My parents on FTTC 80/20 was sync at 56Meg at 6dB snr and then increase to 61Meg at 3dB (not much improvement) then soon later DLM decided to change their line due very bad crosstalk and over 500metres away drop their line to lower at 47Meg with snr 6.7dB. They actually downgraded to 40/10.

Edited by adslmax (Tue 30-Jun-20 23:11:37)

In reply to a post by sparky_paul:

Good info, thanks. I guess we'll find out who's right in due course

With regard to the SNR reducing to 3dB, is this likely to happen over the first two weeks, or are we talking over a longer period?

I remember my parents was on 6dB and G.INP enabled and it took 8 months for DLM to lower 3dB and stay there for few months then DLM say NO to 3dB and put their line back to 6.7dB with 47Meg. They had enough with FTTC 80/20 because their distance is over 500Metres away with Plusnet Hub One line attenuation at 15.7dB with badly crosstalk and downgraded to 40/10 FTTC.

I don't think crosstalk will be a major problem, there's only 20-odd properties on the cabinet, and some of those are still on ADSL, or phone line only.

I thought cross talk happened in the main on the cable bundle going to the cabinet? Thus I would have expected cable density to be the underlying factor.

Totally on a side note, sorry. If each house has a 5 pair cable, do all 5 pairs go back to the cabinet or just to the DP?

All the voice lines here are the original EO lines. I don't think the bundle going back to the exchange will be enormous, there's only 500 or so on the exchange in total, and they fan out in all directions.

In reply to a post by gary333:

Totally on a side note, sorry. If each house has a 5 pair cable, do all 5 pairs go back to the cabinet or just to the DP?

No problem, it's all interesting stuff.

In our case, there are two pairs in the drop wire from the pole, I would think only a single pair goes back from the pole connection box from each property, plus redundant spares. How many spares, your guess is as good as mine.

For subscribers cables that go underground, I don't know if the same cable would go right back to the PCP, or do they use local underground connection boxes? Interesting stuff.

The UG feed cable from outside the property will go as far as the nearest joint ..
so maybe not even as far as the DP.

In later years the 5pr cable has been replaced by 2pr

In reply to a post by Zarjaz:

The UG feed cable from outside the property will go as far as the nearest joint ..
so maybe not even as far as the DP.

In later years the 5pr cable has been replaced by 2pr

Ooh, interesting stuff. What is the purpose of a joint in an underground scenario, is it just to reduce line lengths to more manageable chunks? Or are they just there in scenarios where they don’t know how many properties are going to be erected / the time the builder is going to take so it allows dig outs to be filled, or something else?

Are the number of cables per property available all the way back to the cabinet, or is the number cut down at joint or DP. For example in my case there are 12 properties on a DP all with 5 pair. Would all 60 pairs go back?

The purpose of a joint in this scenario is to provide flexibility.

No, copper was expensive. If there are twelve properties on the DP, it most likely has a twenty pair feed. Even then, it is quite possible that not all twenty pairs go back to the cab. Each scenario is different.

Today's update. Something's happened overnight...

NEW STATS

DSL uptime:0 days,07 Hours19 Mins44 Secs
Data rate:19.999 Mbps / 73.953 Mbps
Maximum data rate:23.637 Mbps / 75.851 Mbps
Noise margin:15.4 / 5.3
Line attenuation:7.2 / 13.1
Signal attenuation:7.1 / 14.5
VLAN id:101
Upstream error control:Off
Downstream error control:Off

PREVIOUS (DAY 5)

Data rate:19.999 Mbps / 70.688 Mbps
Maximum data rate:25.118 Mbps / 72.268 Mbps
Noise margin:15.0 / 6.1
Line attenuation:7.3 / 13.1
Signal attenuation:7.2 / 14.6


Looks like 5dB SNR to me. Story so far...

Day 0 - Activation
Day 3 - Power cut!
Day 5 - G.INP switched on
Day 7 - SNR 6 >>> 5dB

Edited by sparky_paul (Thu 02-Jul-20 09:19:15)

In reply to a post by sparky_paul:

Today's update. Something's happened overnight...

NEW STATS

DSL uptime:0 days,07 Hours19 Mins44 Secs
Data rate:19.999 Mbps / 73.953 Mbps
Maximum data rate:23.637 Mbps / 75.851 Mbps
Noise margin:15.4 / 5.3
Line attenuation:7.2 / 13.1
Signal attenuation:7.1 / 14.5
VLAN id:101
Upstream error control:Off
Downstream error control:Off

PREVIOUS (DAY 5)

Data rate:19.999 Mbps / 70.688 Mbps
Maximum data rate:25.118 Mbps / 72.268 Mbps
Noise margin:15.0 / 6.1
Line attenuation:7.3 / 13.1
Signal attenuation:7.2 / 14.6


Looks like 5dB SNR to me. Story so far...

Day 0 - Activation
Day 3 - Power cut!
Day 5 - G.INP switched on
Day 7 - SNR 6 >>> 5dB

Look like your line are getting 80Meg soon. On your stats increase 3Mbps per 1dB snr reduced