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Inability to achieve Gigabit Speeds

Regular Visitor

Inability to achieve Gigabit Speeds

Good Evening

 

I have been experiencing an inability to achieve gigabit speeds as well as 4-5 disconnects or more per day for a period of almost six months where before I was not. I have had four technicians visit the home to check the drop and the home wiring, had the modem replaced 3 times and 2 RTM tickets have been filed. I have run speed tests across fast.com, DSL reports, xfinity speed test, and sourceforge with an average of anywhere between 200-250 Mbps and 550 Mbps down and 40 Mbps up with the Xfinity test being the outlier. This Xfinity speed is only achieved while running via IPV4 in the advanced settings.

 

This has been verified to occur across 3 different PCs with verifiable 10/100/1000 and even 10 gig NICs, direct connection to the XB6, 2 different routers (Netgear Orbi and Ubiquiti AmpliFi HD),  a purchased Comcast approved modem for comparison ( Netgear CM1000 which achieved even *lower* speeds and was returned) and 2 sets of patch cables both CAT5e and CAT6.

 

Upon reporting this information during the latest visit the "supervisor" connects the modem to his laptop and received 750 Mbps and insinuates that my equipment is the issue but that an RTM ticket will be opened and I'll be contacted once it is completed.

 

My hardware cannot possibly be the issue as I have gone through every conceivable part that could have been either not up to par or failed.

 

My XB6 reports the following for downstream and upstream data: 

 

Downstream
Channel Bonding Value
Index
30
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
32
 
Lock Status
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
Not Locked
Frequency
663000000
 
477000000
483000000
489000000
495000000
507000000
513000000
519000000
525000000
531000000
537000000
543000000
555000000
561000000
567000000
573000000
579000000
585000000
591000000
597000000
603000000
609000000
615000000
621000000
627000000
633000000
639000000
645000000
651000000
657000000
669000000
0
SNR
40.366287
 
40.946209
40.946209
40.366287
40.366287
40.946209
40.946209
40.366287
40.366287
40.946209
40.946209
40.946209
40.366287
40.366287
40.366287
40.946209
40.946209
40.366287
40.366287
40.946209
40.366287
40.366287
40.366287
40.366287
40.366287
40.366287
40.366287
40.366287
40.366287
40.946209
40.946209
NA
Power Level
13.199997
 
13.099998
13.300003
13.099998
13.199997
13.199997
13.300003
13.400002
13.300003
13.300003
13.300003
13.300003
13.400002
13.400002
13.599998
13.099998
13.300003
13.199997
13.000000
13.099998
13.199997
12.800003
12.599998
12.699997
12.699997
12.699997
13.000000
13.400002
13.400002
13.599998
12.599998
NA
Modulation
QAM256
UNSUPPORTED
QAM256
QAM256
QAM256
Upstream
Channel Bonding Value
Index
1
2
3
4
Lock Status
ACTIVE
ACTIVE
ACTIVE
ACTIVE
Frequency
16600000
23000000
29400000
35800000
Symbol Rate
5120 KSym/sec
5120 KSym/sec
5120 KSym/sec
5120 KSym/sec
Power Level
41.520599
41.020599
41.520599
41.270599
Modulation
64QAM
64QAM
64QAM
64QAM
Channel Type
US_TYPE_STDMA
US_TYPE_STDMA
US_TYPE_STDMA
US_TYPE_STDMA

 

I'm tired of being stuck in a loop with people assuming I don't understand what is being said to me or what controls the performance of my connection. I'm tired of paying $125 a month for 1Gbps service, $50 a month for the *privelege* of unlimited data, and receiving half, if that, of the speeds that I pay for and having 20-30 minutes a day of downtime. To say that I'm exasperated would be a complete understatement. 

 
 
Please Help
 
Thank You

 

Expert

Re: Inability to achieve Gigabit Speeds

Check your devices and make sure they are operating at 1Gbps Full Duplex.

Your downstream levels look a bit on the high side but I don’t think they’re high enough to cause an issue.

I have also escalated your issue to a Comcast Employee.

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Expert

Re: Inability to achieve Gigabit Speeds

This might help: https://forums.xfinity.com/t5/Your-Home-Network/Troubleshooting-Gigabit-internet-speeds/td-p/3145413...


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I am a Customer Expert volunteering my time to help other customers here in the Forums.
We ask that you post publicly so people with similar questions may benefit from the conversation.
Was your question answered? Mark the post as Best Answer!
Regular Visitor

Re: Inability to achieve Gigabit Speeds

Thanks for the prompt response.

 

I've gone through all the listed troubleshooting steps to no avail so far. However, I *did* disable IPv6 on both my NIC as well as router, and ran the command via Super User from this post: (https://forums.xfinity.com/t5/Internet-Archive/Gigabit-internet-slowness-Cable-modems-signals-and-co...).

 

Upon making those changes I am now seeing the following results:  

http://www.dslreports.com/speedtest/45565961 

https://www.speedtest.net/result/8011957873

610 Mbps down/ 41 up @ Fast.com

 

The average results are still well short of where they should be, but they are coming more into line with what the technician saw with their laptop.

Highlighted
Expert

Re: Inability to achieve Gigabit Speeds

The techs should be testing speeds with a device designed specifically to test gigabit speeds.  Testing with a laptop is not sufficient.  Hopefully, the employee that responds to your issue will be able to get the right people out there to get this fixed for you. 


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I am a Customer Expert volunteering my time to help other customers here in the Forums.
We ask that you post publicly so people with similar questions may benefit from the conversation.
Was your question answered? Mark the post as Best Answer!
Official Employee

Re: Inability to achieve Gigabit Speeds

Hi, senorfusion686. Welcome and thank you for posting! It does look like are some signal level issues taking place at your premise still. I understand that you've already had a few technician visits up to this point. I would like to look further into this for you and help you determine what options we have to get this corrected for you so you can move forward. To start, please send me a private message with your name and we will go from there. 

 


To send a private message, please click my name "ComcastMorgan" then select "Send a Message" on the right side.
 

Thank you.


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New Poster

Re: Inability to achieve Gigabit Speeds

I have the EXACT same problem. It’s funny that I have purchased a new modem (same as OP) and gone through both of the exact same WiFi setups plus a Netgear NighyHawk in my never ending attempt to get even half of what I’m supposed to get. I average 200-300 max but pay for 1GB. The fastest I have ever tested is 550Mbs but the service tech gets 880-900 with his little tester and says there is nothing he can do. I’m ready to call it quits and drop to a 400Mbs plan that will still be twice what I can actual see over WiFi. I think 1GB speeds is a myth.