For weeks my internet connection dropping about every 15-30 minutes. Then it comes back after 2-5 minutes. I reported the problem to my ISP, after a day they told me the problem is telephone cables in my apartment and I should repair it. But after midnight, my internet connection is rarely dropping. So If the problem is my telephone cable how my connection is getting better at midnight?. Here are my some dsl values:
--20.00(HOUR)--
noise safety coefficient (dB) (U/D): 8.4 / 8.1
line attenuation (dB) (U/D): 39 / 21
output power (dBm) (U/D): 12 / 21
--01.00(HOUR)--
noise safety coefficient (dB) (U/D): 16.8 / 16.1
line attenuation (dB) (U/D): 38 / 21
output power (dBm) (U/D): 12 / 21
2 Answers
To blame internal house wiring is a bit of a diversion of attention away from other problems. The principal way internal wiring fails, is if the premises are in close proximity to salt air contamination causing corrosion problems. Internal wiring is reasonably well protected from the elements, bird poop and plastic destroying UV rays. The problem usually lies with a badly degraded external copper network.
"Noise safety coefficient" is the same as "SNR margin". It seems that repeated noise on the line has caused the ISP's equipment to increase your SNR, resulting in less disconnections, but also in lower line speed. I note that the value has gone up from about 8 db to 16 db, which is close to the maximum.
The article Broadband SNR Margin Tweak contains much useful information and says :
The exchange equipment attempts to set the downlink connection speed such that there is a sufficiently high SNR margin to guarantee a reliable connection (without regular drops and/or an unacceptable number of errors). This specific margin that the exchange tries to achieve is called the target SNR margin. The higher the target SNR margin, the lower your connection speed.
As part of the Digital Line Management process, the exchange equipment continuously monitors your broadband connection, for example recording the number of times that it drops and the number of errors it suffers. If the line experiences any issues (such as bursts of errors at a particular time), the exchange equipment can increase the target SNR margin – usually in steps of 3 dB. This action – aimed at stabilising the line – reduces the connection speed.
Once the BT exchange equipment has increased the target SNR margin, it can take days for the target SNR margin to be reduced and, in some cases, it is never reduced.
I believe that you experience network congestion and extra line noise during the day, which will cause SNR to automatically rise in stages until the connection stabilizes, but lowering line speed.
The most likely reasons for this is either bad quality of the lines infrastructure or the ISP's equipment, or your ISP having over-committed its lines, or some interference caused by adjacent commercial equipment.
According to the SG DSL Speed Calculator, your Downstream Attenuation of 21 indicates a distance of about 1.5 km, which means enough chances for bad wiring and interference.
The above article I linked lists some ways to manually adjust the SNR values through the router, but that is not a good solution. If your ISP will not fix the problem, you might need to consider some alternatives. Maybe trying other routers is also an idea.
4You should try to plug directly the modem to the phone line and see if you get improvement. You should also see if you have a capacitors that were used in old phone plugs in some countries (see pic).
Know that usually, interference can come from everything that has uses electromagnetic waves OR physical damage (like wet on the cables), faulty filter, or phone line installation close to electrical disturbance sources.
If your DSL subscription line is equal or lower than 8Mbps you can try to configure your router to synchronize with DSLAM using the G.dmt norm (ADSL1) instead of ADSL2+ (G992.5). It's more stable, and stresses way less the line than the other synchronization mode.
(same principle can be done with 12Mbps and ADSL2, not 2+ )
12
