VDSL upload speed (higher than expected?)

beesboertjie

Senior Member
Joined
Jun 13, 2017
Messages
523
Measure the exact distance on GoogleEarth ...

Hi Winner. The downstream line attenuation of 26,5 dB means the length of your copper wire to the exchange is 1,9 km (1,2 miles). The Google Earth distance will always be shorter, it’s like the crow flies. By car I’m 500 meters from the exchange (by road), but my telephone wire is 800 meters long.
 

mercenary

Well-Known Member
Joined
Feb 21, 2006
Messages
135
Firmware Version:0.6.0 1.13 v0021.0 Build 160321 Rel.35486n
Hardware Version:TD-W9980 v1 00000001
System Up Time:6 day(s) 17:42:12
DSL
Line Status:Connected
DSL Modulation Type:VDSL2
Annex Type:Annex A
Upstream Downstream
Current Rate (Kbps) 8772 38694
Max Rate (Kbps) 8838 41887
SNR Margin (dB) 6.2 6.3
Line Attenuation (dB) 38.2 26.5
Errors (Pkts) 753 38


same sort of stats still. I do have SRA enabled and the sync speed does adjust up and down but only slightly.

i have done the numbers and in theory I should be lucky to sync at 20mbit but somehow its 38mbit ;)
 

ɹǝuuᴉM

Expert Member
Joined
Dec 6, 2015
Messages
3,604
I see. TX buddy. Well, for every 3dB increase in Line Attenuation you basically double the noise and in turn, half the data rate. You are on 26,5dB which should easy get you 20mbps with around 10db SNR Margin. Between 25 and 28dB one should get 20mbps (on VDSL2). The SNR Margin will differ though. At 25dB the SNR Margin should be just over 10dB and at 28dB Line Attenuation the SNR Margin should drop to 6dB. In your case the Margin is at 6.2dB. (Anything below 6dB is a No-Go). On the other hand, your download is not quite 40mbps! It look like something is doing the "balancing act" and is doing it well :) I am happy for you.
I know of another chap where his Line Attenuation is 29.5db (Down-Link) He too has a TP-Link modem (TD-W9980). His line sync comes on at 19mbit. SNR Margin is 6.5 and the error rate is marginally higher than yours. Actually he is a bit more "lucky" than you are.
With TP-Link modems it looks like, one can add one or two dB to the "Rule of Thumb".
 
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kaufen

Active Member
Joined
Apr 25, 2015
Messages
91
Ping: 19ms
Download: 39.98Mbps
Upload: 7.07Mbps
 
Last edited:

rh1

Executive Member
Joined
Aug 5, 2011
Messages
7,310
When the thread was created my upload was 4mb max. Now, whole weekend it has been 10mb. Did nothing on my side. In Table View.
 
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DrJohnZoidberg

Honorary Master
Joined
Jul 24, 2006
Messages
23,995
When the thread was created my upload was 4mb max. Now, whole weekend it has been 10mb. Did nothing on my side. In Table View.

Woop, just checked mine and it's also @ 10Mbps Up now (also in Table View).
 
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