mjs9876543210's profile

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1 Message

Sun, Aug 2, 2020 1:00 PM

Intermittent connectivity issues, even when hardwired, even with great throughput and latency

Hi -

 

I am hardwired to the Xfi modem (ARRIS TG3482G). I have excellent throughput (900 Mbps down, 35 Mbps up) and 8-15ms ping response times.

 

However I am not able to reliably carry on a single video conference call, sometimes even with video off. I know the problem is on my side because none of the other participants are having issues. The problem is intermittent - sometimes it's fine for many minutes, sometimes it's problematic. I assumed the problem was due to my wireless setup, but it still occurs even when hard-wired, so I'm confident it's not wireless-related. All cables from the splitter down are new Cat6 (or better) cable. There's only one splitter, and it's one of the ones recommended elsewhere in this forum for Gigabit connections.

 

Here are the upstream and downstream signals.

 

IndexLock StatusFrequencySNRPower LevelModulation
Downstream
Channel Bonding Value
20
0
8
9
10
11
12
13
14
15
16
17
18
19
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
 
Locked
NotLocked
Locked
Locked
Locked
Locked
Locked
Locked
Locked
Locked
Locked
Locked
Locked
Locked
Locked
Locked
Locked
Locked
Locked
Locked
Locked
Locked
Locked
Locked
Locked
Locked
Locked
Locked
Locked
Locked
Locked
Locked
Locked
525000000
 
447000000
453000000
459000000
465000000
471000000
477000000
483000000
489000000
495000000
507000000
513000000
519000000
531000000
537000000
543000000
549000000
555000000
561000000
567000000
573000000
579000000
585000000
591000000
597000000
603000000
609000000
615000000
621000000
627000000
633000000
713600000
38.605377
 
38.983261
38.983261
38.605377
40.366287
40.366287
38.983261
38.983261
38.983261
38.983261
38.605377
38.983261
38.605377
38.605377
38.605377
38.605377
38.605377
38.605377
38.605377
38.605377
38.605377
38.605377
38.605377
38.983261
38.983261
38.605377
38.605377
38.605377
38.983261
38.605377
38.605377
NA
-2.500000
 
-2.099998
-1.599998
-2.000000
-2.000000
-2.000000
-1.799999
-2.099998
-2.200001
-2.299999
-2.299999
-2.500000
-2.000000
-2.200001
-1.500000
-2.200001
-1.299999
-1.000000
-1.799999
-0.799999
-1.500000
-1.700001
-1.599998
-2.400002
-1.599998
-2.099998
-2.599998
-2.099998
-2.400002
-1.500000
-0.799999
NA
QAM256
UNKNOWN
QAM256
QAM256
QAM256
QAM256
QAM256
QAM256
QAM256
QAM256
QAM256
QAM256
QAM256
QAM256
QAM256
QAM256
QAM256
QAM256
QAM256
QAM256
QAM256
QAM256
QAM256
QAM256
QAM256
QAM256
QAM256
QAM256
QAM256
QAM256
QAM256
QAM256
OFDM
IndexLock StatusFrequencySymbol RatePower LevelModulationChannel Type
Upstream
Channel Bonding Value
1
2
3
4
5
Locked
Not Locked
Locked
Locked
Not Locked
30300000
17300000
36700000
41200000
23700000
5120 KSym/sec
5120 KSym/sec
5120 KSym/sec
1280 KSym/sec
5120 KSym/sec
53.020599
53.270599
49.270599
51.250000
53.270599
64QAM
64QAM
64QAM
64QAM
64QAM
US_TYPE_ATDMA
US_TYPE_ATDMA
US_TYPE_ATDMA
US_TYPE_ATDMA
US_TYPE_ATDMA

 

Here's a representative PingPlotter screen shot: https://i.imgur.com/afDFofV.png

 

The incoming cable from the street is at 30 years old. I'm beginning to suspect it.

 

Comcast support (via the chat agent) found something and adjusted something once, but I'm not sure it made any difference.

 

I'd appreciate any insights about what to look for or try next.

 

 

Responses

EG

Expert

 • 

86K Messages

8 m ago

The upstream power is too high / out of spec. That can cause random disconnects, spontaneous re-booting of the modem, speed, packet loss, latency problems, and the un-bonding of channels.

In a self troubleshooting effort to try to obtain better connectivity / more wiggle room, check to see if there are there any excess/unneeded coax cable splitters in the line leading to the modem that can be eliminated/re-configured. Any splitters that remain should be high quality and cable rated for 5-1002 MHz, bi-directional, and no gold colored garbage types like GE, RadioShack, RCA, Philips, Leviton, Magnavox, and Rocketfish from big box stores like Home Depot, Lowes, Target, Wal-Mart etc. Splitters should be swapped with known to be good / new ones to test

If there aren't any unneeded splitters that can be eliminated and if your coax wiring setup can't be reconfigured so that there is a single two way splitter connected directly off of the drop from the street/pole with one port feeding the modem and the other port feeding the rest of the house/equipment with additional splits as needed, and you've checked all the wiring and fittings for integrity and tightness and refresh them by taking them apart then check for and clean off any corrosion / oxidation on the center wire and put them back together again, then perhaps it's best to book a tech visit to investigate and correct.

I am not a Comcast Employee.
I am a Customer Expert volunteering my time to help other customers here in the Forums.
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