Intermittently Slow Downstream. Upstream unaffected.

Can someone interpret potential issues from the tables I'm including?

 

Spectrum user here in Raleigh, NC.

200 down 20 up package. (maybe 10 up, idk);

This is the first time  the downstream via speedtests has gone from ~200 Mbps  to  anywhere from ~1 Mbps to no higher than ~6 Mbps. Upstream never effected--stays consistently around ~10 Mbps (I believe that's what I pay for...)

 

I've been in this house less than 1 month and the internet service here is only about 2 weeks in.  Oddly enough, at the apartment I was in prior, the same thing would happen. Granted, I had a different modem/router then than now, it was still always the same symptoms. ~100 Mbps maxx package dipping to no more than ~5 Mbps... Would come back to life days later or sometimes when I cave, call tech support, and they "resend lost signals" to my modem. (Apparently they got my modem stuck permanently in recovery mode when we moved to this house.)

 

I'm running an AC1900 modem/router.  Signal logs below:

 

*Note: I'm phishing for input and items to discuss with the tech that is already scheduled to come out tomorrow (Feb. 4, 2018) for this issue. *   Thank you in advance!

 

Downstream Bonded Channels:

ChannelLock StatusModulationChannel IDFrequencyPowerSNRCorrectedUncorrectables
1LockedQAM2569507000000 Hz13.2 dBmV29.5 dB2186321384
2LockedQAM25610513000000 Hz13.3 dBmV29.5 dB2709901108
3LockedQAM25611519000000 Hz13.4 dBmV29.5 dB326993822458
4LockedQAM25612525000000 Hz13.6 dBmV29.5 dB34764694169
5LockedQAM25613531000000 Hz13.6 dBmV29.5 dB3801718358
6LockedQAM25614537000000 Hz13.5 dBmV29.3 dB53518134976
7LockedQAM25615543000000 Hz13.3 dBmV29.2 dB81048458109
8LockedQAM25616549000000 Hz13.1 dBmV29.0 dB1121135221751
9LockedQAM25617555000000 Hz13.1 dBmV28.9 dB1465634759989
10LockedQAM25618561000000 Hz12.9 dBmV28.8 dB1829141976914
11LockedQAM25619567000000 Hz12.3 dBmV28.3 dB439955511828487
12LockedQAM25620573000000 Hz12.3 dBmV28.2 dB516261314699012
13LockedQAM25621579000000 Hz12.4 dBmV28.1 dB453808894267081
14LockedQAM25622585000000 Hz12.7 dBmV28.2 dB428909922929853
15LockedQAM25623591000000 Hz12.8 dBmV28.2 dB455710684428558
16LockedQAM25624597000000 Hz12.8 dBmV28.0 dB478177948970156

 

Upstream Bonded Channels:

ChannelLock StatusUS Channel TypeChannel IDSymbol RateFrequencyPower
1LockedATDMA35120 Ksym/sec30400000 Hz41.3 dBmV
2LockedATDMA25120 Ksym/sec24000000 Hz41.3 dBmV
3LockedTDMA12560 Ksym/sec19200000 Hz40.0 dBmV
4LockedATDMA45120 Ksym/sec36800000 Hz41.3 dBmV

 

Event Log:

Sat Feb 03 07:56:47 2018Warning (5)MDD message timeout;CM-MAC=78:23:ae:ff:a2:de;CMTS-MAC=00:17:10:88:ce:45;CM-QOS=1.1;CM-VER=3.0;
Sat Feb 03 07:33:11 2018Critical (3)SYNC Timing Synchronization failure - Failed to acquire FEC framing;CM-MAC=78:23:ae:ff:a2:de;CMTS-MAC=00:17:10:88:ce:45;CM-QOS=1.1;CM-VER=3.0;
Sat Feb 03 07:32:59 2018Warning (5)MDD message timeout;CM-MAC=78:23:ae:ff:a2:de;CMTS-MAC=00:17:10:88:ce:45;CM-QOS=1.1;CM-VER=3.0;
Sat Feb 03 07:29:28 2018Notice (6)TLV-11 - unrecognized OID;CM-MAC=78:23:ae:ff:a2:de;CMTS-MAC=00:17:10:88:ce:45;CM-QOS=1.1;CM-VER=3.0;
Sat Feb 03 07:29:27 2018Error (4)Missing BP Configuration Setting TLV Type: 17.9;CM-MAC=78:23:ae:ff:a2:de;CMTS-MAC=00:17:10:88:ce:45;CM-QOS=1.1;CM-VER=3.0;
Sat Feb 03 07:29:26 2018Error (4)Missing BP Configuration Setting TLV Type: 17.8;CM-MAC=78:23:ae:ff:a2:de;CMTS-MAC=00:17:10:88:ce:45;CM-QOS=1.1;CM-VER=3.0;
Fri Feb 02 11:36:26 2018Critical (3)Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=78:23:ae:ff:a2:de;CMTS-MAC=00:17:10:88:ce:45;CM-QOS=1.1;CM-VER=3.0;
Time Not EstablishedCritical (3)SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=78:23:ae:ff:a2:de;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0;
Time Not EstablishedCritical (3)SYNC Timing Synchronization failure - Failed to acquire FEC framing;CM-MAC=78:23:ae:ff:a2:de;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0;
Time Not EstablishedCritical (3)SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=78:23:ae:ff:a2:de;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0;
Time Not EstablishedCritical (3)SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=78:23:ae:ff:a2:de;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0;
Fri Feb 02 08:39:58 2018Critical (3)SYNC Timing Synchronization failure - Failed to acquire FEC framing;CM-MAC=78:23:ae:ff:a2:de;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0;
Fri Feb 02 08:39:51 2018Critical (3)Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=78:23:ae:ff:a2:de;CMTS-MAC=00:17:10:88:ce:45;CM-QOS=1.1;CM-VER=3.0;
Fri Feb 02 08:39:51 2018Critical (3)SYNC Timing Synchronization failure - Failed to acquire FEC framing;CM-MAC=78:23:ae:ff:a2:de;CMTS-MAC=00:17:10:88:ce:45;CM-QOS=1.1;CM-VER=3.0;
Fri Feb 02 08:39:49 2018Critical (3)Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=78:23:ae:ff:a2:de;CMTS-MAC=00:17:10:88:ce:45;CM-QOS=1.1;CM-VER=3.0;
Fri Feb 02 08:39:49 2018Critical (3)SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=78:23:ae:ff:a2:de;CMTS-MAC=00:17:10:88:ce:45;CM-QOS=1.1;CM-VER=3.0;
Fri Feb 02 08:39:48 2018Critical (3)Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=78:23:ae:ff:a2:de;CMTS-MAC=00:17:10:88:ce:45;CM-QOS=1.1;CM-VER=3.0;
Fri Feb 02 08:39:48 2018Critical (3)SYNC Timing Synchronization failure - Failed to acquire FEC framing;CM-MAC=78:23:ae:ff:a2:de;CMTS-MAC=00:17:10:88:ce:45;CM-QOS=1.1;CM-VER=3.0;
Fri Feb 02 08:39:43 2018Critical (3)Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=78:23:ae:ff:a2:de;CMTS-MAC=00:17:10:88:ce:45;CM-QOS=1.1;CM-VER=3.0;
Fri Feb 02 08:39:43 2018Critical (3)SYNC Timing Synchronization failure - Failed to acquire FEC framing;CM-MAC=78:23:ae:ff:a2:de;CMTS-MAC=00:17:10:88:ce:45;CM-QOS=1.1;CM-VER=3.0;
Fri Feb 02 08:39:24 2018Critical (3)SYNC Timing Synchronization failure - Failed to acquire FEC framing;CM-MAC=78:23:ae:ff:a2:de;CMTS-MAC=00:17:10:88:ce:45;CM-QOS=1.1;CM-VER=3.0;
Fri Feb 02 08:37:43 2018Critical (3)SYNC Timing Synchronization failure - Failed to acquire FEC framing;CM-MAC=78:23:ae:ff:a2:de;CMTS-MAC=00:17:10:88:ce:45;CM-QOS=1.1;CM-VER=3.0;
Wed Jan 31 02:57:53 2018Critical (3)Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=78:23:ae:ff:a2:de;CMTS-MAC=00:17:10:88:ce:45;CM-QOS=1.1;CM-VER=3.0;
Time Not EstablishedCritical (3)No Ranging Response received - T3 time-out
Time Not EstablishedCritical (3)No Maintenance Broadcasts for Ranging opportunities received - T2 time-out;CM-MAC=78:23:ae:ff:a2:de;CMTS-MAC=00:17:10:88:ce:45;CM-QOS=1.0;CM-VER=3.0;
Time Not EstablishedCritical (3)No Ranging Response received - T3 time-out
Time Not EstablishedCritical (3)No Maintenance Broadcasts for Ranging opportunities received - T2 time-out;CM-MAC=78:23:ae:ff:a2:de;CMTS-MAC=00:17:10:88:ce:45;CM-QOS=1.0;CM-VER=3.0;
Time Not EstablishedCritical (3)No Ranging Response received - T3 time-out
Time Not EstablishedCritical (3)SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=78:23:ae:ff:a2:de;CMTS-MAC=00:17:10:88:ce:45;CM-QOS=1.0;CM-VER=3.0;
Time Not EstablishedCritical (3)SYNC Timing Synchronization failure - Failed to acquire FEC framing;CM-MAC=78:23:ae:ff:a2:de;CMTS-MAC=00:17:10:88:ce:45;CM-QOS=1.0;CM-VER=3.0;
Time Not EstablishedCritical (3)SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=78:23:ae:ff:a2:de;CMTS-MAC=00:17:10:88:ce:45;CM-QOS=1.0;CM-VER=3.0;
Time Not EstablishedCritical (3)SYNC Timing Synchronization failure - Failed to acquire FEC framing;CM-MAC=78:23:ae:ff:a2:de;CMTS-MAC=00:17:10:88:ce:45;CM-QOS=1.0;CM-VER=3.0;
Time Not EstablishedCritical (3)SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=78:23:ae:ff:a2:de;CMTS-MAC=00:17:10:88:ce:45;CM-QOS=1.0;CM-VER=3.0;
Time Not EstablishedCritical (3)SYNC Timing Synchronization failure - Failed to acquire FEC framing;CM-MAC=78:23:ae:ff:a2:de;CMTS-MAC=00:17:10:88:ce:45;CM-QOS=1.0;CM-VER=3.0;
Time Not EstablishedCritical (3)SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=78:23:ae:ff:a2:de;CMTS-MAC=00:17:10:88:ce:45;CM-QOS=1.0;CM-VER=3.0;
Time Not EstablishedCritical (3)SYNC Timing Synchronization failure - Failed to acquire FEC framing;CM-MAC=78:23:ae:ff:a2:de;CMTS-MAC=00:17:10:88:ce:45;CM-QOS=1.0;CM-VER=3.0;
Time Not EstablishedCritical (3)SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=78:23:ae:ff:a2:de;CMTS-MAC=00:17:10:88:ce:45;CM-QOS=1.0;CM-VER=3.0;
Time Not EstablishedCritical (3)SYNC Timing Synchronization failure - Failed to acquire FEC framing;CM-MAC=78:23:ae:ff:a2:de;CMTS-MAC=00:17:10:88:ce:45;CM-QOS=1.0;CM-VER=3.0;
Time Not EstablishedCritical (3)SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=78:23:ae:ff:a2:de;CMTS-MAC=00:17:10:88:ce:45;CM-QOS=1.0;CM-VER=3.0;
Time Not EstablishedCritical (3)SYNC Timing Synchronization failure - Failed to acquire FEC framing;CM-MAC=78:23:ae:ff:a2:de;CMTS-MAC=00:17:10:88:ce:45;CM-QOS=1.0;CM-VER=3.0;
Time Not EstablishedCritical (3)SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=78:23:ae:ff:a2:de;CMTS-MAC=00:17:10:88:ce:45;CM-QOS=1.0;CM-VER=3.0;
Time Not EstablishedCritical (3)SYNC Timing Synchronization failure - Failed to acquire FEC framing;CM-MAC=78:23:ae:ff:a2:de;CMTS-MAC=00:17:10:88:ce:45;CM-QOS=1.0;CM-VER=3.0;
Time Not EstablishedCritical (3)SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=78:23:ae:ff:a2:de;CMTS-MAC=00:17:10:88:ce:45;CM-QOS=1.0;CM-VER=3.0;
Time Not EstablishedCritical (3)No Maintenance Broadcasts for Ranging opportunities received - T2 time-out;CM-MAC=78:23:ae:ff:a2:de;CMTS-MAC=00:17:10:88:ce:45;CM-QOS=1.0;CM-VER=3.0;
Time Not EstablishedCritical (3)No Ranging Response received - T3 time-out
Time Not EstablishedCritical (3)No Maintenance Broadcasts for Ranging opportunities received - T2 time-out;CM-MAC=78:23:ae:ff:a2:de;CMTS-MAC=00:17:10:88:ce:45;CM-QOS=1.0;CM-VER=3.0;
Time Not EstablishedCritical (3)No Ranging Response received - T3 time-out
Time Not EstablishedCritical (3)No Maintenance Broadcasts for Ranging opportunities received - T2 time-out;CM-MAC=78:23:ae:ff:a2:de;CMTS-MAC=00:17:10:88:ce:45;CM-QOS=1.0;CM-VER=3.0;
Time Not EstablishedCritical (3)No Ranging Response received - T3 time-out
Time Not EstablishedCritical (3)

No Maintenance Broadcasts for Ranging opportunities received - T2 time-out;CM-MAC=78:23:ae:ff:a2:de;CMTS-MAC=00:17:10:88:ce:45;CM-QOS=1.0;CM-VER=3.0;

 

 

6 REPLIES
Valued Participant

Re: Intermittently Slow Downstream. Upstream unaffected.

Your downstream signals are out of spec. Should be in the range of +8 dBmV to -8 dBmV. Anything outside of that, your connection will be unreliable.

 

I’m sure one of the more experienced folks here will respond soon, with more information.

Re: Intermittently Slow Downstream. Upstream unaffected.

Here is an updated Downstream table now.

My service is now working completely fine. Speedtests are ~200 Mbps down, ~10 Mbps up.

6 hours later.  i have done nothing to fix/change anything. 

There is nothing new in the event log.

Upstream table remains unchanged. Maybe one power varying by ~.2 dBmV

 

ChannelLock StatusModulationChannel IDFrequencyPowerSNRCorrectedUncorrectables
1LockedQAM2569507000000 Hz11.7 dBmV32.8 dB9155228452
2LockedQAM25610513000000 Hz11.7 dBmV33.1 dB11213242269
3LockedQAM25611519000000 Hz11.8 dBmV33.1 dB1351300822670
4LockedQAM25628621000000 Hz12.0 dBmV31.5 dB145106584491
5LockedQAM25613531000000 Hz12.0 dBmV33.1 dB16118801756
6LockedQAM25614537000000 Hz11.8 dBmV33.0 dB228393846167
7LockedQAM25615543000000 Hz11.5 dBmV32.7 dB3496710513265
8LockedQAM25616549000000 Hz11.2 dBmV32.6 dB4852704637398
9LockedQAM25617555000000 Hz11.1 dBmV32.4 dB65097485100308
10LockedQAM25630633000000 Hz12.3 dBmV31.4 dB22538940911025040
11LockedQAM25619567000000 Hz9.5 dBmV31.8 dB1949695273805065
12LockedQAM25620573000000 Hz9.6 dBmV31.6 dB25057052210231662
13LockedQAM25621579000000 Hz10.3 dBmV31.6 dB25306635110703880
14LockedQAM25622585000000 Hz10.7 dBmV31.7 dB2316937507252098
15LockedQAM25623591000000 Hz10.8 dBmV31.7 dB25760589711205902
16LockedQAM25624597000000 Hz10.9 dBmV31.5 dB30629692824319983
Valued Participant

Re: Intermittently Slow Downstream. Upstream unaffected.

Still too high. I had this issue and sometimes it would be fine for a bit, but I started having trouble again.

 

Those downstream signals need to be between +8 dBmV to -8 dBmV for the service to work reliably. When the tech comes out, they should see this right away.  Mention it to him/her when they arrive.

 

I'm sure MsRaye or Karl will chime in soon with some more info. They are the real pros here.

 

Highlighted
Expert

Re: Intermittently Slow Downstream. Upstream unaffected.

Get spectrum out... there is a major ds s/n issue. Verify the modem is directly connected to the outside line and there's no amplifers in line.

your s/n is too low. correcteds way out of spec

not exactly a too high  level issue. maybe out on the street.

 

 

Re: Intermittently Slow Downstream. Upstream unaffected.

Performance-wise, the problem has not resurfaced, since a tech did come out...

The uncorrecteds are still about the same though.  I'll be calling another tech out just for investigative work.

Thank you for the input.

Expert

Re: Intermittently Slow Downstream. Upstream unaffected.

Are you sure there's not an amplifier in house?

Something is grossly off.