Please explain to me VDSL speeds

Forums › New Zealand Broadband › Please explain to me VDSL speeds

Batman

Mad Scientist
29760 posts

Uber Geek

Trusted

Lifetime subscriber

#123463 8-Jul-2013 19:34

Hi - why does it take 2 weeks to get to top VDSL speed?

I am told to join telecom VDSL you need a copper ADSL attenuation of <10dB ...

Let's say you have a higher attenuation - why is it that you can't get good VDSL?

If the telecom check comes back as

lineAttenuation=10 - 12 dB
downloadRate=VDSL2: 15.6 - 17.3 Mb/s
uploadRate=VDSL2: 2.2 - 5.9 Mb/s

has anyone with first hand experience got reliable VDSL speeds after connecting with these speeds?

PeterReader

6018 posts

Uber Geek

Trusted

Geekzone

Lifetime subscriber

#851167 8-Jul-2013 19:34

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.

These links are referral codes: Sharesies | Mighty Ape

michaelmurfy

meow
13240 posts

Uber Geek

Moderator

ID Verified

Trusted

Lifetime subscriber

#851180 8-Jul-2013 19:43

It's an estimation, don't take it too seriously. Real world speeds depend on a heap of factors so that prequal is normally based off an overestimation of your attenuation along with a very rough estimation on speeds based off that. I'd say once you get a master filter installed it should be fine.

Michael Murphy | https://murfy.nz
Referral Links: Quic Broadband (use R122101E7CV7Q for free setup)

Are you happy with what you get from Geekzone? Please consider supporting us by subscribing.
Opinions are my own and not the views of my employer.

sidefx

3711 posts

Uber Geek

Trusted

#851199 8-Jul-2013 20:12

My attenuation on ADSL was 9, on VDSL it's 12 and I get 36/10. I think my prequal estimate was something like 19 down and I can't remember what up.... But yes, the prequal estimates seem extremely conservative.

It takes 10 days for the initial DLM period to complete. DLM (aka Dynamic Line Management) is a system where the stats\info\measurements for your line are continously collected and analysed and it changes parameters such as latency, INP, etc to tune the connection to your line. At a high level selects from a number of DLM profiles to do this. As that process progresses, generally speeds\sync rates seem increase and latency decreases. HAve a read of this post; some very good info applicable to all VDSL connections not just snap: http://www.geekzone.co.nz/forums.asp?forumid=90&topicid=105744

"I was born not knowing and have had only a little time to change that here and there." | Octopus Energy | Sharesies
- Richard Feynman

nitrotech

1285 posts

Uber Geek

#851207 8-Jul-2013 20:27

I know everyone says 10 days but I had no change of DLM for over 1 week then went from DLM 6 to DLM 4 then about 4 days after that to DLM 2 then another 4 or so days to DLM 1 more than 2 weeks for the whole process.

Speed didn't really change just the reduction in latency on DLM 1.

So while your profile may change your speed could very well stay the same.

sidefx

3711 posts

Uber Geek

Trusted

#851209 8-Jul-2013 20:29

The initial 10 day period is when it (supposedly) makes more frequent adjustments. But DLM profile changes can and will happen after that period. And yeah that pattern sounds pretty familar ^ :)

"I was born not knowing and have had only a little time to change that here and there." | Octopus Energy | Sharesies
- Richard Feynman