How do ISP's determine estimate speeds for VDSL?

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solaybro

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#139064 26-Jan-2014 19:26

I have been looking into getting VDSL recently so I messaged Slingshot and Snap to do a pre-qualification and I was surprised by both responses. Snap said my lines attenuation is 1db and I should get a sync rate of 45Mbps+. Slingshot said that I could potentially get download speeds of up to 26.9Mbs and upload speeds of up to 13.6Mbps. What Snap say would be great but what Slingshot say would be better than what I have but it's kind of disappointing.

Whats with the huge difference?

Months ago I messaged Telstra/Vodafone to ask what my line attenuation is and I was told it was 3db up and 10db down so I don't know where Snap was getting their 1db from but that was months ago so maybe things have changed since then. I might ask them again since the only stats my router gives out is sync rates, I have the Linksys WAG120N.

If I message all the other ISP's that do VDSL will they all give me sync rates hugely different to each other?

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#974764 26-Jan-2014 19:26

Hello... Our robot found some keywords in your post, so here is an automated reply with some important things to note regarding broadband speeds.

If you are posting regarding DSL speeds please check that

- you have reset your modem and router

- your PC (or other PCs in your LAN) is not downloading large files when you are testing

- you are not being throttled by your ISP due to going over the monthly cap

- your tests are always done on an ethernet connection to the router - do not use wireless for testing

- you read this topic and follow the instructions there.

Make sure you provide information for other users to help you. If you have not already done it, please EDIT your post and add this now:

- Your ISP and plan

- Type of connection (ADSL, ADSL2, VDSL)

- Your modem DSL stats (do not worry about posting Speedtest, we need sync rate, attenuation and noise margin)

- Your general location (or street)

- If you are rural or urban

- If you know your connection is to an exchange, cabinet or conklin

- If your connection is to a ULL or wholesale service

- If you have done an isolation test as per the link above

Most of the problems with speed are likely to be related to internal wiring issues. Read this discussion to find out more about this. Your ISP is not intentionally slowing you down today (unless you are on a managed plan). Also if this is the school holidays it's likely you will notice slower than usual speed due to more users online.

A master splitter is required for VDSL2 and in most cases will improve speeds on DSL connections. Regular disconnections can be a monitored alarm or a set top box trying to connect. If there's an alarm connected to your line even if you don't have an alarm contract it may still try to connect so it's worth checking.

I recommend you read these two blog posts:

- Is your premises phone wiring impacting your broadband performance? (very technical)

- Are you receiving a substandard ULL ADSL2+ connection from your ISP?

I am the Geekzone Robot and I am here to help. I am from the Internet. I do not interact. Do not expect other replies from me.

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johnr

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#974774 26-Jan-2014 19:30

Upload 13.6Mbps does not sound right but the INFO generally comes from Chorus

If yiu want VDSL and can get it just order it stop the mucking around

solaybro

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#974778 26-Jan-2014 19:36

johnr: Upload 13.6Mbps does not sound right but the INFO generally comes from Chorus

The info I have been given seems highly unreliable especially from Snap. I expect better download speeds from Slingshot though since I am 130m from the cabinet.

johnr

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#974780 26-Jan-2014 19:40

Check out the Chorus map and at that distance speed is going to be far better up and down over ADSL2+

PoHq

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#974781 26-Jan-2014 19:43

I'd just go ahead and order it, it's going to be considerably better than any ADSL service. As you are only 130m away you should be hitting the upper end of VDSL limits.

plambrechtsen

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#974782 26-Jan-2014 19:46

All prequals come out of the Chorus system
So perhaps they were reading it differently. Plus your own isp can run a line test against your current ADSL connection to get the most accurate value.

solaybro

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#974784 26-Jan-2014 19:49

PoHq: I'd just go ahead and order it, it's going to be considerably better than any ADSL service. As you are only 130m away you should be hitting the upper end of VDSL limits.

I do plan on ordering, I was just curious what was up with the difference and whether Snap can actually give me those speeds.

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nickt

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#974785 26-Jan-2014 19:51

salaybro, you should be able to visit /setup.cgi?next_file=adsl_driver.htm on your LinkSYS to get attenuation info for ADSL. Might change a bit if you need to get a master splitter installed for VDSL.

In the top post in the VDSL Performance & Tuning thread there are some mappings and a graph for attentuation to sync.

solaybro

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#974787 26-Jan-2014 19:57

nickt: salaybro, you should be able to visit /setup.cgi?next_file=adsl_driver.htm on your LinkSYS to get attenuation info for ADSL. Might change a bit if you need to get a master splitter installed for VDSL.

In the top post in the VDSL Performance & Tuning thread there are some mappings and a graph for attentuation to sync.

I still can't view my stats. It takes me to a page where the stats should be but no numbers are displayed. I have googled where to find them on my router before and after reading many forums I have found that my router just doesn't display stats, many people have this issue.

johnr

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#974788 26-Jan-2014 19:58

Just move to VDSL then and get a new modem

sidefx

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#974794 26-Jan-2014 20:07

I honestly wouldn't bother agonizing over what speed you "might" get.

All the estimates for speed come from data held by chorus - they calculate an estimate for attenuation AND speeds based on line data collected in the past. BUT their speed estimates seem to be extremely conservative so I would guess snap are using their knowledge of VDSL (they have been offering VDSL for a lot longer than most of the bigger players) to estimate likely speed from the chorus attenuation figure whereas slingshot are perhaps just quoting the straight chorus speed estimates? Either way they're all just estimates. Looking at ADSL attenuation won't give you a definite answer either since it changes when you switch to VDSL (higher frequencies) and if you don't have a master splitter they will install one which could also make a difference.

At the end of the day I'm firmly of the opinion that if a prequal says you can get VDSL, you absolutely should. Stop procrastinating and just do it man! :P

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solaybro

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#974798 26-Jan-2014 20:20

At the end of the day I'm firmly of the opinion that if a prequal says you can get VDSL, you absolutely should. Stop procrastinating and just do it man! :P

Who would you recommend I join? I'm looking at Snap and Slingshot.

hio77

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#974804 26-Jan-2014 20:33

solaybro:
At the end of the day I'm firmly of the opinion that if a prequal says you can get VDSL, you absolutely should. Stop procrastinating and just do it man! :P

Who would you recommend I join? I'm looking at Snap and Slingshot.

slingshots prequal is wrong for the upload.. as you will max out at 10mbit regardless.

as you are 130M (which on adsl would equate to close to a 1~2db bracket) your in extremely good running for a 17a profile - which would likely put you in the 55~70mbit mark..

ild personally recommend snap, they have been doing vdsl for quite some time now, and know exactly what they are doing. slingshot on the other hand are dealing with firmware bugs with their vdsl modem currently. (i also wouldnt personally touch them with a 10ft pole.. but that seems a little more personal to myself about quality of service provided..)

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sidefx

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#974805 26-Jan-2014 20:33

solaybro:
Who would you recommend I join? I'm looking at Snap and Slingshot.

I'm with snap for VDSL and have been for almost 2 years now - I have no hesitation in recommending them. They have changed their pricing\data caps\etc a couple of times since I joined and they always seem to pass the improvements on to existing customers, even on contract. This for me was a real breath of fresh air. I also really like the ability to login to their website at any time of the month and change data pack add-on to a different one or even remove it. And their zero-rating of data from 1am-7am if you have a data pack is pretty much just as good for me as an unlimited ISP (without all the issues that seem to come up with real unlimited offerings)

The only thing that seems to be a bit of an issue with snap for a while is that they perhaps need to work on their communications processes with new customers. Their helpdesk always seems excellent though, so just call them during the signup process and to confirm go-live dates, etc.

I can't really speak much about slingshot as I've never been with them.

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Sideface

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#974812 26-Jan-2014 20:39

sidefx: ... All the estimates for speed come from data held by chorus ... Either way they're all just estimates. Looking at ADSL attenuation won't give you a definite answer either ...

Estimates are only estimates.
I was recently provided with VDSL with a full Chorus install - VDSL master filter, Cat6 cable, J45 port, new VDSL modem ...
Prequal estimate was 20+/9.5 down/up.
I got 13/4 :(
I'll try to go back to ADSL after the 10-day learning/training period is over.
[The name of my ISP is withheld - but it was not Snap or Slingshot]

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