New FTTC connection slower than expected

To start with some background, I've helped my parents move away from Virgin Media because of the price increases. They wanted to find a cheaper provider, and they were willing to take a hit on the speed as they are light users.

I've helped them switch over to Vodafone's FTTC service. Ever since they moved into their current house 12 years ago, they have been on VM, and therefore the BT line has remained dormant for that time. I was only able to order the 35/10 package to the house - BT Wholesale availability checker confirmed that their max speed is 35/7.

I was quite surprised as their local cabinet (ECI) is 400 m as the crow flies, and the Openreach engineer who performed the install told me that the cable length to the cabinet was 500 m. Looking at the VDSL/distance graph, the property should be capable of 60 Mbps down. Why is the maximum speed capped at 35 Mbps? I don't think poor cabling is the issue as the estate was constructed in the 80s. Would this be down to the local cabinet being oversubscribed?

The new line has been active for just over 24 hours at this point. I understand it takes a few days for DLM to adjust the parameters of the line to bring it up to speed, but it's currently stuck at the bottom of the "VDSL Range B" from the wholesale availability checker (25D/4U).

Current line stats from the VF THG3000 router (currently connected directly in to the master socket w/ MK4 faceplate):

Text

1 23 45 67 89 1011 1213 1415 1617 1819 2021 2223 2425 2627 2829 30

Line Quality         Downstream      UpstreamCurrent Rate    26671 kbps      5403 kbps Maximum Rate    32560 kbps      5454 kbpsSignal-to-Noise Ratio   6.2 dB  6 dB Attenuation     DS1 17.4 dB, DS2 51.6 dB, DS3 80.1 dB   US0 7.1 dB, US1 41.3 dB, US2 62.3 dBPower   11.4 dBm        3.5 dBm CRC Errors in last 1330 minute(s)       61      12K (number of bytes in DMT frame)        0       0 R (number of bytes in RS code word)     12      16S (RS code word size in DMT frame)      0.0620  0.9993 D (interleaver depth)   523     1Delay   8 ms    0 ms         Downstream      UpstreamSuper Frames    20041427        4917701 Super Frame Errors      61      12RS Words        835574522       319579810 RS Correctable Errors   60101   57RS Uncorrectable Errors         5126    0         Downstream      UpstreamHEC Errors      1106    0 OCD Errors      0       0LCD Errors      0       0 Total Cells     4095850016      0Data Cells      40360800        0 Bit Errors      0       0        Downstream      Upstream Total ES        15      7Total SES       0       0 Total UAS       25      798047

Edited by scrlk (Mon 31-Aug-20 14:03:45)

The difference between Vodafone's Superfast 1 & 2 is *usually the VDSL2 mode used at the cabinet. So for SF2 it's mode 17A and for SF1 it's mode 8A. So even if the connection speed for a mode17a connection at the premise is greater than the mode8a maximum, you'll not hit that maximum.
As for why you can't can't even order SF2 at your address there are many reasons. I'm on a new build estate and have VF SF2, but if you check the address now, SF1 is the maximum that's available - and there is a waiting list due to the cabinet being oversubscribed.

*There are VF SF1 customers who have managed to complain hard enough that their connection has been upped to mode17a - but good on that!

Openreach haven't used 8a for a long time , its all 17a in FTTC regardless of whatever wholesale speed tier is selected

I've just done a bit of investigation. Houses on the opposite end of the estate share the same cabinet, but the distance is a lot shorter (sub 50 m as the crow flies). BTW and VF says they can order SF2 / 80/20 package.

I guess if over-subscription was the problem, no one connected to the cabinet could order SF2? I'm not too clued up on how this works, but could one half of the estate be connected to a heavily utilised line card and the other half on a quieter one, explaining why I can't order SF2 whereas others can?

Faulty card or associated wiring notwithstanding, bandwidth capacity is shared across all cards in the cabinet. It seems your line just cannot manage higher speeds. Changing to a different speed tier will not change that.

In reply to a post by scrlk:

I was quite surprised as their local cabinet (ECI) is 400 m as the crow flies, and the Openreach engineer who performed the install told me that the cable length to the cabinet was 500 m. Looking at the VDSL/distance graph, the property should be capable of 60 Mbps down. Why is the maximum speed capped at 35 Mbps? I don't think poor cabling is the issue as the estate was constructed in the 80s. Would this be down to the local cabinet being oversubscribed?

Does the cable between the home and the cabinet have any aluminium in it? A lot of 1980s build does. Is there an NTE5 master socket, or do you have lots of phone points in the property, put in by the builders? Often the builders installed cheap bell wire for phone points, and disconnecting these can improve matters (a proper NTE5 master socket will do this disconnection for you).

Aluminium cables - not sure on that point, forgot to ask the OR engineer when he came around for the install. That's probably the cause of the slow speed then. Looks like there's going to be a long wait until FTTP rolls out if they don't want to go back to VM...

I disconnected and removed all of the old and unused extensions before the install. OR replaced the LJ3/1a master socket with a new NTE5c + MK4 faceplate. As the master socket is inconveniently placed in the hallway by the front door, I plan to install a voice + data extension with some quality solid copper Cat5e in the near future so that the router can live in a more convenient location.

In reply to a post by CrimsonOne:

The difference between Vodafone's Superfast 1 & 2 is *usually the VDSL2 mode used at the cabinet. So for SF2 it's mode 17A and for SF1 it's mode 8A. So even if the connection speed for a mode17a connection at the premise is greater than the mode8a maximum, you'll not hit that maximum.

No idea where you get that from.

OpenReach launched FTTC with VDSL2 profile 8a but shortly after they upgraded to profile 17a. The cards already supported 17a.

They haven't used profile 8a since 2012.

It's much easier to use profile 17a for all lines and rate limit the sync speed at the DSLAM for slower tiers than it is using a mix of 8a/17a.