30 Mbps and having trouble streaming Netflix

BlitzkriegBart

Honorable
Sep 10, 2012
7
0
10,510
Hello,

I have been having intermittent trouble streaming Netflix for a while now. I've had my cable company out to troubleshoot a few times over the summer. They have replaced hardware and recently upgraded me from 15 down to 30 down. Either way it only works well about every other day with some good weeks and some bad.

A lot of the time speed test results come back at full speed but sometimes they are even as low as ~1 down. Sometimes speedtest.net can't even connect or can't complete it's test.

I wired my house so I am trying to stream (and speed test) with a wired connection (laptop or PS3).

Is this something I should keep having my cable company try to fix or are my expectations too high?
 
Solution
It's possible that upstream levels in the 40s are normal for an Arris, I'm not up on them, but if they use anything similar to what Motorola uses for a transmitter then it is too high (Moto's max at 52dB). Around here Cox aims for 32-35dB upstream.
If you have a Motorola modem bring up 192.168.100.1 in your browser and choose the 'signal' tab. This is an internal page on the modem that will show your signal strength. You want to see 0 or better for downstream, and mid 30's for upstream. If you see anything 45 or higher then your modem is having to shout to be heard and it's time to have the cable company investigate.
 

BlitzkriegBart

Honorable
Sep 10, 2012
7
0
10,510

When they upgraded my speed to 30 Mbps down and 3 up they switched my Surfboard 6120 out for an Arris Modem/Router combo. I think I found something analogous to what you are talking about though. In the admin software for this Arris box there is a tab labeled "HSD".

This is what it says under "RF Parameters" in that screen.

RF Parameters
Downstream
Interface Name .. Freq ................ Power ............. SNR .......... Modulation
Downstream 1 ... 681.000 MHz .. -3.20 dBmV .... 38.90 dB ... QAM256
Downstream 2 ... 663.000 MHz .. -4.20 dBmV .... 39.00 dB ... QAM256
Downstream 3 ... 669.000 MHz .. -3.50 dBmV .... 39.40 dB ... QAM256
Downstream 4 ... 675.000 MHz .. -3.50 dBmV .... 39.40 dB ... QAM256
Downstream 5 ... 639.000 MHz .. -3.50 dBmV .... 39.40 dB ... QAM256
Downstream 6 ... 645.000 MHz .. -3.70 dBmV .... 39.30 dB ... QAM256
Downstream 7 ... 651.000 MHz .. -4.10 dBmV .... 39.20 dB ... QAM256
Downstream 8 ... 657.000 MHz .. -4.40 dBmV .... 38.60 dB ... QAM256
Upstream
Interface Name .. Frequency ...... Power ....... Channel type .. Symbol Rate .. Modulation
Upstream 1 ....... 33.60 MHz ..... 43.50 dBmV .. ATDMA ....... 2560 kSym/s .. QAM64
Upstream 2 ....... 37.60 MHz ..... 43.40 dBmV .. TDMA ......... 2560 kSym/s .. QAM16
Upstream 3 ---
Upstream 4

I just ran a speed test with my laptop connected to the Arris box and Wifi turned off and I am getting < 1 Mbps down. :whistle:
 
Downstream look OK (close to 0). However, upstream is terrible. It should be ~10dB lower than what is shown. That's likely the source of your problem.

There are many things that could cause this situation:

Too many/wrong type splitters
Reversed splitters
Pinched/crimped coax
Staples in coax (happens when construction dweebs go crazy with a nail gun)
Badly installed fittings
Cable system problem.

Cable company really needs to check it out.
 

BlitzkriegBart

Honorable
Sep 10, 2012
7
0
10,510


Thanks for your input. I called them again and they have someone coming out here (again) on Thursday.

I did some reading on those numbers. According to this Upstream power levels in the 40s are normal. (http://homepage.ntlworld.com/robin.d.h.walker/cmtips/signal.html)

I dumped their Digital Cable TV service a while back because I was having intermittent problems with signal loss, so I have a tv filter on my line. They have replaced that a few times. Could that be a cause? Should I try to get them to remove that?

I'm guessing the same thing that caused HD tv to be spotty is causing my internet to be spotty, so that filter is probably a non factor.
 
It's possible that upstream levels in the 40s are normal for an Arris, I'm not up on them, but if they use anything similar to what Motorola uses for a transmitter then it is too high (Moto's max at 52dB). Around here Cox aims for 32-35dB upstream.
 
Solution

BlitzkriegBart

Honorable
Sep 10, 2012
7
0
10,510
My speed is really solid right now and my power levels are different so I am recording them.


Interface Name .. Freq ................ Power .......... SNR ........... Modulation
Downstream 1 ... 681.000 MHz .. -1.90 dBmV .. 39.00 dB ... QAM256
Downstream 2 ... 663.000 MHz .. -2.70 dBmV .. 39.40 dB ... QAM256
Downstream 3 ... 669.000 MHz .. -2.20 dBmV .. 39.60 dB ... QAM256
Downstream 4 ... 675.000 MHz .. -2.20 dBmV .. 39.50 dB ... QAM256
Downstream 5 ... 639.000 MHz .. -2.00 dBmV .. 39.50 dB ... QAM256
Downstream 6 ... 645.000 MHz .. -2.30 dBmV .. 39.40 dB ... QAM256
Downstream 7 ... 651.000 MHz .. -2.80 dBmV .. 39.30 dB ... QAM256
Downstream 8 ... 657.000 MHz .. -3.10 dBmV .. 39.10 dB ... QAM256

Upstream
Interface Name .. Frequency ..... Power ............ Channel type ... Symbol Rate ... Modulation
Upstream 1 ........ 33.60 MHz .... 43.20 dBmV .. ATDMA ............ 2560 kSym/s .. QAM64
Upstream 2 ........ 37.60 MHz .... 43.10 dBmV .. TDMA .............. 2560 kSym/s .. QAM16
Upstream 3
Upstream 4