Uncorrectables, modem reboots

[stretch47]

Several times per week, my internet service stops working. The network status page shows uncorrectable errors. Please see attached screen shots. Is there a way to get a more stable connection?

[Bert]

To evaluate your incoming and outgoing signal, can you post here from your modem the full pages of downstream and upstream values with a screenshot and last days Network history?

Where can I find the up and downstream values of my modem?
https://community.ziggo.nl/t5/Tips-van-Ziggo/Waar-vind-ik-de-up-en-downstreamwaarden-van-mijn-modem/...

Can you place a photo here of the first place where Ziggo enters your house with any splitters and amplifiers and modem in the photo?

[tobiastheebe]

-

[stretch47]

Here you go. See attached screenshots and photos.  I put the network log in the spoiler section below.

Lees meer

Network Log

Time Priority Description

Thu 01/01/1970 01:01:33	3	No Ranging Response received - T3 time-out;CM-MAC=ac:f8:cc:db:a4:4c;CMTS-MAC=00:01:5c:b3:b6:5d;CM-QOS=1.1;CM-VER=3.1;
Thu 01/01/1970 01:01:57	3	No Maintenance Broadcasts for Ranging opportunities received - T2 time-out;CM-MAC=ac:f8:cc:db:a4:4c;CMTS-MAC=00:01:5c:b3:b6:5d;CM-QOS=1.1;CM-VER=3.1;
Thu 01/01/1970 01:01:58	3	No Ranging Response received - T3 time-out;CM-MAC=ac:f8:cc:db:a4:4c;CMTS-MAC=00:01:5c:b3:b6:5d;CM-QOS=1.1;CM-VER=3.1;
Thu 01/01/1970 01:03:43	5	B-INIT-RNG Failure - Retries exceeded;CM-MAC=ac:f8:cc:db:a4:4c;CMTS-MAC=00:01:5c:b3:b6:5d;CM-QOS=1.1;CM-VER=3.1;
Thu 01/01/1970 01:03:44	3	No Ranging Response received - T3 time-out;CM-MAC=ac:f8:cc:db:a4:4c;CMTS-MAC=00:01:5c:b3:b6:5d;CM-QOS=1.1;CM-VER=3.1;
Thu 01/01/1970 01:05:12	5	B-INIT-RNG Failure - Retries exceeded;CM-MAC=ac:f8:cc:db:a4:4c;CMTS-MAC=00:01:5c:b3:b6:5d;CM-QOS=1.1;CM-VER=3.1;
Thu 01/01/1970 01:05:14	3	No Ranging Response received - T3 time-out;CM-MAC=ac:f8:cc:db:a4:4c;CMTS-MAC=00:01:5c:b3:b6:5d;CM-QOS=1.1;CM-VER=3.1;
Thu 01/01/1970 01:06:23	5	B-INIT-RNG Failure - Retries exceeded;CM-MAC=ac:f8:cc:db:a4:4c;CMTS-MAC=00:01:5c:b3:b6:5d;CM-QOS=1.1;CM-VER=3.1;
Thu 01/01/1970 01:06:24	3	No Ranging Response received - T3 time-out;CM-MAC=ac:f8:cc:db:a4:4c;CMTS-MAC=00:01:5c:b3:b6:5d;CM-QOS=1.1;CM-VER=3.1;
Thu 01/01/1970 01:07:57	5	B-INIT-RNG Failure - Retries exceeded;CM-MAC=ac:f8:cc:db:a4:4c;CMTS-MAC=00:01:5c:b3:b6:5d;CM-QOS=1.1;CM-VER=3.1;
Thu 01/01/1970 01:07:59	3	No Ranging Response received - T3 time-out;CM-MAC=ac:f8:cc:db:a4:4c;CMTS-MAC=00:01:5c:b3:b6:5d;CM-QOS=1.1;CM-VER=3.1;
Thu 13/10/2022 14:22:17	5	MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1;CM-MAC=ac:f8:cc:db:a4:4c;CMTS-MAC=00:01:5c:b3:b6:5d;CM-QOS=1.1;CM-VER=3.1;
Thu 13/10/2022 16:04:23	6	CM-STATUS message sent. Event Type Code: 24; Chan ID: 33; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 3.;CM-MAC=ac:f8:cc:db:a4:4c;CMTS-MAC=00:01:5c:b3:b6:5d;CM-QOS=1.1;CM-VER=3.1;
Fri 14/10/2022 02:24:54	6	US profile assignment change. US Chan ID: 27; Previous Profile: 12; New Profile: 11.;CM-MAC=ac:f8:cc:db:a4:4c;CMTS-MAC=00:01:5c:b3:b6:5d;CM-QOS=1.1;CM-VER=3.1;
Fri 14/10/2022 02:37:22	6	CM-STATUS message sent. Event Type Code: 24; Chan ID: 33; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 2.;CM-MAC=ac:f8:cc:db:a4:4c;CMTS-MAC=00:01:5c:b3:b6:5d;CM-QOS=1.1;CM-VER=3.1;
Fri 14/10/2022 04:16:16	6	US profile assignment change. US Chan ID: 27; Previous Profile: 11; New Profile: 12.;CM-MAC=ac:f8:cc:db:a4:4c;CMTS-MAC=00:01:5c:b3:b6:5d;CM-QOS=1.1;CM-VER=3.1;
Fri 14/10/2022 06:59:35	6	CM-STATUS message sent. Event Type Code: 24; Chan ID: 33; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 2.;CM-MAC=ac:f8:cc:db:a4:4c;CMTS-MAC=00:01:5c:b3:b6:5d;CM-QOS=1.1;CM-VER=3.1;
Fri 14/10/2022 07:26:59	6	US profile assignment change. US Chan ID: 27; Previous Profile: 11; New Profile: 12.;CM-MAC=ac:f8:cc:db:a4:4c;CMTS-MAC=00:01:5c:b3:b6:5d;CM-QOS=1.1;CM-VER=3.1;
Fri 14/10/2022 09:59:48	6	CM-STATUS message sent. Event Type Code: 24; Chan ID: 33; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 1.;CM-MAC=ac:f8:cc:db:a4:4c;CMTS-MAC=00:01:5c:b3:b6:5d;CM-QOS=1.1;CM-VER=3.1;
Fri 14/10/2022 10:57:03	6	US profile assignment change. US Chan ID: 27; Previous Profile: 11; New Profile: 12.;CM-MAC=ac:f8:cc:db:a4:4c;CMTS-MAC=00:01:5c:b3:b6:5d;CM-QOS=1.1;CM-VER=3.1;
Fri 14/10/2022 12:54:06	6	CM-STATUS message sent. Event Type Code: 24; Chan ID: 33; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 1.;CM-MAC=ac:f8:cc:db:a4:4c;CMTS-MAC=00:01:5c:b3:b6:5d;CM-QOS=1.1;CM-VER=3.1;
Fri 14/10/2022 13:33:10	3	No Ranging Response received - T3 time-out;CM-MAC=ac:f8:cc:db:a4:4c;CMTS-MAC=00:01:5c:b3:b6:5d;CM-QOS=1.1;CM-VER=3.1;
Fri 14/10/2022 14:35:15	6	CM-STATUS message sent. Event Type Code: 24; Chan ID: 33; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 1.;CM-MAC=ac:f8:cc:db:a4:4c;CMTS-MAC=00:01:5c:b3:b6:5d;CM-QOS=1.1;CM-VER=3.1;
Sat 15/10/2022 00:38:26	6	US profile assignment change. US Chan ID: 27; Previous Profile: 12; New Profile: 11.;CM-MAC=ac:f8:cc:db:a4:4c;CMTS-MAC=00:01:5c:b3:b6:5d;CM-QOS=1.1;CM-VER=3.1;
Sat 15/10/2022 00:49:06	6	CM-STATUS message sent. Event Type Code: 24; Chan ID: 33; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 1.;CM-MAC=ac:f8:cc:db:a4:4c;CMTS-MAC=00:01:5c:b3:b6:5d;CM-QOS=1.1;CM-VER=3.1;
Sat 15/10/2022 01:12:48	6	US profile assignment change. US Chan ID: 27; Previous Profile: 11; New Profile: 10.;CM-MAC=ac:f8:cc:db:a4:4c;CMTS-MAC=00:01:5c:b3:b6:5d;CM-QOS=1.1;CM-VER=3.1;
Sat 15/10/2022 03:49:22	6	CM-STATUS message sent. Event Type Code: 24; Chan ID: 33; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 1.;CM-MAC=ac:f8:cc:db:a4:4c;CMTS-MAC=00:01:5c:b3:b6:5d;CM-QOS=1.1;CM-VER=3.1;
Sat 15/10/2022 05:23:44	6	US profile assignment change. US Chan ID: 27; Previous Profile: 11; New Profile: 10.;CM-MAC=ac:f8:cc:db:a4:4c;CMTS-MAC=00:01:5c:b3:b6:5d;CM-QOS=1.1;CM-VER=3.1;
Sat 15/10/2022 06:49:34	6	CM-STATUS message sent. Event Type Code: 24; Chan ID: 33; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 1.;CM-MAC=ac:f8:cc:db:a4:4c;CMTS-MAC=00:01:5c:b3:b6:5d;CM-QOS=1.1;CM-VER=3.1;
Sat 15/10/2022 07:19:05	6	US profile assignment change. US Chan ID: 27; Previous Profile: 10; New Profile: 11.;CM-MAC=ac:f8:cc:db:a4:4c;CMTS-MAC=00:01:5c:b3:b6:5d;CM-QOS=1.1;CM-VER=3.1;
Sat 15/10/2022 08:14:45	6	CM-STATUS message sent. Event Type Code: 24; Chan ID: 33; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 1.;CM-MAC=ac:f8:cc:db:a4:4c;CMTS-MAC=00:01:5c:b3:b6:5d;CM-QOS=1.1;CM-VER=3.1;
Sat 15/10/2022 08:25:50	6	US profile assignment change. US Chan ID: 27; Previous Profile: 11; New Profile: 12.;CM-MAC=ac:f8:cc:db:a4:4c;CMTS-MAC=00:01:5c:b3:b6:5d;CM-QOS=1.1;CM-VER=3.1;
Sat 15/10/2022 08:36:29	6	CM-STATUS message sent. Event Type Code: 24; Chan ID: 33; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 1.;CM-MAC=ac:f8:cc:db:a4:4c;CMTS-MAC=00:01:5c:b3:b6:5d;CM-QOS=1.1;CM-VER=3.1;

[Bert]

I see uncorrectables and lots of T3 time outs.

This is a very old subscriber takeover point, which can be replaced free of charge by a Ziggo technician.

[tobiastheebe]

Furthermore, the 4-way splitter is outdated and low quality. This splitter should be replaced with a POA-254 (preferably) or POA-01-B splitter, with an amplifier (FRA-752X) for connecting TV and/or set-top boxes.

[Erik P]

Hi @stretch47,

Welcome! Let's replace the takeover point and solve the problems 💪
The engineer will help you Thursday between 0800-1300 hour. You can change the appointment in Mijn Ziggo if you want.

Please let us know if it solved after the visit of the engineer 🙂

[stretch47]

Thank you for arranging this visit.

The engineer came today and replaced the "takeover point". See attached photo. 

The photo obviously indicates the old 4 way splitter was replaced too. 

(I said to the engineer that I only need two outputs at this time, the modem and the TV set top box. So he only installed a two-way splitter. Which is fine. For today. But I am not sure how to adjust this installation to get a 4-way split later if my needs change.)

DOCSIS 3.1 upstream power is now 37.2 dbmv (previously it was 41.5).

After the technician left, I rebooted the modem to get a new "US Profile" (I believe this resets the count of uncorrectable errors). I have refreshed the logs a few times and the number of uncorrectables is not zero and grows steadily. After 15 minutes the new profile now shows millions of corrected errors and dozens of uncorrectable errors. So I believe the uncorrectable errors are still present. Whenever I refresh the page the  number grows a little.

Of course I don't actually care about errors as long as my internet service works perfectly. But if the modem reboots then I think we will have to investigate other solutions.

[tobiastheebe]

You could install a second POA-01-B splitter directly onto the first/current POA-01-B, this will allow you to connect two TVs/set-top boxes. You may also consider connecting an amplifier (e.g. FRA-75X) to the POA-01-B, which allows you to connect four TVs/set-top boxes.

A two-way splitter has less attenuation than the four-way splitter (~4 dB instead of ~8 dB), this matches the ~5 dBmV decrease in US power levels you noticed. OFDMA transmit power should be between 30 and 45 dBmV, 37.2 dBmV is perfect.

The 'US profile assignment change' indicate an IUC (Interval Usage Code) switch on the OFDMA channel. These events are common on DOCSIS 3.1 modems, as well as a tiny amount of uncorrectable errors on the OFDM channel.

[stretch47]

Quick update.
 
The network statistics still show various errors.  The modem did reboot itself once after about an hour.
 
So I tried bypassing the splitter altogether to see if anything would improve. I reconnected ONLY the modem directly to the 'takeover point' and rebooted the modem manually.

Uncorrectables and T3 errors all seem to be happening still.

The current configuration is the simplest, most direct connection possible. If it still reboots then I have to assume some other solution will be needed.

Again, I don't really care about a few uncorrectable errors by themselves. What I do care about is interruptions in service that make it impossible to work from home via video calls etc.

At the moment things seem fine so I'll just let the errors accumulate and hope for the best.

[tobiastheebe]

Could you post the event/network log once again? It may not show (the most) recent events due to a known bug with this modem type. The event log you posted earlier shows an outage at Oct. 14 due to initial ranging (upstream) failure, which was resolved at 14:22.

Uncorrectable errors on the OFDM channel are common to this modem type. As long as the data/profile modulation is 4096-QAM continuously, this should not cause issues. As for T3 timeouts, they should not occur continuously/frequently, 2/3 per day is acceptable.

[stretch47]

Sure. At first the logs showed nothing, then they showed some events but mysteriously stopped showing newer ones that I had seen previously. Finally I reloaded the firmware and rebooted. This is currently what I see in the logs (I believe there is nothing missing since the last boot, the last entry was an hour ago) :

Lees meer

Network Log

Time Priority Description

Thu 01/01/1970 01:01:32	3	No Ranging Response received - T3 time-out;CM-MAC=ac:f8:cc:db:a4:4c;CMTS-MAC=00:01:5c:b3:b6:5d;CM-QOS=1.1;CM-VER=3.1;
Thu 01/01/1970 01:01:57	3	No Maintenance Broadcasts for Ranging opportunities received - T2 time-out;CM-MAC=ac:f8:cc:db:a4:4c;CMTS-MAC=00:01:5c:b3:b6:5d;CM-QOS=1.1;CM-VER=3.1;
Thu 01/01/1970 01:01:58	3	No Ranging Response received - T3 time-out;CM-MAC=ac:f8:cc:db:a4:4c;CMTS-MAC=00:01:5c:b3:b6:5d;CM-QOS=1.1;CM-VER=3.1;
Thu 01/01/1970 01:03:37	5	B-INIT-RNG Failure - Retries exceeded;CM-MAC=ac:f8:cc:db:a4:4c;CMTS-MAC=00:01:5c:b3:b6:5d;CM-QOS=1.1;CM-VER=3.1;
Thu 01/01/1970 01:03:39	3	No Ranging Response received - T3 time-out;CM-MAC=ac:f8:cc:db:a4:4c;CMTS-MAC=00:01:5c:b3:b6:5d;CM-QOS=1.1;CM-VER=3.1;
Thu 01/01/1970 01:04:51	5	B-INIT-RNG Failure - Retries exceeded;CM-MAC=ac:f8:cc:db:a4:4c;CMTS-MAC=00:01:5c:b3:b6:5d;CM-QOS=1.1;CM-VER=3.1;
Thu 01/01/1970 01:04:52	3	No Ranging Response received - T3 time-out;CM-MAC=ac:f8:cc:db:a4:4c;CMTS-MAC=00:01:5c:b3:b6:5d;CM-QOS=1.1;CM-VER=3.1;
Thu 20/10/2022 14:01:01	5	MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1;CM-MAC=ac:f8:cc:db:a4:4c;CMTS-MAC=00:01:5c:b3:b6:5d;CM-QOS=1.1;CM-VER=3.1;
Thu 20/10/2022 14:01:38	6	CM-STATUS message sent. Event Type Code: 16; Chan ID: 33; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 3.;CM-MAC=ac:f8:cc:db:a4:4c;CMTS-MAC=00:01:5c:b3:b6:5d;CM-QOS=1.1;CM-VER=3.1;
Thu 20/10/2022 14:01:43	6	US profile assignment change. US Chan ID: 27; Previous Profile: 10; New Profile: 11.;CM-MAC=ac:f8:cc:db:a4:4c;CMTS-MAC=00:01:5c:b3:b6:5d;CM-QOS=1.1;CM-VER=3.1;
Thu 20/10/2022 14:06:01	6	CM-STATUS message sent. Event Type Code: 16; Chan ID: 33; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 3.;CM-MAC=ac:f8:cc:db:a4:4c;CMTS-MAC=00:01:5c:b3:b6:5d;CM-QOS=1.1;CM-VER=3.1;
Thu 20/10/2022 14:21:19	6	US profile assignment change. US Chan ID: 27; Previous Profile: 11; New Profile: 12.;CM-MAC=ac:f8:cc:db:a4:4c;CMTS-MAC=00:01:5c:b3:b6:5d;CM-QOS=1.1;CM-VER=3.1;
Thu 20/10/2022 14:31:53	6	CM-STATUS message sent. Event Type Code: 16; Chan ID: 33; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 3.;CM-MAC=ac:f8:cc:db:a4:4c;CMTS-MAC=00:01:5c:b3:b6:5d;CM-QOS=1.1;CM-VER=3.1;

[tobiastheebe]

I believe the 'outage' at 14:01 was caused by you connecting the modem directly to the AOP? I do notice frequent OFDM FEC lock loss (event type code 16) and the OFDMA IUC/profile falling back to 12.

[stretch47]

Everything in that log is what you get if you "Restore Default" (not just reboot or reload). I didn't touch any cables or anything physical.  I don't see any new log entries at the moment even though I posted that a few hours ago.  Of course it's possible there have been more entries but it's just not showing them to me haha.

The new attached screen shot below was captured 5 hours after the "Restore Default" procedure. 105 million correctables and 10 thousand uncorrectables in the five hours immediately following a fresh system firmware install. Seems like a high rate, but in general I have been able to surf the internet just fine during that time so maybe this is normal.

Also notice at the top of the screen shot the unusual Pre RS and Post RS errors on Channel 32. Not sure why those appear.

Anyway I'm just continuing to monitor all this and wait to see if the system reboots spontaneously or otherwise 'hangs' : *that* is the behavior I find unacceptable, and at the moment it's not doing that, so I'm happy.

[tobiastheebe]

The reason for the spontaneous reset and stability issues may be external (within Ziggo's infrastructure), because of the rapidly increasing (uncorrectable) FEC errors on SC-QAM channel 32 and the OFDM channel.

[Jiri]

Hey @stretch47

It has been a while. How is it going now? 
Is the connection stable? 

[stretch47]

It's difficult to know for sure. None of the other users in the house have reported outages lately. So that's good.

There are still concerning indicators reported in the administrative interface, such as occasional T3 timeouts, uncorrectable errors (always a fast accumulation rate, although the number resets itself from time to time so I've never seen more than 100,000 uncorrectables) and several times every day there will be Event Type Code 16 and 24 in the logs.  Or the logs disappear and I have to reboot the device to see them again. So I am not filled with confidence.

If, in the near future,  service is interrupted in a really noticeable way, I will start a new thread, but for now I guess we can consider this closed..