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#1 July 18 2017

Adnan
Member

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.p … 16#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/billio … -5200s.txt

Last edited by Adnan (August 6 2017)

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#2 July 18 2017

nuclearcat
Member

Re: How to use SNR tweaking for a faster or more stable connection

It is just a hack for decreasing SNR margin, it will make connection faster, but much more unstable.

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#3 July 18 2017

anayman_k7
Member

Re: How to use SNR tweaking for a faster or more stable connection

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

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#4 July 27 2017

nefe_lpmk
Member

Re: How to use SNR tweaking for a faster or more stable connection

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-7939 … 50x250.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.

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#5 August 3 2017

Kareem
Member

Re: How to use SNR tweaking for a faster or more stable connection

For D-link modems ...

https://i.gyazo.com/2861cf1a5e5782159e7 … e15955.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

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#6 August 3 2017

omar_killer
Member

Re: How to use SNR tweaking for a faster or more stable connection

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?

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#7 August 3 2017

wollyka
Member

Re: How to use SNR tweaking for a faster or more stable connection

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

Last edited by wollyka (August 3 2017)

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#8 August 3 2017

omar_killer
Member

Re: How to use SNR tweaking for a faster or more stable connection

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

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#9 August 3 2017

Adnan
Member

Re: How to use SNR tweaking for a faster or more stable connection

omar_killer wrote:

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?

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
6510597160.png
87.5% throughput

Post-tweak - 7.2Mbps sync
6510622210.png
81.9% throughput

204% higher throughput
225% higher sync rate
0% errors

Last edited by Adnan (August 3 2017)

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#10 August 4 2017

nefe_lpmk
Member

Re: How to use SNR tweaking for a faster or more stable connection

Anyone got a guide on how to tweak TP-link modems (VR-400)

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#11 August 4 2017

Hassan
Member

Re: How to use SNR tweaking for a faster or more stable connection

nefe_lpmk wrote:

Anyone 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.

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#12 August 4 2017

dio
Member

Re: How to use SNR tweaking for a faster or more stable connection

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?

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#13 August 4 2017

wollyka
Member

Re: How to use SNR tweaking for a faster or more stable connection

SNR tweaking does not work with IDM /GDS. The SNR changes but the speed is locked at whatever they chose.

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#14 August 5 2017

Kareem
Member

Re: How to use SNR tweaking for a faster or more stable connection

No way to tweak the thomson TG585 V8 although it's very easy on the V7, the V8 adslctl command was removed .

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#15 August 11 2017

313
Member

Re: How to use SNR tweaking for a faster or more stable connection

Kareem wrote:

For D-link modems ...

https://i.gyazo.com/2861cf1a5e5782159e7 … e15955.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?

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#16 August 11 2017

Adnan
Member

Re: How to use SNR tweaking for a faster or more stable connection

313 wrote:
Kareem wrote:

For D-link modems ...

https://i.gyazo.com/2861cf1a5e5782159e7 … e15955.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 ?

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#17 August 13 2017

313
Member

Re: How to use SNR tweaking for a faster or more stable connection

Adnan wrote:
313 wrote:
Kareem wrote:

For D-link modems ...

https://i.gyazo.com/2861cf1a5e5782159e7 … e15955.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

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#18 August 13 2017

Adnan
Member

Re: How to use SNR tweaking for a faster or more stable connection

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.

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#19 August 13 2017

mohammadk97
Member

Re: How to use SNR tweaking for a faster or more stable connection

Kareem wrote:

No 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.

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#20 August 14 2017

Kareem
Member

Re: How to use SNR tweaking for a faster or more stable connection

mohammadk97 wrote:
Kareem wrote:

No 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 :

003bf1fe6500a1aaa4c7a315086a9fc1.png

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#21 August 14 2017

Adnan
Member

Re: How to use SNR tweaking for a faster or more stable connection

I noticed today that my DSLAM's target SNR margin was set to 8dB (I am on Sodetel DSP, but I'm not sure who controls this). It was set to 10dB until yesterday. It seems that they're able to put more load on the network so they decreased the SNRM for extra speed.

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#22 August 14 2017

Kareem
Member

Re: How to use SNR tweaking for a faster or more stable connection

Adnan wrote:

I noticed today that my DSLAM's target SNR margin was set to 8dB (I am on Sodetel DSP, but I'm not sure who controls this). It was set to 10dB until yesterday. It seems that they're able to put more load on the network so they decreased the SNRM for extra speed.

Usually it should be the other way around when they have high load since higher SNRM improves stability unless i'm mistaken.

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#23 August 15 2017

Adnan
Member

Re: How to use SNR tweaking for a faster or more stable connection

Kareem wrote:
Adnan wrote:

I noticed today that my DSLAM's target SNR margin was set to 8dB (I am on Sodetel DSP, but I'm not sure who controls this). It was set to 10dB until yesterday. It seems that they're able to put more load on the network so they decreased the SNRM for extra speed.

Usually it should be the other way around when they have high load since higher SNRM improves stability unless i'm mistaken.

Not sure we understood each other correctly.

But what I'm speculating here, rephrased:

Sodetel put the target SNRM to 10dB initially. They tested it and found that their network can handle more load and still be stable, so they lowered the SNRM to 8dB to give more speed. Now the load is higher than before, but still not high enough to cause stability problems from their side.

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#24 August 16 2017

Mylo89
Member

Re: How to use SNR tweaking for a faster or more stable connection

@Adnan, what about Thomson modem tg 585 v7

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#25 August 16 2017

Adnan
Member

Re: How to use SNR tweaking for a faster or more stable connection

@Mylo89 mohamadk97 has the same modem. It has a broadcom chipset so in theory the tweak should work. But unfortunately it didn't for him. Can you try the broadcom method provided by Kareem to confirm ?

If it fails, you can try flashing a custom firmware as Kareem suggests.

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