Sunrise and, maybe, other customers: the data that you can read remotely may not always lead to the root cause of the problem.

Best regards,

Daniele_Sunrise

mc5 We have completed the evaluation of a few days of modem monitoring.

Here is the feedback from the analysis:
"The current modem logs no longer show any T3 or T4 timeouts, which indicates stable unicast maintenance and a currently inconspicuous return channel.

The entry “US profile assignment change” (DOCSIS 3.1 OFDMA) is not a critical error in itself, but describes a dynamic adjustment of the upstream profile by the CMTS, as is usual in the event of slight or temporary fluctuations in the signal conditions.

The previously registered logs (“HW or Power-On Reset”, “SYNC Timing Synchronization failure”, “DOCSIS scan without locking”) indicate earlier, short-term downstream synchronization problems or a restart of the modem, presumably caused by sporadic or local interference that is not necessarily visible in static signal values. There are currently no indications of a persistent or acute fault from the log situation."

If the errors occur again, please check the following:
- Check the power supply (direct wall socket, correct power supply unit, no switchable power strips)
- Check the house cabling (coax patch cable, antenna socket, plug)
- If interruptions continue to occur: Modem replacement including power supply unit

Greetings
Daniele