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[FrankGarrett]

I live in Ireland and Eircom launched VDSL2/FTTC last year using Huawei's technology. The maximum I can receive from my cabinet 70Mb / 20Mb. I am aroound 350 meters from the cabinet and I can only get 40Mb/10Mb. I should be getting at least 50Mb/20-15Mb from this distance.

There is even a house closer to the cabinet than I am and they're only getting 25Mb. Here is a rough layout of my housing estate I made on Microsoft Paint:



Here is look at my router's stats:



Does anyone know why the speed suddenly drops 40Mb from one house to the next? The housing plots are only 50 feet wide so the telephone line would be around 50 feet longer, too.

I'm able to reveal more hidden stats on my router if anyone is interested in taking a look to see if they can pinpoint a fault somewhere.

[kitz]

According to your line stats your line should be capable of supporting 20Mbps upstream.  You have 16.7 db SNRM, so Im not sure why its not syncing at the higher rate unless its some sort of cap via your ISP.   

Downstream Im not sure about.  hmmm 9dB of SNRm..  does your SNRm fluctuate during the day..  is it possible that your target SNRm is set at 9dB.  We need to find out the answer to those questions before we can give a more definitive answer. A very rough guestimate (its late & BT no longer uses target SNRm for FTTC), but if your target SNrm is set at 9dB that could be costing you 6Mb.. and even more if the line is interleaved.
 
Does your router work with DSLstats?  If so it may be worthwhile grabbing a copy and monitoring what your SNRm is doing over the course of the day.

[waltergmw]

Hi Frank,

From Kitz's sublime answer to the (nearly) ridiculous.
Have you checked your house inside and out for hidden star wiring, crackling phone calls, missing phone filters etc. etc.

Kind regards,
Walter

[boost]

Never seen the equipment but I reckon you've prolly found a configuration issue at that DSLAM.

Perhaps someone here can shed more light...

[FrankGarrett]

According to your line stats your line should be capable of supporting 20Mbps upstream.  You have 16.7 db SNRM, so Im not sure why its not syncing at the higher rate unless its some sort of cap via your ISP.

I'm on the 40/10 profile. I won't be able to get more upload speed without a higher download attainable. Here are a list of the profiles:

Downstream Im not sure about.  hmmm 9dB of SNRm..  does your SNRm fluctuate during the day..  is it possible that your target SNRm is set at 9dB.  We need to find out the answer to those questions before we can give a more definitive answer. A very rough guestimate (its late & BT no longer uses target SNRm for FTTC), but if your target SNrm is set at 9dB that could be costing you 6Mb.. and even more if the line is interleaved.

I believe my ISP limits the noise margin to 9dB and will not allow it to go lower even if it means faster speed for their customers. As of 13:00, it is still 9.8dB.

This is a screenshot from the 16th of July. I was one of the first people to get FTTC/VDSL in my estate because the building of our cabinet was delayed due to planning permission. As more people signed up, the quality of my stats deteriorated slightly.


 

Does your router work with DSLstats?  If so it may be worthwhile grabbing a copy and monitoring what your SNRm is doing over the course of the day.

I just download it there but I don't see my type of router listed for the the Huawei router. I tried logging in anyway and it didn't work. My router is the Huawei HG658c.

[FrankGarrett]

Hi Frank,

From Kitz's sublime answer to the (nearly) ridiculous.
Have you checked your house inside and out for hidden star wiring, crackling phone calls, missing phone filters etc. etc.

Kind regards,
Walter

The problem seems to exist somewhere in my estate because I'm not the only one who is suffering reduced speeds. As you can see from the map I created, one house get 70Mb, while the house next door get 25Mb even though the 25Mb house is closer to the cabinet.

A technician installed a new socket for me and connected it straight to the line coming into my house - the last one was in bad shape. There shouldn't be any problem with internal wiring.

[kitz]

I believe my ISP limits the noise margin to 9dB and will not allow it to go lower even if it means faster speed for their customers. As of 13:00, it is still 9.8dB.

Thank you for that info.  I suspected it may be a Target SNRm but was unsure because in the UK BT has abandoned target SNRm when it comes to the DLM for FTTC.

The other reason I suggested monitoring your SNRm was just to see if it threw anything that may indicate local interference.  Weve had many cases of REIN type faults that have affected say 4-6 surrounding homes.  If you say it doesnt vary then I guess that's that eliminated.

Boost has mentioned a configuration issue at the DSLAM and about the only other thing I could perhaps think of is one of the lines is whats known as a disturber.  This is when one of the copper pairs in the bundle introduces crosstalk (FeXT) to its neighbouring pairs.

QLN graphs can sometimes show up crosstalk. 

My router is the Huawei HG658c.

According to  dmcdonnell, this router has a BCM63168 chipset so DSLstats should work.  Since the Zyxel VMG8324 also contains the same chipset, try selecting that from the options.  If that doesnt work then eric (roseway) may be able to come up with something to get it working for you. 

[NewtronStar]

I suspected it may be a Target SNRm but was unsure because in the UK BT has abandoned target SNRm when it comes to the DLM for FTTC.

Geez Kitz what no target margin of 6dB on FTTC  when did this come into effect and thinking of Baldeagle1 could he get his long awaited 3dB margin if BT has abandoned the TM SNRm 

[roseway]

DSLstats works with the HG658b, so I would expect it to work with the HG658c as well, using the HG658b settings.

[kitz]

I suspected it may be a Target SNRm but was unsure because in the UK BT has abandoned target SNRm when it comes to the DLM for FTTC.

Geez Kitz what no target margin of 6dB on FTTC  when did this come into effect and thinking of Baldeagle1 could he get his long awaited 3dB margin if BT has abandoned the TM SNRm 

Sorry if I didn't make it clear.

I meant that the BToR DLM doesn't use target snr as one of the stages for stability increments now favouring to use rate banding with interleaving.    We don't have a 9db hence me querying it.   I don't know what the Irish ISPs do.

   DLM is a totally separate system. 6db is the default sync spec for rate adaptive DSL. and are independent of each other. Kind of like how BEbroadband didn't have any DLM at all but still had a default 6db target margin.  DLM is a system first invented by BT boffins and it's not a specification of rate adaptive dsl... Whilst the target snrm is.  Most ISPs outside of the uk don't use DLM.

[boost]

Oops, assumed this was BT FTTC

[NewtronStar]

Sorry if I didn't make it clear.

I meant that the BToR DLM doesn't use target snr as one of the stages for stability increments now favouring to use rate banding with interleaving.    We don't have a 9db hence me querying it.   I don't know what the Irish ISPs do.

I understand now my pupils dilated after seeing your post, UK BT has abandoned target SNRm on FTTC, though when I think about it 6dB SNRM is to low for longer noisy lines on FTTC it should be set at say 7.5dB to stop the DLM lowering sync rate with higher interleaveing.