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Bobby_Valentino
(fountain of knowledge) Thu 22-Mar-12 20:00:41

FTTC Installation Day Prep Work

[link to this post]

Hi

So iv got a install date next week for FTTC to be installed, just wanted to know what I should be taking a note of when the engineer arrives such as the attainable rates on his JDSU, current sync rates...is thers anything else to take note of on the day?

TIA.

Edited by Bobby_Valentino (Thu 22-Mar-12 20:13:09)

deleted
(deleted) Thu 22-Mar-12 20:08:53

Re: FTTC Installation Day Drep Work

[re: Bobby_Valentino] [link to this post]

These are the most useful details (not my own connection's stats):-

JDSU Stats

These are from my own connection when experiencing just some of my connection problems, but I failed to get the estimated length:-

More JDSU Stats

Edited by deleted (Thu 22-Mar-12 20:16:53)

Bobby_Valentino
(fountain of knowledge) Thu 22-Mar-12 20:27:03

Re: FTTC Installation Day Drep Work

[re: deleted] [link to this post]

In reply to a post by Bald_Eagle1:
These are the most useful details (not my own connection's stats):-

JDSU Stats

These are from my own connection when experiencing just some of my connection problems, but I failed to get the estimated length:-

More JDSU Stats

Iv noticed it shows the 8c profile, do the JDSU's show the 17a profile?

deleted
(deleted) Thu 22-Mar-12 20:29:13

Re: FTTC Installation Day Drep Work

[re: Bobby_Valentino] [link to this post]

Those were old photo's, from a few months before 17a was implemented, so I imagine 17a would now be displayed.

Zarjaz
(knowledge is power) Thu 22-Mar-12 21:54:26

Re: FTTC Installation Day Drep Work

[re: deleted] [link to this post]

It certainly is.

I notice in the second picture how low the downstream snr is for what was presumably an 8c service.....

Zarjaz

Zarjaz
(knowledge is power) Thu 22-Mar-12 21:58:13

Re: FTTC Installation Day Prep Work

[re: Bobby_Valentino] [link to this post]

Take a note of it all, downstream and upstream attenuation, snr sync rates, achievable sync rates. There's an error counter to seen on the 'manual' test (as shown in the first photo linked). Also a bits per bin graph ..... happy days.

Zarjaz

deleted
(deleted) Thu 22-Mar-12 22:31:20

Re: FTTC Installation Day Drep Work

[re: Zarjaz] [link to this post]

In reply to a post by Zarjaz:
I notice in the second picture how low the downstream snr is for what was presumably an 8c service.....

It was indeed 8c at the time the photo was taken.

SNR never gets much above 6dB.
This is from the modem itself, today:-

Text

Retrain Reason: 2
Max:    Upstream rate = 5757 Kbps, Downstream rate = 33852 KbpsPath:   0, Upstream rate = 5771 Kbps, Downstream rate = 29475 Kbps
 Link Power State:       L0
Mode:                   VDSL2 Annex BVDSL2 Profile:          Profile 17a
TPS-TC:                 PTM ModeTrellis:                U:ON /D:ON
Line Status:            No DefectTraining Status:        Showtime
                Down            UpSNR (dB):        5.8             6.0
Attn(dB):        0.0             0.0Pwr(dBm):        12.3            6.3

& these are the other stats from the modem, again from the same time today (07:00):-

Text

Discovery Phase (Initial) Band Plan
US: (0,95) (868,1207) (1972,2783) DS: (32,859) (1216,1963) (2792,3939) 
Medley Phase (Final) Band PlanUS: (0,95) (868,1207) 
DS: (32,859) (1216,1963)        VDSL Port Details       Upstream        Downstream
Attainable Net Data Rate:       5757 kbps         33852 kbpsActual Aggregate Tx Power:        6.3 dBm          12.3 dBm
============================================================================  VDSL Band Status        U0      U1      U2      U3      D1      D2      D3
  Line Attenuation(dB):  8.3     53.3    64.1     N/A    21.6    63.4    0.1    Signal Attenuation(dB):  14.5    52.6     N/A     N/A    21.6    63.4     N/A   
        SNR Margin(dB):  5.9     6.0      N/A     N/A    5.6     5.9      N/A            TX Power(dBm): -4.4     5.8      N/A     N/A    11.0    6.3      N/A

Unlike a JDSU, the modem reports a connection's attenuation values for each band plan rather than an overall value & I don't know how to convert my modem stats to the equivalent JDSU reading.

Can you glean anything from those stats such as attenuation too high, SNR too low, Power too low etc. to suggest why I cannot maintain a connection much above 30Mb sync speed?

I got 35Mb sync speed when FTTC was first installed on the 8c profile back in June 2011.

My "real" distance from the cabinet is probably 850m (as one engineer reported from BT's Network Records via his laptop), but JDSUs have variously reported it as 900m, 1000m, 1100m.

My ISP has very recently put me on their 80Mb/20Mb trial, just as an experiment on a sub-40Mb connection - to see what (if any) difference it made.

As we suspected, as I get nothing at all from the higher 17a DS band plan (tones (2792,3939) ), it has made no difference whatsoever.

Edited by deleted (Thu 22-Mar-12 22:36:29)

Zarjaz
(knowledge is power) Fri 23-Mar-12 06:56:08

Re: FTTC Installation Day Drep Work

[re: deleted] [link to this post]

Unlike a JDSU, the modem reports a connection's attenuation values for each band plan rather than an overall value

Nah, it does both.

Experience shows, that on many VDSL lines using an 8c or 17a profile, and an up to 40 cap. There is often a 'surplus' of snr, it being so low on your line would imply it wasn't so happy. I know we have been down this route before. My guess is just a poor D-side pair/length of cable, which is making the sync rate so poor.

Zarjaz

deleted
(deleted) Fri 23-Mar-12 08:46:20

Re: FTTC Installation Day Drep Work

[re: Zarjaz] [link to this post]

Cheers Zarjaz,

In reply to a post by Zarjaz:
Unlike a JDSU, the modem reports a connection's attenuation values for each band plan rather than an overall value

Nah, it does both.

If you mean the HG612 modem, it appears to report single DS & US attenuation values only when used on an ADSL connection:-

Text
1 23 45 67	SNR (dB): 6.2 5.7 Attn(dB): 49.0 27.3Pwr(dBm): 19.6 12.8 But it won't report anything from pbParams:-"Currently not in VDSL modulation --pbParams is only for VDSL mode"

Whereas on a VDSL2 connection, it only shows 0.0 for the DS & US single attenuation values:-

Text
1 23	SNR (dB): 5.8 6.0 Attn(dB): 0.0 0.0Pwr(dBm): 12.3 6.3

If you meant the JDSU, it would be interesting to see how closely related the JDSU & HG612 split band plan readings are on the same VDSL2 connection.
(as a comparison with the single DS & US attenuation values usually reported by the JDSU).

Experience shows, that on many VDSL lines using an 8c or 17a profile, and an up to 40 cap. There is often a 'surplus' of snr, it being so low on your line would imply it wasn't so happy. I know we have been down this route before. My guess is just a poor D-side pair/length of cable, which is making the sync rate so poor.

Yep, I have seen quite a few user stats from various speeds of VDSL2 connections.
DS SNR over 30dB has been the highest I have seen so far (attainable rate almost 130Mb):-

Text

Max:    Upstream rate = 40343 Kbps, Downstream rate = 127540 Kbps
Path:   0, Upstream rate = 10000 Kbps, Downstream rate = 39998 Kbps 
Link Power State:       L0Mode:                   VDSL2 Annex B
VDSL2 Profile:          Profile 17aTPS-TC:                 PTM Mode
Trellis:                U:ON /D:ONLine Status:            No Defect
Training Status:        Showtime                Down            Up
SNR (dB):        30.8            30.3Attn(dB):        0.0             0.0
Pwr(dBm):        13.3           -8.6

I don't suppose you have an urgent need to visit any relatives Oop North (near Oldham) while carrying a JDSU & a Mole 301c TDR tester in your back pockets do you? wink

Paul.

Zarjaz
(knowledge is power) Fri 23-Mar-12 17:05:55

Re: FTTC Installation Day Drep Work

[re: deleted] [link to this post]

No, I did mean the JDSU reports all that stuff.

Oldham you say ? .......... I doubt they'll grant me a visa. smile

Zarjaz

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