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Connection drops and low speed on wifi. Brand new gateway.

Regular Visitor

Connection drops and low speed on wifi. Brand new gateway.

I just became an xfinity customer again on 8/15/19. I bought the 400mbps extreme internet package. I had a Netgear N450 (worked flawlessly at my last location~2 years ago on a 150mbps plan) router from a previous internet plan that I was using and it was dropping internet about once an hour for 5-10 minutes and it would come back after that. I am also getting a slower speed than I figured over wifi. I get 430-460 mbps wired and the best device on wifi will only pull about 60 mbps down.

I figured the gateway might be bad, so i purchased a arris sbg6900-ac gateway to try and eliminate the problem. I was still having equivilent amount of dropped connections, so I had a technician out. He replaced the cable from the junction box on the house to the house plate and from there to the modem and tv. This cleared up my drops slightly. Still getting atleast 2-3 drops aday. I contacted Arris Tech support to see if the could assist me. They went through my down stream power and SNR readings and said they were fine. When we got to the upstream I have 4 bonded channels all of which are locked but the power levels were 40.0-41.5 on the highest channel. The Arris Tech support guy immediately said that this was the issue for dropped connections and slow wifi. I questioned that the low power level on the upstream would effect the slow downstream speed over wifi, but he insisted that what it was. So I called xfinity and explained this and a lady ran some tests and said it was ok. I tried to tell her what the Arris Tech said, but she said it's not their device and they can't see in it to test anything in the device itself. I kind of feel like Im getting the run around now. I will post a few of the event log errors I've been getting below.

 

Let me know if anything above needs to be clarified. Thanks for any help you can offer.

 

Levi

 

Fri Aug 30 17:27:56 2019 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=bc:2e:48:85:b2:a0;CMTS-MAC=00:01:5c:9e:54:6e;CM-QOS=1.1;CM-VER=3.0;
Fri Aug 30 15:53:27 2019 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=bc:2e:48:85:b2:a0;CMTS-MAC=00:01:5c:9e:54:6e;CM-QOS=1.1;CM-VER=3.0;
Fri Aug 30 15:53:02 2019 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=bc:2e:48:85:b2:a0;CMTS-MAC=00:01:5c:9e:54:6e;CM-QOS=1.1;CM-VER=3.0;
Fri Aug 30 06:22:38 2019 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=bc:2e:48:85:b2:a0;CMTS-MAC=00:01:5c:9e:54:6e;CM-QOS=1.1;CM-VER=3.0;
Expert

Re: Connection drops and low speed on wifi. Brand new gateway.

You need to post the signal status numbers as well.


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Regular Visitor

Re: Connection drops and low speed on wifi. Brand new gateway.

 

 
Startup Procedure
Procedure Status Comment
Acquire Downstream Channel   Locked
Connectivity State OK Operational
Boot State OK Operational
Configuration File OK  
Security Enabled BPI+
DOCSIS Network Access Enabled Allowed  

 
Downstream Bonded Channels
Channel Lock Status Modulation Channel ID Frequency Power SNR Corrected Uncorrectables
1 Locked QAM256 22 525000000 Hz 6.6 dBmV 40.9 dB 0 0
2 Locked QAM256 23 531000000 Hz 6.5 dBmV 40.8 dB 0 0
3 Locked QAM256 24 537000000 Hz 6.8 dBmV 41.1 dB 0 0
4 Locked QAM256 25 543000000 Hz 6.4 dBmV 40.7 dB 0 0
5 Locked QAM256 26 549000000 Hz 6.0 dBmV 40.4 dB 0 0
6 Locked QAM256 27 555000000 Hz 6.6 dBmV 40.8 dB 6 0
7 Locked QAM256 28 561000000 Hz 6.7 dBmV 40.9 dB 0 0
8 Locked QAM256 29 567000000 Hz 6.1 dBmV 40.3 dB 0 0
9 Locked QAM256 30 573000000 Hz 6.1 dBmV 40.3 dB 0 0
10 Locked QAM256 31 579000000 Hz 6.8 dBmV 40.8 dB 0 0
11 Locked QAM256 32 585000000 Hz 6.2 dBmV 40.3 dB 0 0
12 Locked QAM256 33 591000000 Hz 5.6 dBmV 40.1 dB 0 0
13 Locked QAM256 34 597000000 Hz 6.0 dBmV 40.2 dB 5 0
14 Locked QAM256 35 603000000 Hz 6.3 dBmV 40.3 dB 0 0
15 Locked QAM256 36 609000000 Hz 6.0 dBmV 40.2 dB 0 0
16 Locked QAM256 37 615000000 Hz 6.3 dBmV 40.2 dB 1 0

 
Upstream Bonded Channels
Channel Lock Status US Channel Type Channel ID Symbol Rate Frequency Power
1 Locked ATDMA 3 5120 Ksym/sec 23000000 Hz 41.2 dBmV
2 Locked ATDMA 1 5120 Ksym/sec 36100000 Hz 40.5 dBmV
3 Locked ATDMA 2 5120 Ksym/sec 29600000 Hz 42.0 dBmV
4 Locked ATDMA 4 5120 Ksym/sec 16500000 Hz 41.5 dBmV


 
Expert

Re: Connection drops and low speed on wifi. Brand new gateway.

The stats are o/k.  So, for a test, does a computer hardwired directly to the router / gateway device with an ethernet cable have the same problem ?



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Regular Visitor

Re: Connection drops and low speed on wifi. Brand new gateway.

My hardwired PC drops the connection aswell as wifi devices when I get the time out issue. I get much better speed hard wired (400+ mbps)  than wifi connections(40-60) though.

Expert

Re: Connection drops and low speed on wifi. Brand new gateway.

Even though the signal stats looked o/k at that snapshot in time, the error log entries confirm that something is going on. Perhaps there is noise ingress into the line(s) somewhere.

 

There are other signal stat figures that can't be read by the modem. They are the "Upstream Rx Power" (Upstream Receive Power Level), the "Upstream SNR Ch." (Upstream Signal To Noise Ratio), and the "Upstream ICFR" (In Channel Frequency Response). These are as equally important in diagnosing connectivity issues as are the modem's stats.


I'm going to escalate your issue to the Comcast corporate employees that are available to these boards. They can check the CMTS (Cable Modem Termination System) for any real time degradation and / or error reports, see your node / cable plant and modem health, and see whether or not everything is in the green zone. They can also see a history plot for the modem and poll for those upstream receive signal stats.

You should get a reply here in your topic. Good luck !



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Official Employee Digital Care

Re: Connection drops and low speed on wifi. Brand new gateway.


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Regular Visitor

Re: Connection drops and low speed on wifi. Brand new gateway.

I know the issue is still being looked into, but I wanted to give an update. I recently started getting a ton of corrected and uncorrcetables. as seen below.

Status - Connection

The statuses listed show the connection state of the cable modem. They are used by your service provider to evaluate the operation of the cable modem.

 
Startup Procedure
Procedure Status Comment
Acquire Downstream Channel   Locked
Connectivity State OK Operational
Boot State OK Operational
Configuration File OK  
Security Enabled BPI+
DOCSIS Network Access Enabled Allowed  

 
Downstream Bonded Channels
Channel Lock Status Modulation Channel ID Frequency Power SNR Corrected Uncorrectables
1 Locked QAM256 22 525000000 Hz 5.8 dBmV 40.8 dB 12535 8139
2 Locked QAM256 23 531000000 Hz 5.6 dBmV 40.7 dB 12749 7845
3 Locked QAM256 24 537000000 Hz 5.9 dBmV 41.0 dB 12413 7906
4 Locked QAM256 25 543000000 Hz 5.4 dBmV 40.5 dB 12287 7922
5 Locked QAM256 26 549000000 Hz 5.1 dBmV 40.3 dB 12377 8176
6 Locked QAM256 27 555000000 Hz 5.8 dBmV 40.7 dB 11852 7665
7 Locked QAM256 28 561000000 Hz 5.9 dBmV 40.9 dB 11744 7414
8 Locked QAM256 29 567000000 Hz 5.3 dBmV 40.3 dB 11845 7744
9 Locked QAM256 30 573000000 Hz 5.3 dBmV 40.3 dB 11662 7718
10 Locked QAM256 31 579000000 Hz 5.9 dBmV 40.7 dB 11147 7446
11 Locked QAM256 32 585000000 Hz 5.3 dBmV 40.2 dB 11476 7800
12 Locked QAM256 33 591000000 Hz 4.7 dBmV 40.0 dB 11567 7885
13 Locked QAM256 34 597000000 Hz 5.1 dBmV 40.1 dB 11195 7788
14 Locked QAM256 35 603000000 Hz 5.3 dBmV 40.2 dB 10902 7451
15 Locked QAM256 36 609000000 Hz 5.1 dBmV 40.1 dB 10883 7327
16 Locked QAM256 37 615000000 Hz 5.3 dBmV 40.1 dB 10734 7137

 
Upstream Bonded Channels
Channel Lock Status US Channel Type Channel ID Symbol Rate Frequency Power
1 Locked ATDMA 2 5120 Ksym/sec 29600000 Hz 42.5 dBmV
2 Locked ATDMA 1 5120 Ksym/sec 36100000 Hz 41.8 dBmV
3 Locked ATDMA 3 5120 Ksym/sec 23000000 Hz 42.5 dBmV
4 Locked ATDMA 4 5120 Ksym/sec 16500000 Hz 42.3 dBmV