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Low upstream levels

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New Poster

Low upstream levels

I’ve been having issues with my internet dropping randomly for a few months now. I’ve had techs come out and replace all the lines and I’ve even changed out my modem (SBG6950AC2), hoping this would fix it. However, it has not. I’ve been researching and it seems my upstream power levels are too low (34.50 dBmV across all channels) and my log shows numerous T3 Timeouts.
My downstream is between 4.00 dBmV and 6.70 dBmV with SNR between 40.37 dB to 40.95 dB.

Xfinity should adjust the upstream levels and that should fix my issue, correct? I’m tired of having techs out and the problem not being fixed so I’m trying to fix it without a tech coming out but if they have to then ok.

Unfortunately, I’ve already starting looking at other ISP’s as this is just an issue I CANNOT just live with.
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New Poster

Re: Low upstream levels

This is my log:

Date Time Event ID Event Level Description
8/2/2020 10:41 73040100 6 TLV-11 - unrecognized OID;CM-MAC=c8:63:fc:46:00:b5;CMTS-MAC=94:d4:69:55:91:5e;CM-QOS=1.1;CM-VER=3.0;
8/2/2020 18:18 84000500 3 SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=c8:63:fc:46:00:b5;CMTS-MAC=94:d4:69:55:91:5e;CM-QOS=1.1;CM-VER=3.0;
8/2/2020 18:21 73040100 6 TLV-11 - unrecognized OID;CM-MAC=c8:63:fc:46:00:b5;CMTS-MAC=94:d4:69:55:91:5e;CM-QOS=1.1;CM-VER=3.0;
8/2/2020 20:37 82000200 3 No Ranging Response received - T3 time-out;CM-MAC=c8:63:fc:46:00:b5;CMTS-MAC=94:d4:69:55:91:5e;CM-QOS=1.1;CM-VER=3.0;
8/2/2020 22:22 82000700 3 Unicast Ranging Received Abort Response - initializing MAC;CM-MAC=c8:63:fc:46:00:b5;CMTS-MAC=94:d4:69:55:91:5e;CM-QOS=1.1;CM-VER=3.0;
8/2/2020 22:22 82000200 3 No Ranging Response received - T3 time-out;CM-MAC=c8:63:fc:46:00:b5;CMTS-MAC=94:d4:69:55:91:5e;CM-QOS=1.1;CM-VER=3.0;
8/3/2020 0:11 73040100 6 TLV-11 - unrecognized OID;CM-MAC=c8:63:fc:46:00:b5;CMTS-MAC=94:d4:69:55:91:5e;CM-QOS=1.1;CM-VER=3.0;
8/3/2020 8:13 82000700 3 Unicast Ranging Received Abort Response - initializing MAC;CM-MAC=c8:63:fc:46:00:b5;CMTS-MAC=94:d4:69:55:91:5e;CM-QOS=1.1;CM-VER=3.0;
8/3/2020 8:13 82000200 3 No Ranging Response received - T3 time-out;CM-MAC=c8:63:fc:46:00:b5;CMTS-MAC=94:d4:69:55:91:5e;CM-QOS=1.1;CM-VER=3.0;
8/3/2020 9:55 82000700 3 Unicast Ranging Received Abort Response - initializing MAC;CM-MAC=c8:63:fc:46:00:b5;CMTS-MAC=94:d4:69:55:91:5e;CM-QOS=1.1;CM-VER=3.0;
8/3/2020 9:55 82000200 3 No Ranging Response received - T3 time-out;CM-MAC=c8:63:fc:46:00:b5;CMTS-MAC=94:d4:69:55:91:5e;CM-QOS=1.1;CM-VER=3.0;
8/3/2020 9:56 82000700 3 Unicast Ranging Received Abort Response - initializing MAC;CM-MAC=c8:63:fc:46:00:b5;CMTS-MAC=94:d4:69:55:91:5e;CM-QOS=1.1;CM-VER=3.0;
8/3/2020 9:56 82000200 3 No Ranging Response received - T3 time-out;CM-MAC=c8:63:fc:46:00:b5;CMTS-MAC=94:d4:69:55:91:5e;CM-QOS=1.1;CM-VER=3.0;
8/3/2020 11:01 84000700 5 RCS Partial Service;CM-MAC=c8:63:fc:46:00:b5;CMTS-MAC=94:d4:69:55:91:5e;CM-QOS=1.1;CM-VER=3.0;
8/3/2020 11:01 84000500 3 SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=c8:63:fc:46:00:b5;CMTS-MAC=94:d4:69:55:91:5e;CM-QOS=1.1;CM-VER=3.0;
8/3/2020 11:01 84000700 5 RCS Partial Service;CM-MAC=c8:63:fc:46:00:b5;CMTS-MAC=94:d4:69:55:91:5e;CM-QOS=1.1;CM-VER=3.0;
8/3/2020 11:01 84000500 3 SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=c8:63:fc:46:00:b5;CMTS-MAC=94:d4:69:55:91:5e;CM-QOS=1.1;CM-VER=3.0;
8/3/2020 11:01 84020200 5 Lost MDD Timeout;CM-MAC=c8:63:fc:46:00:b5;CMTS-MAC=94:d4:69:55:91:5e;CM-QOS=1.1;CM-VER=3.0;
8/3/2020 11:02 82000400 3 Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=c8:63:fc:46:00:b5;CMTS-MAC=94:d4:69:55:91:5e;CM-QOS=1.1;CM-VER=3.0;
8/3/2020 11:15 73040100 6 TLV-11 - unrecognized OID;CM-MAC=c8:63:fc:46:00:b5;CMTS-MAC=94:d4:69:55:91:5e;CM-QOS=1.1;CM-VER=3.0;


And my downstream/upstream levels:

Downstream

DCID Freq Power SNR Modulation Octets Correcteds Uncorrectables
Downstream 1 1 391.75 MHz 6.60 dBmV 40.37 dB 256QAM 22230283 0 0
Downstream 2 2 397.75 MHz 6.40 dBmV 40.37 dB 256QAM 25968047 0 0
Downstream 3 3 403.75 MHz 6.10 dBmV 40.37 dB 256QAM 26498653 20 0
Downstream 4 4 409.75 MHz 5.90 dBmV 40.37 dB 256QAM 26472833 16 0
Downstream 5 5 415.75 MHz 5.40 dBmV 40.95 dB 256QAM 19942878 16 0
Downstream 6 6 421.75 MHz 5.50 dBmV 40.95 dB 256QAM 26406789 13 0
Downstream 7 7 433.75 MHz 5.00 dBmV 40.37 dB 256QAM 26667758 0 0
Downstream 8 8 439.75 MHz 4.90 dBmV 40.95 dB 256QAM 26717897 21 0
Downstream 9 9 445.75 MHz 4.50 dBmV 40.37 dB 256QAM 20524108 18 0
Downstream 10 10 457.75 MHz 4.20 dBmV 40.37 dB 256QAM 26332399 0 0
Downstream 11 11 463.75 MHz 4.30 dBmV 40.95 dB 256QAM 26722123 0 0
Downstream 12 12 469.75 MHz 4.20 dBmV 40.37 dB 256QAM 26691983 16 0
Downstream 13 13 475.75 MHz 4.20 dBmV 40.95 dB 256QAM 19098491 9 0
Downstream 14 14 481.75 MHz 4.20 dBmV 40.37 dB 256QAM 25351691 0 0
Downstream 15 15 487.75 MHz 4.10 dBmV 40.37 dB 256QAM 25398743 7 0
Downstream 16 16 493.75 MHz 3.90 dBmV 40.95 dB 256QAM 25385029 6 0
Reset FEC Counters
Upstream

UCID Freq Power Channel Type Symbol Rate Modulation
Upstream 1 7 22.80 MHz 34.50 dBmV DOCSIS2.0 (ATDMA) 5120 kSym/s 64QAM
Upstream 2 8 16.40 MHz 34.50 dBmV DOCSIS2.0 (ATDMA) 5120 kSym/s 64QAM
Upstream 3 6 29.20 MHz 33.00 dBmV DOCSIS2.0 (ATDMA) 5120 kSym/s 64QAM
Upstream 4 5 35.60 MHz 34.50 dBmV DOCSIS2.0 (ATDMA) 5120 kSym/s 64QAM


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Diamond Problem Solver

Re: Low upstream levels

Your upstream is only a 1/2 dB to 2db out of spec, something an attenuator would adjust. 35-50db is the range for upstream levels. Can’t say if it will fix your problems, but upstream (all levels) aren’t fixed/adjusted remotely, it will require a tech visit

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New Poster
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Diamond Problem Solver

Re: Low upstream levels

Yes but not 12db, maybe between 3 and 6db because whatever amount you use it will lower your downstream by the same amount.

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New Poster

Re: Low upstream levels

So just use one correct?
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Diamond Problem Solver

Re: Low upstream levels

One attenuator but one labeled 3db or 6 dB, the one you linked to is 12db and that’s too much

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New Poster

Re: Low upstream levels

Oh, got it. I thought it said 6db but because it was a 2 pack it made it 12db. I’ll grab one that it just 6db. Hopefully, that helps. I did contact Tech support but they didn’t really get what I was saying. She kept talking about my upload speed and then said 31.7 Db (which is the upstream power level she got) was standard. Ultimately, she created a ticket and said a higher tech team would call me and schedule a tech if necessary. I have no clue if this is the correct procedure.
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Expert

Re: Low upstream levels

FWIW. The upstream power is fine. We've had posters here with 28 dB of upstream power and their internet works fine. 

 

It may just be a very clean, low attenuation, and noise free return path. It may be correct for your local system specs. There are spec variances between individual systems.

 

Putting an attenuator in the line will only make the upstream power as read at the modem look prettier. It doesn't really do anything. The power is controlled automatically by commands from the cable modem termination signal at the local headend facility.

 



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New Poster

Re: Low upstream levels

So if it’s not the upstream power levels that’s causing my internet connection drops and t3 timeouts, what else could it be? I’ve had techs come out and test and replace all the lines and can’t find a problem. I switched out the modem thinking it might be that but my previous modem worked fine before moving here. I’m out of options at this point.