Customer Provided Modems Will Not Get Gig Speeds on Xfinity Plans

[omarvilla59]

Quick Poll. Please reply if you are only getting 1/3 or less of the gig speed advertised using your own modem on the gig plan with Xfinity/Comcast. Also, if you are getting more than half the speed using your own equiptment, tell us what your setup is. Thank you. 

[Skytrooper]

I got the Comcast Modem and it dont get gig speeds either. Always about 1/3 of a gig. Maybe because of high usage because of virus. I would sometimes get in the 900 range before this. 

Interested to see if you get higher speeds when this thing is over. My 2 year contract is running out and I am interested in getting my own modem again. Tired of their box and modem rental fees.

[omarvilla59]

Same here. I activated three different Arris SB8200 that I purchased and was still getting less than 1/3 of the speeds. I decided to rent thier gig modem to see if it would improve which it did for one day (500mbps) and then it went back to around 150mbps. Gonna drop my plan down to the blast speed which it did better when I had it even during the pandemic. I believe comcast is throttling down customers with the gig plans during this pandemic to even out the bandwith until this is over. When I was on on the blast plan I was actually getting more than the speeds advertised during the pandemic. 

[gawgt]

Arris T25 modem connected to Netgear R6400 router.  946.4 down, 40.5 up.

[mkarpo]

Bought both a Netgear CM1000V2 and Arris SB8200. Both top out around 350mbps.
Lots of T3/T4 errors on the logs. Did all the indoor troubleshooting recommendations.
Had a line tech come out to check from the pole to my exterior box and said it was fine. They can't enter home still in my area...

[ChrisSoflo]

Just upgraded my plan to 1GB and had to buy the SB8200. I'm getting 750mbps download and 38 on the upload with it wired via an ethernet cable. I've seen no increase on my wifi speeds from making the change.

[spongebob2004]

CM1000 >Netgear RAX200>iMac.  

Constant 930-940  down and  40 up

[ChrisSoflo]

@spongebob2004 Are you connected over wifi or ethernet cable? Also how do you like that router?

[spongebob2004]

Speed test shown are from hardwired iMac desktop. The RAX200 tri-band router is awesome. Performance wise, a beast! No complaints at all!

[kvjkhjkhdfghjdf]

spongebob - I have a CM1000V2 that I just bought and I'm getting 2/3 of my plan speed. Getting 200 mbps downstream. My OFDM SNR is 30-31. Would you mind sharing your basic/cable-connection pages with levels so I can see what your SNR and power levels are as comparison??  I suspect my downstream OFDM signal/noise ratio is too low.  Here are mine:

Frequency start Value

This field below allows you to modify the frequency the cable modem start with its scan during initialization and registration. Enter the new start frequency and restart the cable modem for it to take effect.

Starting Frequency

<tabindex=-1>Startup Procedure</tabindex=-1>

Procedure Status Comment Acquire Downstream Channel 579000000 Hz Locked Connectivity State OK Operational Boot State OK Operational Security Enable BPI+ IP Provisioning Mode Honor MDD IPv6 only

<tabindex=-1>Downstream Bonded Channels</tabindex=-1>

Channel Lock Status Modulation Channel ID Frequency Power SNR / MER Unerrored Codewords Correctable Codewords Uncorrectable Codewords 1 Locked QAM256 13 579000000 Hz 0.9 dBmV 38.0 dB 935278271 0 0 2 Locked QAM256 10 561000000 Hz 1.4 dBmV 38.2 dB 934374163 0 0 3 Locked QAM256 11 567000000 Hz 1.3 dBmV 38.1 dB 934378985 0 0 4 Locked QAM256 12 573000000 Hz 1.3 dBmV 38.1 dB 934392638 0 0 5 Locked QAM256 14 585000000 Hz 1.0 dBmV 37.9 dB 934396965 0 0 6 Locked QAM256 15 591000000 Hz 0.9 dBmV 38.0 dB 934400171 0 0 7 Locked QAM256 16 597000000 Hz 0.3 dBmV 37.7 dB 934403492 0 0 8 Locked QAM256 17 603000000 Hz -0.1 dBmV 37.6 dB 934408529 0 0 9 Locked QAM256 18 609000000 Hz -0.4 dBmV 37.3 dB 934418548 0 0 10 Locked QAM256 19 633000000 Hz 1.0 dBmV 37.2 dB 934422572 13 19 11 Locked QAM256 20 615000000 Hz -0.5 dBmV 37.2 dB 934427824 0 0 12 Locked QAM256 21 621000000 Hz -0.2 dBmV 37.2 dB 934430138 0 0 13 Locked QAM256 22 627000000 Hz 1.0 dBmV 37.4 dB 934433982 0 0 14 Locked QAM256 23 639000000 Hz 1.7 dBmV 37.3 dB 934416907 3 31 15 Locked QAM256 24 645000000 Hz 1.0 dBmV 37.1 dB 934416298 6 28 16 Locked QAM256 26 651000000 Hz 0.9 dBmV 36.9 dB 934411904 7 28 17 Locked QAM256 27 657000000 Hz 0.1 dBmV 36.6 dB 934437070 12 28 18 Locked QAM256 28 663000000 Hz -0.3 dBmV 36.4 dB 934440663 8 31 19 Locked QAM256 29 669000000 Hz 0.0 dBmV 36.3 dB 934443081 10 30 20 Locked QAM256 30 675000000 Hz 0.0 dBmV 35.8 dB 934447450 12 28 21 Locked QAM256 31 681000000 Hz 0.6 dBmV 35.9 dB 934450235 11 30 22 Locked QAM256 32 687000000 Hz 1.1 dBmV 36.0 dB 934456128 10 28 23 Locked QAM256 33 693000000 Hz 2.1 dBmV 35.9 dB 934458046 14 26 24 Locked QAM256 34 699000000 Hz 2.9 dBmV 36.1 dB 934462333 7 26 25 Locked QAM256 35 705000000 Hz 3.7 dBmV 36.3 dB 934466164 0 0 26 Locked QAM256 36 711000000 Hz 3.7 dBmV 36.3 dB 934469215 0 0 27 Locked QAM256 37 717000000 Hz 2.6 dBmV 36.0 dB 934473953 0 0 28 Locked QAM256 38 723000000 Hz 2.5 dBmV 36.1 dB 934476221 0 0 29 Locked QAM256 39 729000000 Hz 2.0 dBmV 35.9 dB 934482174 0 0 30 Locked QAM256 40 735000000 Hz 2.4 dBmV 35.8 dB 934483574 0 0 31 Locked QAM256 41 741000000 Hz 2.4 dBmV 35.6 dB 934486595 0 0 32 Not Locked Unknown 0 0 Hz 0.0 dBmV 0.0 dB 0 0 0

<tabindex=-1>Upstream Bonded Channels</tabindex=-1>

Channel Lock Status Modulation Channel ID Frequency Power 1 Locked ATDMA 81 36500000 Hz 45.5 dBmV 2 Locked ATDMA 82 30100000 Hz 45.5 dBmV 3 Locked ATDMA 83 23700000 Hz 44.0 dBmV 4 Not Locked Unknown 0 0 Hz 0.0 dBmV 5 Not Locked Unknown 0 0 Hz 0.0 dBmV 6 Not Locked Unknown 0 0 Hz 0.0 dBmV 7 Not Locked Unknown 0 0 Hz 0.0 dBmV 8 Not Locked Unknown 0 0 Hz 0.0 dBmV

<tabindex=-1>Downstream OFDM Channels</tabindex=-1>

Channel Lock Status Modulation / Profile ID Channel ID Frequency Power SNR / MER Active Subcarrier Number Range Unerrored Codewords Correctable Codewords Uncorrectable Codewords 1 Locked 0, 1, 2, 3 25 780000000 Hz 2.4 dBmV 30.8 dB 1108 ~ 2987 620682439 575471180 5054 2 Not Locked 0 0 0 Hz 6.6 dBmV 0.0 dB 0 ~ 4095 0 0 0

<tabindex=-1>Upstream OFDMA Channels</tabindex=-1>

Channel Lock Status Modulation / Profile ID Channel ID Frequency Power 1 Not Locked Unknown 0 0 Hz 0 dBmV 2 Not Locked Unknown 0 0 Hz 0 dBmV

Current System Time: Mon May 18 22:08:32 2020

System Up Time: 31:58:3

[CooyonLA]

I pay for gigabit speeds and get 95mbps at best. Comcast doesn't deliver a desirable service and could care less about its customers. Especially in areas where competition is non-existent.

[emaurice]

I have a Arris T25.  I get great speed (down>930 Mbps, up>37 Mbps) but periodic outage, see https://forums.xfinity.com/t5/Your-Home-Network/SIP-DNS-Query-Failure-Periodic-loss-of-Internet-Manu...

Screenshot

[spongebob2004]

How long has this been? Have you contacted support? Probably need to tweak a few settings. There is very little information to go on.... your equipment, are you connected via Ethernet cable or wi-fi? Have you power cycled your equipment? Try that first...I would connect support and have them assist with getting you up to speed.

[PCurrao]

[Edited original response stating top speeds of ~600]

Well, I have no idea what changed, or what happened out in the universe, but wired speeds are now showing 890-920mbps (on the Xfinity speed test site)

My previous tests were on Xfinity's site (the 500-600 speeds) but they are solid now. Other speed tests sites still show anywhere from 450-650, but I know that Xfinity won't back results from those sites, so that's not a battle I am going to fight.

I guess I can just be happy now that Xfinity's site is showing the correct speeds. Now I can sleep 🙂

[spongebob2004]

What does Support say?
Xfinity Support! A little help over here would be nice.

Thanks

[Masz]

Since I've always had daily issues with Comcast, I decided just to spend as much money as I could so surely I'd stop having daily issues, right?  I was informed that the cost of fiber-optic installation was about $500 for my area, etc - No matter, I decided whatever it takes;  I've had this service for about a year now (estimate).  So I sit here with my laptop wired to a Netgear CM1000 trying to get my internet going again and just ran a speed test:  246.0 Mbps download, 40.7 Mbps upload, Latency = 18ms (whatever that means)...  I'd say this is lackluster, especially since my internet service cuts out 13-18 times per week, and my TV loses signal and/or the image gets all blocky with no sound or distorted high-frequency sound.  Awesome!!  I think I'll purchase the CM1200 next...  Interestingly for the service calls, nothing has been wrong inside my home - the technician told me the signal was way to high outside, and gave the analogy of someone screaming into my ear vs talking at a correct level so I could understand... And Comcast charged me a fee for inside my home even though nothing was done there >> any they refused to reimburse the charge.  Yes, directly stealing from me.  I pay well each month.  Sometimes I'm very upset and do not want to pay, but... I suppose I'm a prisoner.  Thank you Comcast.  You are terrible.

[honestbridge]

I realize your posts is awhile back but I second that! I pay for 1GB and xfinity wants to blame my average 250mbs on my modem. I have the DOCSIS NETGEAR Modem CM1000 which is more than capable of providing the speeds. 

[EG]

7 month old dead thread now being closed.