The Connection & Wiring ADSL Install Option

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1080p

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#62886 16-Jun-2010 15:55

I've done no small amount of reading about this since I happened accross this link while browsing the broadband forum: https://www.telecom.co.nz/broadband/select/1,10627,205732-204473,00.html?action=/option

I am curious as to what this install option actually entails; obviously I have a current (working) ADSL connection but according to my (limited) calculations I have a sync rate which is far lower than what it should be:

From my own calculations I should be ~500m from the exchange as Google maps/the crow flies. I understand that this by no means guarantees that the copper is even close to 500m in length but my current sync rate tells me that I should be closer to 1.5km from the exchange. I am willing to admit that I am a few hundred metres off but not a kilometre.

My first suspicion is the wiring in my apartment, which is very old. The cable looks to be in good condition but isn't CAT5 (its about half the size of any CAT cable I have seen). I have a single telephone jackpoint with this cable leading away from it into the hallway and then some sort of makeshift cuboard embedded into the wall. The cuboard is too high for me to reach (I'm in the process of acquiring a ladder) so I can't take a peek inside and assess what state the rest of the cabling is in.

What I'd like to know is what exactly the Telecom (Chorus?) technician would do if I chose this install option (I'm considering an ISP change) to the wiring in my apartment? What I wold love would be for the entire current setup to be removed and have a central splitter installed with CAT cable running to the phone jackpoint. I'd also possibly like another phone plug installed (one for the phone, one for the modem). All of the wiring in this apartment is exposed (the walls are concrete; its an old building) so I would imagine the job would be fairly easy for whomever had to change the cables (there will be no digging about in the walls).

Would this installation option send a technician over to do this for me? If not should I instead consider contracting an electrician?

PANiCnz

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#342362 16-Jun-2010 16:18

Those are pretty good speeds, I think you'd actually have to move into the exchange to get much better.

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#342367 16-Jun-2010 16:30

I wonder if they would let me live in their attic? I can just have a strand of fibre up there and I'd be happy :P

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#342417 16-Jun-2010 18:23

You won't get more than 18Mbit on Telecom wholesale equipment imo, full wiring would be a waste. Chances are the apartment is already wired pretty well.

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#342449 16-Jun-2010 20:48

I'm not too sure what you think your issue is - you have a perfect Telecom ADSL2+ connection.

24Mbps is a theoretical maximum only. Telecom's maximum is around 18kbps due to the noise targets they set on their network. Vodafone and Orcon both different noise targets which may deliver fractionally higher speeds but with the compromise of a potentially less stable connection.

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#342461 16-Jun-2010 21:46

sbiddle: I'm not too sure what you think your issue is - you have a perfect Telecom ADSL2+ connection.

24Mbps is a theoretical maximum only. Telecom's maximum is around 18kbps due to the noise targets they set on their network. Vodafone and Orcon both different noise targets which may deliver fractionally higher speeds but with the compromise of a potentially less stable connection.

So basically if your 800m away from the exchange and geting 18, then moving closer to it wouldnt improve your sync at all right? Or any wiring improvements in your house?

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#342526 17-Jun-2010 06:51

nickb800:
sbiddle: I'm not too sure what you think your issue is - you have a perfect Telecom ADSL2+ connection.

24Mbps is a theoretical maximum only. Telecom's maximum is around 18kbps due to the noise targets they set on their network. Vodafone and Orcon both different noise targets which may deliver fractionally higher speeds but with the compromise of a potentially less stable connection.

So basically if your 800m away from the exchange and geting 18, then moving closer to it wouldnt improve your sync at all right? Or any wiring improvements in your house?

It doesn't matter what your location is in comparision to the exchange or cabinet, any improvements over 18000 kbps would be very marginal. This is for all intent purposes roughly the maximum speed on ADSL2+
on Telecom.

If you were on an ULL exchange using Orcon or Vodafone you may get just on 20000 kbps but with (theoretically) a fractionally less reliable service due to the different noise level targets.

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#342554 17-Jun-2010 09:35

isn't 655 kbps upstream a bit low? I get higher than that and i'm around 2.5 kms from an ADSL1 exchange.

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#342574 17-Jun-2010 10:17

ADSL2+ theoretical max upload is 1.4Mbit/s. With the 12dB noise margins Telecom use (Orcon+ and Vodafone Red use 6dB) 650Kbit isn't bad.

It's possible that a master splitter/filter install could improve the upload line rate but no promises could be made.

If you're feeling rich try it and let us know how it goes!

PS: Does anyone know what noise margin Telstraclear and Slingshot are using by default on their gear installed in exchanges?

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#342745 17-Jun-2010 17:21

Hmm, I didn't realise that Telecom set noise margins. I wonder if its possible to request them to be slightly lower?

My sync rate increases (especially the upload) when I remove the filter on my BT plug. I can't keep it off for the time being as we need to use our telephone but I am hoping to change that by shifting to a naked DSL service.

Thanks for clarifying the sync issue, I assumed it should be better because I was so close.

On another note, could this count as false advertising on the part of Telecom? If they advertise a service they claim capable of up to 24Mbit/s* (*depending on line contitions of course); no matter how good my line conditions are I can still only ever sync at ~18Mbit/s so that seems to be a false advertisement and a misleading statement to me.

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#342799 17-Jun-2010 22:31

As far as I know Telecom wholesale do not offer lower than 12 dB noise margin. You can only get lower on other providers gear in the exchange (Orcon, Vodafone).

It does sound like a proper master spliter install might gain your some upload rate, let us know how it goes!

Some things to bear in mind about residential adsl:

All residential grade ADSL is a shared network best effort service with no guarantee of speed or performance.

Line rate is unlikely to be indicative of peak time performance for many ISP's unless the ISP has a huge amount of low usage users who hardly use the network (Telecom actually kind of fits this situation).

If an ISP has 1000 users on 10Mbit average sync rate they don't have 1000x10Mbit national and international capacity. Depending on the ISP capacity could be provisioned at 50:1 or 500:1 it's not public information.

Closest analogy is a motorway (still not a very good analogy), if you have 1000 cars going south at 8am you don't have a 1000 lane road.

If you want to see an idea of what the cost of "non shared" dedicated bandwidth have a look here:
http://www.xtreme.net.nz/connections/dedicated.php

1080p

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#343112 18-Jun-2010 19:47

Thanks for the information on dedicated bandwidth. I have run into this kind of information before but also realise its always relative; you can rent servers internationally with dedicated 100Mbit/s synchronous link speeds for ~NZ$100.00 per month. From my point of view it seems that we have a problem with too many middlemen for international link connectivity. We have suppliers purchasing directly from Southern Cross who in turn resell to other bandwidth suppliers/smaller ISPs and on to us.

/off topic

I'm probably going to go with a wiring and installation option and ask to have a master splitter installed. I can have this done for free with the ISP I am intending to sign up with within the next month so I will let you know how I fare.

Just to clarify, the wiring and installation option would mean a Chorus technician would come over and install the splitter and another telephone jack if I asked correct? Would he likely replace the old BT jack with an RJ45 jack or should I ask for this as well?

Is there somewhere detailing the mathematics involved in calculating sync rates based on noise margins etc? I am curious about how this is calculated and how it affects the line conditions. Where should I start reading?