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TheHeeyyy
join:2011-12-14
North York, ON

TheHeeyyy

Member

[Cable] Internet Sporadically Disconnects

I have Teksavvy cable internet, and live near Yonge and Steeles. Over the last few weeks I have noticed that the internet sporadically disconnects (as much as five times per day). My modem is a DCM475, and whenever the internet disconnects the same light pattern can be seen on the modem. The downstream LED will blink for a while before going solid, then the upstream LED will blink for a while. Eventually the upstream LED will go solid and the internet will reconnect, but that light pattern will usually cycle a few times before that occurs. Usually the internet will return in less than five minutes, but it has been disconnected for as long as half an hour. What I find very strange is that I am unable to access the modem's diagnostic page when the internet goes out. Is that normal?
kanatamike
join:2013-07-19
Kanata, ON

kanatamike

Member

I'm also having periodic disconnects. We don't notice it every day, but when we do notice it, it's always in the evenings. It's happening tonight. The internet connection will disappear for 30-60 seconds (near 100% packet loss) and then come back. Some nights are worse than others and some nights it doesn't happen at all. This has been going on for about three weeks.

My modem is in the basement, so I can't see the light pattern at the time the internet goes out, but I don't think mine changes as it wouldn't be able to reconnect in the time that it takes me to get to the basement.

Teksavvy is not providing any reasonable suggestions for troubleshooting. They want me to connect directly to the modem. That's not a problem, but then what? Do I sit there staring at the screen for hours or days until the problem starts happening again? And tell everyone in the house the can't use the internet for that time period?

I'm thinking I'll be cancelling my service over this problem if Teksavvy can't fix it.
jdrom
join:2008-03-02
East York, ON

jdrom to TheHeeyyy

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to TheHeeyyy
I get this from time to time too. If you look at the modem diagnostic page, do you see (Partial service) beside Return Path? That's usually what I see, and them the modem gets full sync within a minute or so and all is back to normal.

I've attributed it to Rogers doing work on the lines. For example, I cancelled my Home Phone service with them just this week. When my number ported over, my Internet dropped shortly after. I'm guessing they sent out a signal to disable my Home Phone modem that also knocked out my TekSavvy modem.
Solian
join:2013-09-05
canada

Solian to TheHeeyyy

Member

to TheHeeyyy
The toronto area has been having quite a few issues with cable internet from what I've been told.

Normally when the DS starts flashing on the modem, that means the signal was lost entrely and your cable
modem is now trying to reacquire its channels. When the US is flashing, the modem has found the downstream
channels it needs and is now working on your upstream channels. When the Online light is flashing, that means
your modem finally has the signals where they should be and its going to make an attempt at establishing
a connection (this is where your modem gets an IP address from the servers down the road).

In your case specifically, it looks like your modem lost its signal for a split second, and has to reacquire
all of the channels again.

You cannot access the diagnostic page when the internet goes out because the modem has turned off its
DHCP server and you already have a public IP address. If the signals are lost, and the modem releases
your public ip, its built in DHCP server will activate and provide you with an address similar to
192.168.100.X depending on how many people have previously been rigged into your modem.

This unfortunatly is not normal, but it can be bypassed. If you program your NIC card with the following
settings, you will be able to walk into the modem and check your diagnostics page whenever you'd like, but
you will have issues connecting to the internet unless you change them back.

IP: 192.168.100.10
Subnet: 255.255.255.0
Gateway: 192.168.100.1
DNS: Not Required
Solian

Solian to kanatamike

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to kanatamike
said by kanatamike:

I'm also having periodic disconnects. We don't notice it every day, but when we do notice it, it's always in the evenings. It's happening tonight. The internet connection will disappear for 30-60 seconds (near 100% packet loss) and then come back. Some nights are worse than others and some nights it doesn't happen at all. This has been going on for about three weeks.

My modem is in the basement, so I can't see the light pattern at the time the internet goes out, but I don't think mine changes as it wouldn't be able to reconnect in the time that it takes me to get to the basement.

Teksavvy is not providing any reasonable suggestions for troubleshooting. They want me to connect directly to the modem. That's not a problem, but then what? Do I sit there staring at the screen for hours or days until the problem starts happening again? And tell everyone in the house the can't use the internet for that time period?

I'm thinking I'll be cancelling my service over this problem if Teksavvy can't fix it.

The best time to figure out whats causing your internet to go down is to catch it in the act.

Bypassing any routers / switches in your home network just eliminates the possibility that it could be a
end user device causing these issues.

If your seeing %100 packet loss during these frequent disconnects, you may have an intermittent signal issue as well.

Depending on the make/model of your modem, the signal/diagnostic page will show you signal levels for your downstream and upstream as well as your SNR (Signal to Noise Ratio). Your downstream power levels should be sitting anywhere between -11 dBmV to +11 dBmV. Upstream should be sitting at 35-52 dBmV. Your SNR values (which are shown next to your downstream) should be sitting anywhere from 35+ dB and above.

If you are having signal issues (from the sounds of it), check your modem when you find your internet is down. If things don't match up and values are out of place, you really are having signal issues and you need to contact teksavvy ASAP.

oceros37
join:2013-07-20
St Thomas, ON

1 edit

oceros37 to Solian

Member

to Solian
said by Solian:

You cannot access the diagnostic page when the internet goes out because the modem has turned off its
DHCP server and you already have a public IP address. If the signals are lost, and the modem releases
your public ip, its built in DHCP server will activate and provide you with an address similar to
192.168.100.X depending on how many people have previously been rigged into your modem.

This unfortunatly is not normal, but it can be bypassed. If you program your NIC card with the following
settings, you will be able to walk into the modem and check your diagnostics page whenever you'd like, but
you will have issues connecting to the internet unless you change them back.

IP: 192.168.100.10
Subnet: 255.255.255.0
Gateway: 192.168.100.1
DNS: Not Required

It's more likely he has a router in the loop.
The router has a public IP through the network. When the modem sync drops, the router is likely not refreshing the DHCP info to get the 192.168.100.x ip that is active now that the modem has lost sync. It's sitting there trying to use the no-longer-active public IP.

If you access the router and renew the DHCP lease, you'll likely end up with the 192.168.100.x ip, and then you are able to access the modem interface. Alternatively you can power cycle your router after the modem sync is lost.

Or plug your computer direct to the modem.

Setting a static IP address should -not- be required if the modem lights are flashing/attempting to sync.
kanatamike
join:2013-07-19
Kanata, ON

kanatamike to Solian

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