Question Unstable internet Disconnects randomly

seperoph

Distinguished
Oct 25, 2012
73
1
18,635
I have started to notice that my internet is disconnecting randomly and recently it has gotten to the point of it will do it pretty much constantly and the modem gives tons of t3 and t4 errors and sometimes I cannot even access the modems page as if its frozen.
ps. I am wired into the router
I have a router and modem separate,
Router-ASUS AC1300 Wifi Router(RT-ACRH13)
Modem- Motorola MB7621 Cable Modem

Here is the connection page for the modem.
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Oct 17, 2021
3
1
10
Your downstream levels are 10-14 (should be as close to 0 as possible) and your upstream levels are 23 (very poor, should be closer to 38-45).

Your snr is 38-39 which is pretty good (higher the better but I'd say yours is above average).

Even with those downstream levels, it's still usable. However the upstream levels are far far too low. Your modem is disconnecting because of this.

I come from a heavy gaming background so it pains me to even read this thinking about gaming on it. I can't possibly imagine the latency and packet loss issues. Ugh.

I have outlined a solution below, but it is based on the assumption that the coax from your wall is going directly into the modem with no splitters or anything in between. If there is anything between your modem and the coax coming from your wall, let me know.


So here is what you'll need to do. You have a couple different options but I've only listed the most cost effective method below. You will need to purchase the following:

- A good quality Coax cable. You will need one short one, maybe 1-3ft or less, and one long enough to reach your modem.
Reasoning: Although signal levels are mainly something that is out of your hands and something that ISPs have to fix, there should not be this much fluctuation/spread between your downstream levels. Purchase a double or triple shielded coax cable to prevent any noise or ingress from your end.

- A good quality 5 way splitter. None of that gold plated gimmicky nonsense (although most gimmicky splitters are often advertised as gold plated, not all gold plated splitters are gimmicky). The range of the splitter should be at least 5-1050 if you only have a modem connected to the splitter, and at least 5-2050 if you have a modem and TV line connected to the splitter.
Reasoning: With every split you make, upstream levels increase by 3.5 and downstream levels reduce by 3.5. With a 5 way splitter, your upstream would increase to 37.5 which is at our targeted range and your downstream would decrease to -1 which is also in our targeted range. 5-1050MHz range is where internet operates 1050-2050 is typically where TV operates. You don't want the two mixing.

- Optional but highly recommended purchase: MoCA filter
Reasoning: Prevents excess noise and leaks from neighbors and others coming onto your connection. Although that SNR is decent, I'm sure it takes dips during peak hours when your neighbors and those on the same node as you are on it. Although the filter won't prevent congestion related issues, it will prevent signals from those homes crossing into yours and vice versa.

- Optional but highly recommended purchase: Coax caps/terminators
Reasoning: The empty ports on your splitter will also throw some noise into the line so caps/terminators to cover those ports are recommended to prevent that.


All in all, your new wiring should look like this:

Before - Coax port in wall --> coax cable --> modem --> ethernet --> router

After - Coax port in wall --> MoCA filter --> shielded coax cable (short) --> "IN" port of 5 way splitter --> "OUT" port of 5 way splitter --> shielded coax cable (length to modem) --> modem --> ethernet (hopefully already cat 5e or above) --> router

Congratulations your line just became 10x more strong and stable than before along with in line signal levels.



I'd post the links to these products but I'm not sure if I'm allowed to. Hope I solved your issue and let me know if your wiring situation is different than what I presumed.
 
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I would call the cable company . In your case all the signals are too strong. The upstream levels maybe low but that is because the cable company equipment is getting too much signal from you and telling your equipment to transmit at lower power to try to compensate for this.

What the cable company will do is put a small filter called a attenuator in the line to absorb some of the extra signals. You can do this yourself but this is something the ISP can do easier because you would have to buy a couple different strength ones and see which works best. The ISP test equipment lets them get the correct one easier.
 

seperoph

Distinguished
Oct 25, 2012
73
1
18,635
Your downstream levels are 10-14 (should be as close to 0 as possible) and your upstream levels are 23 (very poor, should be closer to 38-45).

Your snr is 38-39 which is pretty good (higher the better but I'd say yours is above average).

Even with those downstream levels, it's still usable. However the upstream levels are far far too low. Your modem is disconnecting because of this.

I come from a heavy gaming background so it pains me to even read this thinking about gaming on it. I can't possibly imagine the latency and packet loss issues. Ugh.

I have outlined a solution below, but it is based on the assumption that the coax from your wall is going directly into the modem with no splitters or anything in between. If there is anything between your modem and the coax coming from your wall, let me know.


So here is what you'll need to do. You have a couple different options but I've only listed the most cost effective method below. You will need to purchase the following:

- A good quality Coax cable. You will need one short one, maybe 1-3ft or less, and one long enough to reach your modem.
Reasoning: Although signal levels are mainly something that is out of your hands and something that ISPs have to fix, there should not be this much fluctuation/spread between your downstream levels. Purchase a double or triple shielded coax cable to prevent any noise or ingress from your end.

- A good quality 5 way splitter. None of that gold plated gimmicky nonsense (although most gimmicky splitters are often advertised as gold plated, not all gold plated splitters are gimmicky). The range of the splitter should be at least 5-1050 if you only have a modem connected to the splitter, and at least 5-2050 if you have a modem and TV line connected to the splitter.
Reasoning: With every split you make, upstream levels increase by 3.5 and downstream levels reduce by 3.5. With a 5 way splitter, your upstream would increase to 37.5 which is at our targeted range and your downstream would decrease to -1 which is also in our targeted range. 5-1050MHz range is where internet operates 1050-2050 is typically where TV operates. You don't want the two mixing.

- Optional but highly recommended purchase: MoCA filter
Reasoning: Prevents excess noise and leaks from neighbors and others coming onto your connection. Although that SNR is decent, I'm sure it takes dips during peak hours when your neighbors and those on the same node as you are on it. Although the filter won't prevent congestion related issues, it will prevent signals from those homes crossing into yours and vice versa.

- Optional but highly recommended purchase: Coax caps/terminators
Reasoning: The empty ports on your splitter will also throw some noise into the line so caps/terminators to cover those ports are recommended to prevent that.


All in all, your new wiring should look like this:

Before - Coax port in wall --> coax cable --> modem --> ethernet --> router

After - Coax port in wall --> MoCA filter --> shielded coax cable (short) --> "IN" port of 5 way splitter --> "OUT" port of 5 way splitter --> shielded coax cable (length to modem) --> modem --> ethernet (hopefully already cat 5e or above) --> router

Congratulations your line just became 10x more strong and stable than before along with in line signal levels.



I'd post the links to these products but I'm not sure if I'm allowed to. Hope I solved your issue and let me know if your wiring situation is different than what I presumed.
I am going to order parts today, And everything should be here in a few days hopefully.
 
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seperoph

Distinguished
Oct 25, 2012
73
1
18,635
Sorry for the extreme delay a lot happened in the time since my last post.

The setup seems to have help my numbers quite a bit but I still have large amount of t3 and t4 time outs, I have also noticed I have been getting TLV-11 - unrecognized OID;CM-MAC on every modem reboot don't know if that could be part of the issue or not, Any help resolving this issue would be greatly appreciated . Here is the latest numbers

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Much better but the upstream levels are still a bit low. The recommended lowest value is 40-45 but some say 35 is acceptable. Since the max value is in the low 50 it seems this value has a very narrow range it works well in.

Unfortunately you can not know the signal levels this translates to at the ISP side. What you do know is that the ISP equipment is telling your modem to reduce it power because it thinks the signal is too strong that it is receiving. The problem could be on the ISP side.

Most t3/t4 errors just mean the modem and the ISP equipment are having trouble communicating.