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XFinity speed slows down...modem restart fixes it...slows down again...restart fixes it again...etc

Regular Visitor

XFinity speed slows down...modem restart fixes it...slows down again...restart fixes it again...etc

Hi Everyone,

 

So I have a weird issue with my XFinity internet. I am currently on the Performance Plus w/Speed Increase (additional $15 per month) about ~ 150Mbps/5Mbps package. My modem is an Arris SB6183 with firmware D30CM-OSPREY-2.4.0.0-GA-03-NOSH.

 

My setup consists of the modem and my laptop plugged straight into the back of the modem via ethernet cord. No routers...no WiFi...no other devices...just my laptop.

 

My speed drops to about 50 Mbps down every day. I restart the modem, and the speed shoots up to 200 Mbps (which is awesome...) but this only lasts about 10-15 minutes. After 10-15 minutes, the speed drops down to about 50 Mbps again. 

 

I called the Tech folks, they recommended to get another modem. So I did... TWO of them:  Netgear CM500 and Arris SB6190. The issue remains:  fast connection when modem starts...slow connection after about 15 minutes. 

 

I live in an apartment complex that was built around 2003-2004. I don't have access to any coaxial wiring (I looked in the obvious closets or electrical panel...but nothing there). I have one coaxial port in the living room and one in the bedroom. Using either one of them has the same effect.

 

If you look at my signal levels below, you will see that the Downstream Bonded channels are on the margin (~ -9dBm) After reading about this, I think ISP want the levels to be -5 dBm to + 5dBm...correct  ? 

 

But the same signals levels are present when I have the fast connection or slow connection. Also, this happens at 3AM when everyone is asleep or Saturday afternoon when the entire apartment complex is streaming movies:

 

1 Locked QAM256 25 669000000 Hz -8.8 dBmV 39.4 dB 0 0
2 Locked QAM256 26 675000000 Hz -9.3 dBmV 38.4 dB 0 0
3 Locked QAM256 27 681000000 Hz -8.8 dBmV 39.4 dB 0 0
4 Locked QAM256 28 687000000 Hz -8.1 dBmV 39.6 dB 0 0
5 Locked QAM256 29 693000000 Hz -8.8 dBmV 39.2 dB 0 0
6 Locked QAM256 30 699000000 Hz -8.5 dBmV 39.5 dB 0 0
7 Locked QAM256 31 705000000 Hz -7.5 dBmV 39.9 dB 0 0
8 Locked QAM256 32 711000000 Hz -8.3 dBmV 39.6 dB 0 0
9 Locked QAM256 33 717000000 Hz -7.8 dBmV 39.7 dB 0 0
10 Locked QAM256 34 723000000 Hz -7.3 dBmV 39.9 dB 0 0
11 Locked QAM256 35 729000000 Hz -7.5 dBmV 37.8 dB 13 0
12 Locked QAM256 36 735000000 Hz -7.1 dBmV 36.8 dB 42 0
13 Locked QAM256 37 741000000 Hz -7.6 dBmV 36.7 dB 0 0
14 Locked QAM256 38 747000000 Hz -7.2 dBmV 35.9 dB 1274 0
15 Locked QAM256 39 753000000 Hz -6.8 dBmV 34.3 dB 417623 751076
16 Locked QAM256 40 759000000 Hz -8.0 dBmV 39.7 dB 0 0

 

 
Upstream Bonded Channels
Channel Lock Status US Channel Type Channel ID Symbol Rate Frequency Power
1 Locked ATDMA 3 5120 Ksym/sec 23700000 Hz 47.5 dBmV
2 Locked ATDMA 1 5120 Ksym/sec 36500000 Hz 47.5 dBmV
3 Locked ATDMA 2 5120 Ksym/sec 30100000 Hz 47.5 dBmV
4 Locked ATDMA 4 5120 Ksym/sec 17300000 Hz 47.5 dBmV

 

Screenshots below:

 

fast_speed.pngfast_Stats.pngslow_speed.pngslow_Stats.png

 

It is almost as if a throttling is activated ... since the slow down happens fairly consitently after about 10-15 minutes of the modem being on. Any suggestions or info would be much appreciated. Should a tech come out to teh apartment ? Thanks kindly!

 

Regular Visitor

Re: XFinity speed slows down...modem restart fixes it...slows down again...restart fixes it again...

Here are the speed tests 20 minutes after modem reboot for the Tech who refused to believe me. Tests run about 5:10PM local time (MDT)

 

https://www.speedtest.net/result/8639548690
https://www.speedtest.net/result/8639550765
https://www.speedtest.net/result/8639552658

 

Regular Visitor

Re: XFinity speed slows down...modem restart fixes it...slows down again...restart fixes it again...

Technician came out this morning. Issue seems to be fixed. Tech found some loose connection in the splitter feeding my apartment unit's bedroom and living room...and he also mentioned something else he replaced (can't remember what). 

 

Now I just need to figure out why Comcast says I used 3x more Data than I normally do...