• Networking
  • How to use SNR tweaking for a faster or more stable connection

TOC
1. What's this ?
2. Will it make my connection faster ?
3. Will it make my connection more stable ?
4. What modems is it compatible with ?
5. How do I do it ?
6. Modem stats quirks

1. What's this ?
SNR tweaking is basically setting a target SNR margin value manually. This value is normally negotiated between your modem and the exchange while your ADSL connection is being established. By changing the SNR margin manually, you can modify the speed and stability of your ADSL connection. We will use some telnet commands to apply this.

2. Will it make my connection faster ?
If at the current speed your line is stable enough, you can definitely try to give it even more speed. At some point if you overload it, you will notice either a lot of CRC errors or your modem not being able to sync at all which means you should slow it down again.

3. Will it make my connection more stable ?
If at the current speed your line is facing stability issues, you can try syncing on lower speeds. I have an electricity interference problem on my line, and syncing on 3.5Mbps instead of 5Mbps helped me get a stabler connection.

4. What modems is it compatible with ?
I have only tested it on the TP-Link TD-W8901G. However it should work with any TrendChip-based modem. If you're not using TrendChip, you can google "snr tweak <your chip>" or "snr tweak <your modem>".

Update: if you have a Broadcom-based modem such as the D-Link X1000, check this post: https://lebgeeks.com/forums/viewtopic.php?pid=170216#p170216

5. How do I do it ?
i. First open up your browser and check your modem stats. Check your SNR value and downstream data rate. Mine were 12dB and 5Mbps. Since I'm on 12dB I was sure I could squeeze more juice and push it down to 6dB (don't be afraid to try if you're already on 6dB).

ii. Next, telnet into your modem. The values I will providing in the commands below are values I haven't really understood, but I just went with it by trial and error. However, providing a + value means faster sync rate and a - value means slower sync rate.
YOU CAN EITHER GO WITH MY TRIAL AND ERROR VALUES OR TRY TO UNDERSTAND THE VALUES IN DETAIL BY USING THE LINK BELOW.

Ok as of this writing my speed is 4891Kbps with 12dB SNR.
TP-Link>wan dmt2 set snrm 2000 2000
TP-Link>wan adsl reset
After running the commands above, I waited for about a minute for the modem to resync.
Now I'm getting 5253Kbps. However my SNR still reads 12dB (I'll cover this in the next part).

I will try to push it further (reference is always the base value of 4891Kbps).
TP-Link>wan dmt2 set snrm 5700 5700
TP-Link>wan adsl reset
This got me 7057Kbps but I'm getting lots of CRC errors now, this means I should set a value lower than 5700.

To downgrade the speed from the original speed (in my case 4891Kbps), you'll just have to provide negative values:
TP-Link>wan dmt2 set snrm -1700 -1700
TP-Link>wan adsl reset
Went down to 3347Kbps.

You get how it works at this point, just keep trying numbers.

iii. These changes are lost across reboots, if you're interested in making them persistent check the link below.

6. Modem stats quirks
Now during all these changes, I noticed that the SNR margin displayed by modem always stayed at around 12dB. However, I speculate the displayed value is in someway not real for the following reason:

I have an electric interference problem with the building's elevator. Each time it's in use, my SNR drops to 4dB and even sometimes 1dB. On 4.9Mbps, this SNR drop would cause my connection to stall and the CRC errors to kick in. When I downgraded to 3.5Mbps, the modem would still show that the SNR dropped to 4dB however my connection didn't even stall a bit and I noticed only a few CRC errors which I could certainly eliminate by syncing even slower.


Source / Credits: https://pyro.eu.org/how-to/micro/billion-bipac-5200s.txt
It is just a hack for decreasing SNR margin, it will make connection faster, but much more unstable.
Thanks for this, I'll use it to increase my SNR, I prefer having 9mbps stable without packet loss compared to 10mbps non 100% stable
9 days later
I am wondering if I use modified CAT6 between the wall socket and modem if it would improve my stats.

Also, I am using a socket to connect the RJ11 cable similar to an electricity plug (https://3.imimg.com/data3/KE/NM/MY-7939008/two-pin-top-plug-250x250.jpg) where I plug the RJ in its back and it plugs to the wall like electricity plug. Might this cause degradation of signal?
I will have to redo the wall socket to fix that in case it is.
8 days later
https://m.imgur.com/TbGYVtZ

I just tried using Kareem's command on my X1000 and to my surprise it worked!
My max rate jumped from 13 mbps to 18.7, I lowered my SNR from 15 to 9 so I'll be monitoring my connection in the next few days, is 9db considered very low? will it affect gaming etc?
Are you with Ogero?
Because on IDM, whatever is the SNR margin, the rate is locked.. I lowered mine from 14 to 9 and the rate didn't change at all
Sodetel, but now that you've mentioned it on speedtest.net I'm always getting lower speeds, for example I used to get 11mbps now 14 mbps, I'm planning on moving to ogero next month anyways
omar_killer wrotehttps://m.imgur.com/TbGYVtZ

I just tried using Kareem's command on my X1000 and to my surprise it worked!
My max rate jumped from 13 mbps to 18.7, I lowered my SNR from 15 to 9 so I'll be monitoring my connection in the next few days, is 9db considered very low? will it affect gaming etc?
Seems like the target SNR set by Sodetel is 15dB which is astronomically high, as in too safe.
I'm also with Sodetel and I once requested the SNR to be lower than 15dB they kept saying that it's not them who set it. I can't be a hundred percent sure it's them but seeing your feedback that should be it.

Of course after I discovered I could tweak the SNR by myself, I couldn't care less.

Fresh results:

Pre-tweak - 3.2Mbps sync

87.5% throughput

Post-tweak - 7.2Mbps sync

81.9% throughput

204% higher throughput
225% higher sync rate
0% errors
Anyone got a guide on how to tweak TP-link modems (VR-400)
nefe_lpmk wroteAnyone got a guide on how to tweak TP-link modems (VR-400)
I have the tp-link vr900 and I don't think SNR tweaking can be done on these models :(
If someone knows a way however, it would be highly appreciated.
Can anyone give a step-by-step guide as to how to tweak the SNR for the standard Technicolor DSL modems that ogero gives u?
SNR tweaking does not work with IDM /GDS. The SNR changes but the speed is locked at whatever they chose.
No way to tweak the thomson TG585 V8 although it's very easy on the V7, the V8 adslctl command was removed .
6 days later
Kareem wroteFor D-link modems ...

https://i.gyazo.com/2861cf1a5e5782159e75c72753e15955.png

adsl configure --snr xx

To understand more the value of XX, check the link below :

http://www.increasebroadbandspeed.co.uk/SNR-tweak


basically you wanna reduce the SNR Margin ( not SNR ) in steps of 3dB. reduce and test stability. mine won't go below6 dB

I tried Kareem's Tutorial but with no luck, The error is that Invalid parameter.

My guess is that I haven't entered through configuration terminal since the command

>adsl snr
shows
------the table SNR per tones(carriers) of the interface ADSL2+-----

Downstream Upstream
168 266

any tutorial for dummies?
313 wrote
Kareem wroteFor D-link modems ...

https://i.gyazo.com/2861cf1a5e5782159e75c72753e15955.png

adsl configure --snr xx

To understand more the value of XX, check the link below :

http://www.increasebroadbandspeed.co.uk/SNR-tweak


basically you wanna reduce the SNR Margin ( not SNR ) in steps of 3dB. reduce and test stability. mine won't go below6 dB

I tried Kareem's Tutorial but with no luck, The error is that Invalid parameter.

My guess is that I haven't entered through configuration terminal since the command

>adsl snr
shows
------the table SNR per tones(carriers) of the interface ADSL2+-----

Downstream Upstream
168 266

any tutorial for dummies?
What's your router model ?
Adnan wrote
313 wrote
Kareem wroteFor D-link modems ...

https://i.gyazo.com/2861cf1a5e5782159e75c72753e15955.png

adsl configure --snr xx

To understand more the value of XX, check the link below :

http://www.increasebroadbandspeed.co.uk/SNR-tweak


basically you wanna reduce the SNR Margin ( not SNR ) in steps of 3dB. reduce and test stability. mine won't go below6 dB

I tried Kareem's Tutorial but with no luck, The error is that Invalid parameter.

My guess is that I haven't entered through configuration terminal since the command

>adsl snr
shows
------the table SNR per tones(carriers) of the interface ADSL2+-----

Downstream Upstream
168 266

any tutorial for dummies?
What's your router model ?


DLINK DSL-2750U

Click here to see the photo
The C1 revision of your modem has a Broadcom chipset, however the U1 has a Realtek one. Now if you have a Broadcom chipset and it didn't work, it might be that the manufacturer removed the feature.
Kareem wroteNo way to tweak the thomson TG585 V8 although it's very easy on the V7, the V8 adslctl command was removed .
How can we do it on the v7? I've been trying a lot, and it can't seem to work.
mohammadk97 wrote
Kareem wroteNo way to tweak the thomson TG585 V8 although it's very easy on the V7, the V8 adslctl command was removed .
How can we do it on the v7? I've been trying a lot, and it can't seem to work.
There is a custom Firmware for the V7. Check online but I am not responsible for any damage.

Meanwhile :