How can I tell what my attenuation "should" be?

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chevrolux

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#837761 16-Jun-2013 19:53

Hi Cyril, just for your info, the VDSL splitter is supposed to be installed behind the jackpoint that services the VDSL Modem in houses that can only be done by using pre-existing wiring. The POTS (Plain Old Telephone Service) circuit is then to be "back-fed" from that point. Theoretically the installation should be done with a new Cat5e cable from POE (Point of Entry) to Modem JP, the reality is this sometimes cannot be done and existing wiring is used, although the pairs should be "groomed" to give as perfect circuit as possible. Great that you fixed their line and increased their speed dramatically.

Why on earth would you waste extra pairs to get the POTS back to the demarc just for the sake of putting the splitter behind the jack.
The splitter SHOULD be installed in the ETP. It is the size it is for a reason, it fits in the box. This install that Cyril is talking about was obviously done by a Chorus tech getting paid on codes and just wanted to get in and out as fast as possible. In doing that it just flat out wasn't installed properly.

And I really wouldn't try schooling Cyril on these matters....

plambrechtsen

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#837763 16-Jun-2013 19:55

overkill:
cyril7: Hi Behodar, cannot comment on the specifics of your line, but I was at a house yesterday that was on the Telecom VDSL2 trial, had 13.5dB attenuation and sync'd at 42Mb/s down, 10Mb/s up and by my reckoning (my trip meter as I drove away) was 800m from the Exchange.

I should point out that this house had previously had a master filter installed by Chorus specifically for the VDSL2 service, the filter had been installed directly behind the faceplate at the modem post several phone sockets (with non filtered phones including a pert on them) and had 8m or so or trurip from the demarc to a screw terminal mess in the ceiling. Would be interesting if Chorus credit the master install cost. Before I arrived the sync was 20Mb/s up and 10Mb/s down and showing 14dB atten.

Cyril
Hi Cyril, just for your info, the VDSL splitter is supposed to be installed behind the jackpoint that services the VDSL Modem in houses that can only be done by using pre-existing wiring. The POTS (Plain Old Telephone Service) circuit is then to be "back-fed" from that point. Theoretically the installation should be done with a new Cat5e cable from POE (Point of Entry) to Modem JP, the reality is this sometimes cannot be done and existing wiring is used, although the pairs should be "groomed" to give as perfect circuit as possible. Great that you fixed their line and increased their speed dramatically.

Brilliant. Telling Cryil7 how a master filter is supposed to be installed on your first post. That really put a smile on my face.

overkill

222 posts

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#837767 16-Jun-2013 20:07

chevrolux:
Hi Cyril, just for your info, the VDSL splitter is supposed to be installed behind the jackpoint that services the VDSL Modem in houses that can only be done by using pre-existing wiring. The POTS (Plain Old Telephone Service) circuit is then to be "back-fed" from that point. Theoretically the installation should be done with a new Cat5e cable from POE (Point of Entry) to Modem JP, the reality is this sometimes cannot be done and existing wiring is used, although the pairs should be "groomed" to give as perfect circuit as possible. Great that you fixed their line and increased their speed dramatically.

Why on earth would you waste extra pairs to get the POTS back to the demarc just for the sake of putting the splitter behind the jack.
The splitter SHOULD be installed in the ETP. It is the size it is for a reason, it fits in the box. This install that Cyril is talking about was obviously done by a Chorus tech getting paid on codes and just wanted to get in and out as fast as possible. In doing that it just flat out wasn't installed properly.

And I really wouldn't try schooling Cyril on these matters....

The Splitter is installed at the Jackpoint as per Chorus standards for VDSL, ADSL it is installed at POE, but you would of known that being a telco contractor out of Palmy ;) It's not wasting any pairs for the POTS, the circuit is direct using a pair from POE to the Jackpoint for VDSL, pair going back is for POTS, it's the same as if it was for ADSL but around the other way.

"Setting the Standard in Quality and Commitment"

overkill

222 posts

Master Geek

#837768 16-Jun-2013 20:08

plambrechtsen:
overkill:
cyril7: Hi Behodar, cannot comment on the specifics of your line, but I was at a house yesterday that was on the Telecom VDSL2 trial, had 13.5dB attenuation and sync'd at 42Mb/s down, 10Mb/s up and by my reckoning (my trip meter as I drove away) was 800m from the Exchange.

I should point out that this house had previously had a master filter installed by Chorus specifically for the VDSL2 service, the filter had been installed directly behind the faceplate at the modem post several phone sockets (with non filtered phones including a pert on them) and had 8m or so or trurip from the demarc to a screw terminal mess in the ceiling. Would be interesting if Chorus credit the master install cost. Before I arrived the sync was 20Mb/s up and 10Mb/s down and showing 14dB atten.

Cyril
Hi Cyril, just for your info, the VDSL splitter is supposed to be installed behind the jackpoint that services the VDSL Modem in houses that can only be done by using pre-existing wiring. The POTS (Plain Old Telephone Service) circuit is then to be "back-fed" from that point. Theoretically the installation should be done with a new Cat5e cable from POE (Point of Entry) to Modem JP, the reality is this sometimes cannot be done and existing wiring is used, although the pairs should be "groomed" to give as perfect circuit as possible. Great that you fixed their line and increased their speed dramatically.

Brilliant. Telling Cryil7 how a master filter is supposed to be installed on your first post. That really put a smile on my face.

Cheers for that, glad I put a smile on your face.

"Setting the Standard in Quality and Commitment"

sbiddle

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#837770 16-Jun-2013 20:12

cyril7: Hi Behodar, cannot comment on the specifics of your line, but I was at a house yesterday that was on the Telecom VDSL2 trial, had 13.5dB attenuation and sync'd at 42Mb/s down, 10Mb/s up and by my reckoning (my trip meter as I drove away) was 800m from the Exchange.

I should point out that this house had previously had a master filter installed by Chorus specifically for the VDSL2 service, the filter had been installed directly behind the faceplate at the modem post several phone sockets (with non filtered phones including a pert on them) and had 8m or so or trurip from the demarc to a screw terminal mess in the ceiling. Would be interesting if Chorus credit the master install cost. Before I arrived the sync was 20Mb/s up and 10Mb/s down and showing 14dB atten.

Cyril

This also shows attenuation isn't everything - it's simply an indicator of the local loop length, it's not an indicator of actual line performance.

The bitloading graph is what really shows what's going on with the line, and it's something most people have no idea about.

chevrolux

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#837777 16-Jun-2013 20:26

Yea can't say I attended the latest 'training' given by Chorus in regards to VDSL. But if they are telling contractors to put splitters behind the jacks I am glad I didn't go because I would of told them they are flat out wrong. There would be no benefit to doing that. Might as well put the splitter where it is made to go... in the ETP.

Also the boys that went to the VDSL training said the main point that got put across many times was 'you can't use an ADSL on VDSL'. I really do wonder about the people at Chorus some times...

sbiddle

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#837781 16-Jun-2013 20:31

I fail to see how it's really going to save any time for the average install. Using this method you need to understand the exact wiring path and still need to open every jack to scotchlok the incoming pair and then punch down the new pair for voice. If you're going to all this effort you may as well just install the filter at the ETP where it was designed!

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chevrolux

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#837786 16-Jun-2013 20:39

This is obviously a classic Chorus directive that has come from some dude in an office that has never actually worked on the network.

Bunch of numptys.

overkill

222 posts

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#837787 16-Jun-2013 20:43

chevrolux: Yea can't say I attended the latest 'training' given by Chorus in regards to VDSL. But if they are telling contractors to put splitters behind the jacks I am glad I didn't go because I would of told them they are flat out wrong. There would be no benefit to doing that. Might as well put the splitter where it is made to go... in the ETP.

Also the boys that went to the VDSL training said the main point that got put across many times was 'you can't use an ADSL on VDSL'. I really do wonder about the people at Chorus some times...

You didn't miss a thing not attending. A couple of years ago when we where trialing VDSL in Karori (the test-pot for all new platforms), the difference was significant in older homes with old home wiring to have the splitter behind the JP instead of ETP. The standard was set back then for using existing wiring, you still can't beat a Cat cable back to POE though.

"Setting the Standard in Quality and Commitment"

overkill

222 posts

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#837788 16-Jun-2013 20:49

chevrolux: This is obviously a classic Chorus directive that has come from some dude in an office that has never actually worked on the network.

Bunch of numptys.

You mean like the Numpty that made the rule for sealing the bottom of an aerial fed ETP with Mastic Tape when mounted 2 stories up.

I'm not trying to stir and hopefully didn't come across as a complete tool, but that is just Chorus standards for VDSL, so if you see a filter behind a jackpoint and they have VDSL, it was installed the "correct" way, even if it doesn't look right.

"Setting the Standard in Quality and Commitment"

cyril7

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#837902 17-Jun-2013 07:31

Hi, well I dont care where you place the filter, at the end of the day an un-stubbed 100ohm transmission line from DSLAM to modem must be achieved, END OF STORY. If you put it behind the faceplate and back feed the voice then fine, but personally I think I will stay with the ETP as most places split straight out of the ETP.

In the situation I hit on saturday, the chorus tech got it all wrong, there were two voice stubs that remain on the inbound line before the filter that he failed to trace, he also failed to remove sone trurip and a screw termainal rats nest, I think the 20 > 42MB/s increase in download speed speaks for itself.

It saddens me that Chorus have techs running around doing such poor work, I know this is not normally the case, most guys on the job seem to know the right stuff, clearly this guy had no idea.

Cheers
Cyril

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