Internet speed test reliability

[mike-a1]

I have noticed a major slow down in the upload/download speeds recently and decided to runa few speed tests.

I used 2 different test sites -

xfinity (twice) -

test 1 download 4.0 and upload 1.8

test 2 download 4.7 upload 0.7

speedcheck (three times)

test a - download 1.86 upload 1.3

test b - download 2.16 upload 2.68

test c - download 2.07 upload 2.19

I am on the performnace starter plan advertized at up to 25Mbps 

I restarted the router 2 times in hopes of fixing what I think is very  ery slow speeds.

Are the speed tests at any sites reliable enough to determine if the router is working properly?

[EG]

Is this with a WiFi connection ? If so, for a test, does a computer hardwired directly to the router / gateway device with an ethernet cable have the same problem ?

[mike-a1]

Yes, it is a wi-fi connection that I tested.

[mike-a1]

Good point regarding testing as a hardwired device instead of wi-fi connected. I will check that out and get back to you in a few minutes.

[mike-a1]

Tested just via cable and wi-fi turned off.

Speed results - Download 2.6, upload 1.7 

Not looking good - The response from the support person I talked to was that I needed to buy a better plan. The performance starter with "up to 25 Mbps" wasn't going to be good enough - they said.  Sorry, but I don'y buy that because these speed test numbers aren't even close to what they should be.

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[mike-a1]

Retested again today - results as follows

26.9 download, 2.1 upload (this morning)

25.4 download, 2.2 upload (tonight)

Didn't do much other than reboot the modem again 

Checked using my laptop wired into the modem via ethernet and also using wi-fi

28.4 download, and 2.0 upload

Not sure what caused the impressive increase in download speed, but perhaps a miracle??

[EG]

What do the modem's signal stats look like ? Try getting them here http://192.168.100.1 or here http://10.0.0.1

Please post the *Downstream Power Level*, the *Upstream Power Level*, and the *SNR* (Signal to Noise Ratio) numbers.

What is the exact make and model number of the modem ?

[mike-a1]

Thanks - the first url is not working and the second one won't recognize my user id when I type it in and try to login.

the make and model of the modem is an xfinity dual band Wifi 802.11ac  XB3

[EG]

The default username is admin and the default password is password

[mike-a1]

thanks for the tip on the user and password - got it to work

So - results for Gateway Model DPC3941T modem were

downstream power level -3dBmV, modulation 256QAM, SNR 40.3 to 40.9

upstream power level 57.000 dBmV, modulation 64QAM, and Frequency 0MHz

[EG]

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

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.

[mike-a1]

okay - so I pulled a couple ceiling panels and verified that the cable drop goes into a single splitter provided at the time of installation - only one wire out that goes directly into the cable modem.

re-checked the speed test again - download 13.1 and upload 2.1 (ethernet connected)

and download 7.1, up load 1.9 (wi-fi connected)

re-checked the down stream and up stream numbers - up stream (no change from previous test) and down stream power level went from -3 to 0.1 to 0.5 depending on channel

thanks for your interest and advice

[EG]

O/k thn re-visit my last comment. Bear in mind that if the premises facing techs can not find or fix a problem at your home, it is they who are responsible for escalating it to their line / network / maintenance dept. techs. The problem may lie beyond your home in the local neighborhood infrastructure somewhere but it is their S.O.P. to start at the home.