VDSL connection advice

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dimsim

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#112041 24-Nov-2012 09:37

recently had VDSL connected and although the attainable rate was 30mbs/10mbs we only ever acheived 16mbs/7mbs

chorus noted a lot of erros on the line which they thought wa sa wiring fault at our end. They have switch DLM on and the attainable rate has now dropped to 19mbs/10mbs, actual rate is still the same with the same amount of errors.

Before DLM:

Modem Status:            TC Sync (Showtime!)
DSL Config Mode:         AUTO
Trained Mode:            G.993.2 (VDSL2) Profile 8b
TC Mode:                 PTM
Selftest Result:         0x00
DELT configuration:      disabled
DELT state:              not running
Trellis: ON ON
Line Attenuation:         0.0 dB                  0.0 dB
Signal Attenuation:       0.0 dB                  0.0 dB
Noise Margin:            11.5 dB                 14.9 dB
Attainable Rate:        33980 kbits/s            12272 kbits/s
Actual Power:            13.5 dBm                 6.9 dBm
Per Band Status:        D1      D2      D3      U0      U1      U2      U3
Line Attenuation(dB): 15.5 39.0 N/A N/A 33.2 N/A N/A
Signal Attenuation(dB): 15.5    39.0    N/A     N/A     32.2    N/A     N/A
Noise Margin(dB):       11.5    11.5    N/A     N/A     14.9    N/A     N/A

                  DS Channel1     DS Channel0   US Channel1       US Channel0
Speed (kbps):             0            34618             0             10350
Previous Speed:           0                0             0                 0
Reed-Solomon EC:          0          6938927             0            120497
CRC Errors:               0           129894             0                 0
Header Errors:            0           326068             0                 0
Interleave (ms):       0.00            10.00          0.00             15.00
Actual INP:            0.00             0.00          0.00              1.10

After DLM:
Modem Status:            TC Sync (Showtime!)
DSL Config Mode:         AUTO
Trained Mode:            G.993.2 (VDSL2) Profile 8b
TC Mode:                 PTM
Selftest Result:         0x00
DELT configuration:      disabled
DELT state:              not running
Trellis:                 ON                       ON
Line Attenuation:         0.0 dB                  0.0 dB
Signal Attenuation:       0.0 dB                  0.0 dB
Noise Margin:            12.0 dB                 14.7 dB
Attainable Rate:        19388 kbits/s            12208 kbits/s
Actual Power:            11.9 dBm                 6.8 dBm
Per Band Status:        D1      D2      D3      U0      U1      U2      U3
Line Attenuation(dB):   17.4    41.7    N/A     N/A     34.7    N/A     N/A
Signal Attenuation(dB): 17.4    41.7    N/A     N/A     34.2    N/A     N/A
Noise Margin(dB):       11.8    12.1    N/A     N/A     14.7    N/A     N/A

                  DS Channel1     DS Channel0   US Channel1       US Channel0
Speed (kbps):             0            19390             0             10350
Previous Speed:           0                0             0                 0
Reed-Solomon EC:          0            40046             0               344
CRC Errors:               0                8             0                 0
Header Errors:            0               75             0                 0
Interleave (ms):       0.00            16.00          0.00             15.00
Actual INP:            0.00             1.01          0.00              1.10

Chorus tech says they havev a battery fault of some description...

Can anyone make sense of these numbers? I suppose we're reasonably happy with the upstream (7x better than previous wireless connection) but though we have better downstream speed.

Running a Cisco 887V.

sbiddle

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#722172 24-Nov-2012 09:42

The most important thing is your wiring and your distance from the cabinet/exchange.

A VDSL2 rated master splitter is mandatory if you have multiple jackpoints. If you want to avoid installing a splitter you will want to ensure the modem is plugged directly into the incoming line with no other wiring on your premises connected.

Until you can confirm your setup is one of the above it's almost pointless disussing any other possible causes.

dimsim

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#722174 24-Nov-2012 09:45

sbiddle: The most important thing is your wiring and your distance from the cabinet/exchange.

A VDSL2 rated master splitter is mandatory if you have multiple jackpoints. If you want to avoid installing a splitter you will want to ensure the modem is plugged directly into the incoming line with no other wiring on your premises connected.

Until you can confirm your setup is one of the above it's almost pointless disussing any other possible causes.

we paid chorus the $200 to install a master jackpoint. Our router is the only device connected to it.

sbiddle

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#722176 24-Nov-2012 09:48

dimsim:
sbiddle: The most important thing is your wiring and your distance from the cabinet/exchange.

A VDSL2 rated master splitter is mandatory if you have multiple jackpoints. If you want to avoid installing a splitter you will want to ensure the modem is plugged directly into the incoming line with no other wiring on your premises connected.

Until you can confirm your setup is one of the above it's almost pointless disussing any other possible causes.

we paid chorus the $200 to install a master jackpoint. Our router is the only device connected to it.

Cool.. So that's just a dedicated jackpoint solely for DSL? Can you confirm this? It wouldn't be the first time I've seen Chorus install a new jackpoint for VDSL that's not dedicated.

I assume you've had your ISP run fault testing on the line? A huge amount of data is generated by this including graphs that will show if there are issues such as possible bridge taps on your line between the cabinet/exchange and your premises. Because your VDSL meets the minimum 15/5 service guidelines however, you may not have a lot of luck getting changes made though is this is infact a cause.

dimsim

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#722177 24-Nov-2012 10:06

sbiddle:
dimsim:
sbiddle: The most important thing is your wiring and your distance from the cabinet/exchange.

A VDSL2 rated master splitter is mandatory if you have multiple jackpoints. If you want to avoid installing a splitter you will want to ensure the modem is plugged directly into the incoming line with no other wiring on your premises connected.

Until you can confirm your setup is one of the above it's almost pointless disussing any other possible causes.

we paid chorus the $200 to install a master jackpoint. Our router is the only device connected to it.

Cool.. So that's just a dedicated jackpoint solely for DSL? Can you confirm this? It wouldn't be the first time I've seen Chorus install a new jackpoint for VDSL that's not dedicated.

I assume you've had your ISP run fault testing on the line? A huge amount of data is generated by this including graphs that will show if there are issues such as possible bridge taps on your line between the cabinet/exchange and your premises. Because your VDSL meets the minimum 15/5 service guidelines however, you may not have a lot of luck getting changes made though is this is infact a cause.

we were explained at the time that VDSL was line fussy and that it was recommended to have chorus install a dedicated jackpoint. we have previously only ever had dedicated jackpoints installed for ADSL so were happy to go along with this for the additional cost if it meant we'd have better speed/reliability.

Chorus have been out again yesterday, poked around out on the street for a few hours, then dissapeared without saying anything. Out ISP reported back that they had a battery fault that they were looking into?

At luchtime on Thursday Chorus switched DLM on and activated a 48hours DSL analyser - so i guess we'll need to wait for those result to come back next week.

I was just hoping it would be easy for someone to analyse the before and after specs above and give us a clearer idea of what might be happening.

DLM (dynamic line management from what i understand analyse the line then assigns the best profile for the connection. Our profile doesn't appear to have changed but interleaving has, as has the attainable rate - im assuming that this is either due to the battery issue, or an existing cabling fault somewhere. The initial provisioning request came back and said "Good for VDSL - 1.6dB Attenuation" for this site.

blair003

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#722186 24-Nov-2012 10:16

From what I understand there are line profiles (e.g. Profile 8b) and separate DLM profiles. The DLM profile sets a few things including your INP and interleaving. It should do it automatically based on the condition of your line.

I'm not sure what VDSL modem you have (so I'm not used to the report output) and someone will correct me if I am wrong, but the line attenuation your modem is reporting doesn't look great to me and based on that your speeds seem about right.

(But I'm no expert on this subject)

sbiddle

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#722359 24-Nov-2012 17:55

How far actually are you from the cabinet or exchange?

Dyson

Shop now for Dyson appliances (affiliate link).

dimsim

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#722363 24-Nov-2012 18:05

sbiddle: How far actually are you from the cabinet or exchange?

i have no idea where the cabinet is (FJN/R). according to the SAT im in the middle of a cabinetised area and all areas around are also cabinetised and have had vdsl since june 2011. the areas it self couldnt be more than 400m x 400m?

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#722390 24-Nov-2012 19:46

My only recommendation would be to try another modem.

While all you can do is pester your ISP who will in turn pester Chorus, the fact you meet the minimum service guidelines may mean you reach a brick wall.

dimsim

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#722429 24-Nov-2012 21:41

sbiddle: My only recommendation would be to try another modem.

While all you can do is pester your ISP who will in turn pester Chorus, the fact you meet the minimum service guidelines may mean you reach a brick wall.

mmm, what exactly are the minimum service guidelines?

sbiddle

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#722431 24-Nov-2012 21:42

In my post above. 15/5

I'd try another modem first, a Zyxel is your best bet.

dimsim

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#722437 24-Nov-2012 21:59

sbiddle: In my post above. 15/5

I'd try another modem first, a Zyxel is your best bet.

thanks, thought you were referring to a written spec of some description..lol.

the errors being shown that chorus say are line related - could they be modem related? the cisco 887 came highly recommended by the engineers at my ISP and I've always found them to be rock solid. who distributes zyxel gear?