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Fluctuating Speeds

Member

Fluctuating Speeds

For the past few days, my business class internet speed has been all over the spectrum. I have the Deluxe 75 package. Typically my speeds run around 9 megabytes a second, but now it fluctuates between 3 and 8 megabytes a second. Ive done the typically reboot of the modem, but still seems to be doing the same thing. I am at a loss as to what is going on. A similar thing happened a few months back and then the entire area lost internet for two days. I am not sure what to do or just keep waiting to see what happens.

37 REPLIES
Community Manager
Community Manager

Re: Fluctuating Speeds

Hello xodus2222,

 

The community would like to help but can you clarify few items for us?

 

1. How many device do you connect  to the IP-Gateway?

2. Did you add a new device to your network?

3. Do you run an onsite server? (mail,storage, etc)

 

 

Thank you

Member

Re: Fluctuating Speeds

Right now its connected to two computers.  I have not added a new device to the server.  I do not run an onsite server.  Everything is backed up via external drives but those are not connected to the gateway.

Community Manager
Community Manager

Re: Fluctuating Speeds

xodus2222,

 

Thank you for the information.

Based on your post and our tests (arp/lanpol/pkt) this appears to be an issue with the IP-Gateway.

I recommend a tech call to replace it.

 

You can either contact our technical support at 1-800-391-3000 or send me a private message with your contact information and I can set it for you.

 

Thank you 

Member

Re: Fluctuating Speeds

Its starting to get annoying.  Ive noticed that I have a good 86Mbps in the morning and starting around 11pm.  Around 9pm I bottom out at about 22MBPS and then sparadic up and down as the night goes on up until 11ish.  I did the ping thing but really do not understand this packet loss info that I see on a few of the tests I ran.  I just want my speeds back.  Its very annoying.

 

I did notice when I did the ping test, I had a packet loss from anywhere from 22% to 100% on the same, what looks like an ip address all from the same location.marietta ga comcast.net.  I dont know what that means or if that has anything to do with what is happening to my signal.

Trusted Forum Contributor

Re: Fluctuating Speeds

Head over to http://192.168.100.1 or http://10.0.0.1 and post the signal levels for your modem. Should be under the "Cable modem" page or "WAN status"(depending on gateway). 

Member

Re: Fluctuating Speeds

This is what I got. 

 

 

Downstream Channel

 

Downstream Frequency 716.999756 MHz     710.998535 MHz     723.001099 MHz     734.999023 MHz

 

Lock Status                      Locked                         Locked                               Locked             Locked

 

Modulation                      256 QAM                       256 QAM                          256 QAM               256 QAM

 

Symbol Rate                   5.360537Msym/sec 5.360537  Msym/sec 5.360537  Msym/sec 5.360537  Msym/sec

 

Downstream Power    -0.638958 dBmV         -0.630722 dBmV          0.312972 dBmV      1.197976 dBmV

 

SNR                                 37.935909 dB             37.935909 dB               37.935909 dB          38.257755 dB

 

 

Upstream Channel

 

Upstream Frequency         22799796 Hz        9599819 Hz                 36399659 Hz

 

Lock Status                                Locked              Locked                          Locked

 

Modulation                              64QAM                 64QAM                          64QAM

 

Symbol Rate                    5120 KSym/sec                  5120 KSym/sec        5120 KSym/sec

 

Upstream Power                45.5000 dBmV           46.2500 dBmV               46.7500 dBmV

 

Channel ID 4 5 6

 

 

Member

Re: Fluctuating Speeds

I am detecting a trend that occurs around 10pm.  Last night my internet dropped from 86.5 Mbps to 12 Mbps.  Around 11:15 pm it goes back up to around 80 Mbps.  I think a pattern is forming here.  I am not sure what is going on at that time of night to make it do this.

Trusted Forum Contributor

Re: Fluctuating Speeds

Were those levels grabbed when you had slow speeds? 

Member

Re: Fluctuating Speeds

It was not.  I can grab them when it happens again.  If I am right, it should happen about 10pm tonight.  I am starting to be able to time it right.  I will grab it when it happens later tonight.

Member

Re: Fluctuating Speeds

So during one of its moments last night, I captured this

 

Downstream Frequency              

716.998169 MHz               698.999023 MHz               705.000244 MHz               735.002075 MHz

 

Downstream Power      

0.811125 dBmV                1.298418 dBmV                0.686946 dBmV                2.525126 dBmV

Trusted Forum Contributor

Re: Fluctuating Speeds

The downstream looks good. We'll also want to see the upstream to ensure there are no issues there. 

Member

Re: Fluctuating Speeds

I try to capture it again when it happens.  Last night my speeds dropped from 86Mbps to 17Mbps for a short time and then bounced back up.  On my end, I can not find anything that would limit the traffic. 

Member

Re: Fluctuating Speeds

Well last night between 10 pm and 11:30 pm we had a download speed of 8Mbps.  My phone downloads faster.  Here is what I captured.

 

Downstream Channel

 

Downstream Frequency

 

717.001831 MHz                      722.998535 MHz               728.999878 MHz                  735.001099 MHz

 

Modulation

 

256 QAM                                             256 QAM                         256 QAM                             256 QAM

 

Symbol Rate

 

5.360537Msym/sec                     5.360537Msym/sec                 5.360537Msym/sec            5.360537Msym/sec

 

Downstream Power

 

1.194716 dBmV                                1.859393 dBmV                 1.889709 dBmV                    2.727943 dBmV

 

SNR

37.935909 dB                                  38.257755 dB                            38.257755 dB                 38.257755 dB

 

Upstream Channel

 

Upstream Frequency

 

22799829 Hz                                      29599750 Hz                          36399827 Hz

 

Modulation

 

64QAM                                                     64QAM                                    64QAM

 

Symbol Rate

 

5120 KSym/sec                                     5120 KSym/sec                   5120 KSym/sec

 

Upstream Power

 

44.2500 dBmV                         45.0000 dBmV                   45.2500 dBmV

 

Channel ID 4 5 6

Trusted Forum Contributor

Re: Fluctuating Speeds

Your signal levels look ok from what I can see. Have you had a tech out yet? At minimum it'd be good to have one out so we can check the line, run some test and possibly replace the modem. If possible I would schedule the tech visit for as late as posssible. It's unlikely they'll catch it in the act since it happens so late, but there is a chance the tech would be able to see something on the network changing as it turns night. 

Member

Re: Fluctuating Speeds

One is suppose to come tomorrow, but if its acting normal then how will they ever find out what the issue is.

Member

Re: Fluctuating Speeds

So the tech came out and did something out at the box in front of the building.  He said there were things that needed fixing.  He came in and put in a new outlet in the wall where the cable hooked up to.  I am on the 75 Deluxe package.  He made a comment that comcast guarantees up to 75 in the package but never a constant 75 Mbps.  Is that true?  My speed tests seem to be semi worse since he came and left.  I was at 75 when before he arrived and now I am around 61 Mbps.  I dont know if this is a sign of things to come or not.

Member

Re: Fluctuating Speeds

Ive now been told they can do nothing more for me. My speeds for the 75 Mbps is now averaging 35 Mbps.  I guess its either pay for something I cant have anymore or find a different service. I can't believe this is happening. 

Member

Re: Fluctuating Speeds

Is it possible this could be due to a bad modem/gateway? 

 

Another forum suggested changing the DNS but not sure about that. Thoughts?

Trusted Forum Contributor

Re: Fluctuating Speeds


xodus2222 wrote:

So the tech came out and did something out at the box in front of the building.  He said there were things that needed fixing.  He came in and put in a new outlet in the wall where the cable hooked up to.  I am on the 75 Deluxe package.  He made a comment that comcast guarantees up to 75 in the package but never a constant 75 Mbps.  Is that true?  My speed tests seem to be semi worse since he came and left.  I was at 75 when before he arrived and now I am around 61 Mbps.  I dont know if this is a sign of things to come or not.


Yes, this is true. No ISP guarantees bandwidth, they all say "up to". Though, you  can sure complain if you don't get the speed you are paying for. They'll try to use the "up to" agrument with you, but as long as your persistent they'll keep working with you. As for speed test, be sure to test a few servers and average the results.

 


xodus2222 wrote:

Is it possible this could be due to a bad modem/gateway? 

 

Another forum suggested changing the DNS but not sure about that. Thoughts?


Yes, it is very possible you have a bad modem, but it's hard to say. Generally the tech will replace them upon arriving. Though, I imagine since he found some issues at the tap he thought that'd clear it up. I wouldn't expect a DNS change to change your speeds, but if you aren't you should be using GoogleDNS.
You'll really just need to keeep pursuing Comcast on the speed issue. I'd recommend going through the 800 number again, having a tech out and getting his supervisors number. Give him a call and tell him your issue. He'll be able to troubelshoot a bit better since he directly works with your local network.
Member

Re: Fluctuating Speeds

Thanks for the response.  A second tech is coming tomorrow.  Ive never messed with the DNS but will try. Ive had only one issue in the last three years so this speed thing is troublesome. I dont want this to be the new norm.

Highlighted
Member

Re: Fluctuating Speeds

Is there anything else I need to say to the tech that might identify an issue.  I just have this feeling that he will replace my gateway and there will be no change.  It doesnt make sense that after three years of no issues that all of a sudden getting decent speeds is hard to get.  I just want to make sure I get everything I need out of the tech while he is here today.  I know the other tech did some things at the box outside but is there anything more they can do at this "box"?

KAT52HEY
New Member

Re: Fluctuating Speeds

TO xxodus2222 THANK YOU for posting this problem, I am having the exact same problem even the same dates you mentioned, I agree it is becoming very annoying. I've been use to having 5-6 tabs open at the same time as they all cross reference each other in my job I do.

Now I know to call and schedulee an appointment (fingers crossed). I am anxious to here how your appointment goes today.

Member

Re: Fluctuating Speeds

The appointment started a bit rough.  I was given precise information to tell the tech guy and he wasnt going to listen to it.  He checked my signal and said that he could not find anything wrong. I said that there was an issue with the upstream signal on my gateway and he said I was wrong and that it was ok.   I then told him to replace my modem and he was like well if there isnt anything wrong with your service then why would I replace your gateway.  I had even told him on the phone, twice, that I needed and wanted a new modem.  Finally, he gave in and replaced it.  Unfortunately, hours after he left, the speed fluctuations began again.  How do you fix an issue that no one else can find?  I talked to "comcast john" yesterday on the phone, who was wonderful to talk to.  He was extremely helpful and told me exactly what to say to the tech.  To be honest, I dont know where to go from here.  I was so fed up with it last night that I didnt even do any work.

Community Manager
Community Manager

Re: Fluctuating Speeds

xodus2222,

 

Sorry hear that your recent tech call was not able to address this issue.

Additionally we do apologize for the poor experience you had.

 

I've engaged our regional support team to assist with this issue.

If you have any question please send me a pm.

 

 

Thank you

Member

Re: Fluctuating Speeds

Thank you Jon.  Out of all of this, you have been the most helpful and kind.  I greatly appreciate it.

Member

Re: Fluctuating Speeds

The tier 2 tech is giong to monitor my modem signal as well as the node in the neighborhood to see if anything else is going on.  Fingers crossed.

Member

Re: Fluctuating Speeds

Well after 4 days of monitoring the gateway, they found no issues.  Over the weekend, the speeds only fluctuated twice that made it fall to around 50Mbps.  Last night, it did drop from 85 Mbps to 10 Mbps for a little bit, but if no one can find anything wrong then not sure what to do.  I guess I will just monitor it and see what happens.

Community Manager
Community Manager

Re: Fluctuating Speeds

xodus2222,

 

Thank you for sharing your experience and updates to this issue.

We appreciate it!

 

Did your service stabilize a bit more after the weekend test?

 

 

 

Thank you

Member

Re: Fluctuating Speeds

The weekend wasnt too bad.  The lowest low I saw was about 55.  However, the last few nights has seen it drop to about 15 to 20 Mbps over a span of a few hours. 

 

Is it possible that if I have two computers connected to the gateway that when I turn off one there is some sort of speed pull from one port that makes the port on the second pc slow down.  That probably doesnt even make sense, but I am sort of grasping here.

neteng404
New Member

Re: Fluctuating Speeds

Hello.

 

I am a comcast business customer in Fremont, CA and have been so for years with almost zero connectivity problems, until recently.

 

Now I have 2 serious problems, one is with the connection reliability and speed, the other is with the recently imposed speed cap.

 

Over the past month or so (7/2014 to now) I have been enduring numerous hard downs as well as significant and erratic speed decreases.  There has been an increased number of planned matinenance outages as well.  The frequency of these issues appears to be increasing and is becoming a serious issue for my business. First my speed dropped from about 30Mbps down to around 16Mbps down (around the same time the new Xfinity and business price/speed tiers were rolled out).  Speed and reliability has been steadily degrading for longer periods of time, with the worst performance coming in at 2Mbps down / 2Mbps up, typically in the 10PM - 6AM time period (my working hours) but also during other random times of the day.

 

My service plan has remained the same and over the years I was getting periodic calls from Comcast letting me know that if I reboot my modem I will see a speed increase.  This continued until I was getting about 32Mbps down and 5Mbps up (fantastic!) for at least a year.  The recent and sudden 50% drop in speed to ~16Mbps (obviously an intentional speed cap) is rather insulting considering I am still paying for the same plan + incremental fee increases over the years while now getting half of what I was getting before.  If I get less speed and less reliability, I should be charged comparably less and ideally, these problems should be resolved.

 

Can anyone explain to me why my speed dropped from 30+Mbps to 16Mbps?

 

Can anyone help with the connection speed and reliability issues?

 

Is anyone else having this issue in my area?

 

 

 

Cable Modem

Initilization Procedure

Initialize HardwareComplete
Acquire Downstream ChannelComplete
Upstream RangingComplete
DHCP BoundComplete
Set Time-of-DayComplete
Download CM Configuration FileComplete
RegistrationComplete
TRAFFIC ENABLED

Downstream Channel

Downstream Frequency591000000 Hz
Lock StatusLocked
Modulation256 QAM
Symbol Rate5.360537 Msym/sec
Downstream Power-0.7 dBmV
SNR31.705 dB

Upstream Channel

Upstream Frequency18900000 Hz
Lock StatusLocked
Modulation64QAM
Symbol Rate2560000 sym/sec
Upstream Power41.6 dBmV
Channel ID37

 

Thanks in adavance to anyone willing to take the time to provide any useful advice relevant to these problems.

 

--neteng404

Tags (1)
neteng404
New Member

Re: Fluctuating Speeds

** bump **
Trusted Forum Contributor

Re: Fluctuating Speeds

Be sure to always open your own thread neteng404. It will be sure people see it and click on it. Personally I stopped reading this thread once a majority of the troubleshooting was over. 

 

As for your cable modem stats. Are you able to post the full ouput? Preferably when the connection is working fine and when it is acting up. 

Member

Re: Fluctuating Speeds

I wish troubleshooting and found a solution..so far its still a no go.

Member

Re: Fluctuating Speeds

Its now been 3 months since I have been dealing with this fluctuating speed issue. To summarize:

 

Ive had 2 techs to visit.

Ive had my gateway replaced.

I had the outlet replaced.

I had the nodes checked out front.

I was told that there was no heavy usage in my area so there shouldn’t be a slow down.

I had my gateway monitored for a series of days without any issues found.

Talked to several tier 2 people.

 

However, my speeds continue to fluctuate between 5Mbps and 86 Mbps. Last night I dropped down to a nice 5 Mbps. I could do my work faster off my phone than the pc. I do not know what else there is to do, except to either not renew my contract, which expires in the next week or move or not work at all during certain times, which isn’t very productive. I am totally at a loss here.

Member

Re: Fluctuating Speeds

Anyone?

Community Manager
Community Manager

Re: Fluctuating Speeds

xodus2222,

 

Good conversing with you once again through the private messages.

As for the troubleshooting as we discuss isolating your network device will determine what could be causing "timed" degradation.

 

Please post again when you can.

 

Thank you

Community Manager
Community Manager

Re: Fluctuating Speeds

xodus2222,

 

Good conversing with you once again through the private messages.

As for the troubleshooting as we discuss isolating your network device will determine what could be causing "timed" degradation.

 

Please post again when you can.

 

Thank you

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