Not happy with sync

Cork981

Hi all just looking for some advice on my new VDSL2 connection with Vodafone.

I'm only syncing at 30/15 due to a low SNR

My line attenuation is nice and low so I should get a bit more that 30/15 what are the reasons for this ?

Connection Status
Help
DSL synchronization status Up
DSL up time 1 Days 06:12:38

Line Status
Help
Line standard VDSL2
Channel type
None
Downstream line rate (kbit/s) 32050
Upstream line rate (kbit/s) 15350
Downstream SNR (dB) 10.1
Upstream SNR (dB) 8.8
Downstream line attenuation (dB) 17.2
Upstream line attenuation (dB) 6.8
Downstream output power (dBmV) 11
Upstream output power (dBmV) 9.5
Downstream CRC 0
Upstream CRC 0
Downstream FEC 2775
Upstream FEC 419

ED E

Attenuation of less than 10dB is what I'd call low, you're 1200m or so from the DSLAM, 30 is a reasonable figure.

Deagol

ED E wrote: »

Attenuation of less than 10dB is what I'd call low, you're 1200m or so from the DSLAM, 30 is a reasonable figure.

ED, does attenuation purely indicate distance or could it also be noise from the line (my old bugbear of poor internal wiring etc)?

Cork981

ED E wrote: »

Attenuation of less than 10dB is what I'd call low, you're 1200m or so from the DSLAM, 30 is a reasonable figure.

Thanks, I'm fairly sure in my parents house my attention is about the same and I'm getting 70/20.


I'll have to double check this though.

ED E

Deagol wrote: »

ED, does attenuation purely indicate distance or could it also be noise from the line (my old bugbear of poor internal wiring etc)?

Its based on distance primarily, wire gauge can play a role in it. Faults can throw it off but usually not. If you put a DSL filter on the modem you'll see attenuation skyrocket *If* it manages to connect.

Crap internal cabling could increase the value disproportionately, eg. 100m of telecomms cable adds 1dB but 100m of bell wire adds 2dB (made up numbers). The antenna effect of internal wiring, earth faults, proximity to HFC/Mains etc is what will up the noise levels past whats expected.

Line capacitance is a better measure of loop length but only the far side has an MTAU to test that so you have to call in to get it (and most CSRs wont know what you're on about).

Cork981

ED E wrote: »

Attenuation of less than 10dB is what I'd call low, you're 1200m or so from the DSLAM, 30 is a reasonable figure.

Digging up this thread again.

Looking at this screenshot my DS attentuation is at 22.6 db and I regularly sync at 70/20.

This drops to 65 ish in the evening without a resync is this some form or Passive rate adoptive profile where my sync speed can dynamically change ?

Back to my first question..... I have a DS attentuation of 17 but a max sync of 30, why is this so low compared to the below attached connection?

BTW my attainable net rate jumps to 85 during the night and early morning.

ED E

I think Huawei are listing something different for "Total Attenuation", it seems to be a modulo sum of TP and RP. Having an electrical engineering degree would probably be handy here.

[May be completely wrong] Voice starts at the lowest end of the spectrum (near 0Mhz) and operates in a very narrow band. Just above that we have ISDN/ADSL operating in slightly bigger allocations but VDSL ranges all the way up to 12/17Mhz(and more) so attenuation varies more and depending on which carrier (subcarrier?) you measure from you'll get a different value. I'm not 100% clear on the rules for whats comparable to low band/capicitance. DS1 should be google says, but the above example says no.

It could just be dodgy firmware