Future G.fast abilities based on VDSL stats

Hello all,

I'm lucky enough to live just down the road from my local VDSL cabinet - it's an ECI model (no G.INP or reduced thresholds for me!), but I'm still not complaining at 79987/20000 sync!

As I know there are a lot of people on here with better technical understanding of VDSL signal strength, attenuation and so on, I thought I might ask here regarding G.fast in the future. My area was upgraded to FTTC commercially, has had Virgin (ex-NTL) cable for over 20 years... it's pretty competitive and I can see it being upgraded to G.fast when that's rolled out more widely.

I've traced the path I think my line takes to the cabinet, and I believe it's about 180m, which would put it at the edge of some G.fast services, so I'd just like to know what others can extrapolate from my stats.

Here goes:

====================================================================================
VDSL Training Status: Showtime
Mode: VDSL2 Annex B
VDSL Profile: Profile 17a
G.Vector: Disable
Traffic Type: PTM Mode
Link Uptime: 0 day: 1 hour: 44 minutes
====================================================================================
VDSL Port Details Upstream Downstream
Line Rate: 20.202 Mbps 80.103 Mbps
Actual Net Data Rate: 20.000 Mbps 79.987 Mbps
Trellis Coding: ON ON
SNR Margin: 12.9 dB 8.9 dB
Actual Delay: 0 ms 0 ms
Transmit Power: - 6.4 dBm - 6.4 dBm
Receive Power: -10.2 dBm 4.5 dBm
Actual INP: 0.0 symbols 0.0 symbols
Total Attenuation: 0.0 dB 10.1 dB
Attainable Net Data Rate: 31.841 Mbps 91.380 Mbps
====================================================================================
VDSL Band Status U0 U1 U2 U3 U4 D1 D2 D3
Line Attenuation(dB): 0.1 9.0 14.6 N/A N/A 5.6 12.4 20.5
Signal Attenuation(dB): 0.1 8.9 14.5 N/A N/A 6.6 12.3 20.5
SNR Margin(dB): 14.7 13.3 12.6 N/A N/A 8.9 8.8 8.9
TX Power(dBm): -10.4 -41.3 -8.7 N/A N/A 10.5 7.3 7.4
====================================================================================

VDSL Counters

Downstream Upstream
Since Link time = 44 min 33 sec
FEC: 0 0
CRC: 0 0
ES: 0 0
SES: 0 0
UAS: 0 0
LOS: 0 0
LOF: 0 0
LOM: 0 0
Latest 15 minutes time = 1 sec
FEC: 0 0
CRC: 0 0
ES: 0 0
SES: 0 0
UAS: 0 0
LOS: 0 0
LOF: 0 0
LOM: 0 0
Previous 15 minutes time = 15 min 0 sec
FEC: 0 0
CRC: 0 0
ES: 0 0
SES: 0 0
UAS: 0 0
LOS: 0 0
LOF: 0 0
LOM: 0 0
Latest 1 day time = 1 hours 45 min 1 sec
FEC: 0 0
CRC: 0 0
ES: 0 0
SES: 0 0
UAS: 28 28
LOS: 0 0
LOF: 0 0
LOM: 0 0
Previous 1 day time = 0 sec
FEC: 0 0
CRC: 0 0
ES: 0 0
SES: 0 0
UAS: 0 0
LOS: 0 0
LOF: 0 0
LOM: 0 0
Total time = 1 hours 45 min 1 sec
FEC: 0 0
CRC: 0 0
ES: 0 0
SES: 0 0
UAS: 28 28
LOS: 0 0
LOF: 0 0
LOM: 0 0
====================================================================================

The reset, BTW, was due to IPv6 problems - not related to the line.

Thanks for any advice. (My cabinet, exchange etc. are in my signature).

I wonder why your line doesn't get the full 80 meg sync ???

I'm on an ECI cabinet too, also with a nice short line ......

Product name:
BT Hub 6A
Serial number:
+084316+NQ64206356
Firmware version:
SG4B10002244
Firmware updated:
30-Mar-2017
Board version:
1.0
Gui version:
1.32.0
DSL uptime:
10 Days, 18 Hours 47 Minutes 1 Seconds
Data rate:
20.00 kbps / 80.00 kbps
Maximum data rate:
19999 / 103537
Noise margin:
15.2 / 12.8
Line attenuation:
9.9


So some differences, but essentially you should be seeing the full kahuna.

(Oh, and no clue on the G.Fast question)

In reply to a post by Zarjaz:

I wonder why your line doesn't get the full 80 meg sync ???

I'm on an ECI cabinet too, also with a nice short line ......

Product name:
BT Hub 6A
Serial number:
+084316+NQ64206356
Firmware version:
SG4B10002244
Firmware updated:
30-Mar-2017
Board version:
1.0
Gui version:
1.32.0
DSL uptime:
10 Days, 18 Hours 47 Minutes 1 Seconds
Data rate:
20.00 kbps / 80.00 kbps
Maximum data rate:
19999 / 103537
Noise margin:
15.2 / 12.8
Line attenuation:
9.9


So some differences, but essentially you should be seeing the full kahuna.

(Oh, and no clue on the G.Fast question)

Surprised yours does not either!

Of all the information, this is probably all we can extrapolate from:

In reply to a post by pernickitypedant:

I've traced the path I think my line takes to the cabinet, and I believe it's about 180m,

=============================================
VDSL Port Details Upstream Downstream
Total Attenuation: 0.0 dB 10.1 dB
=============================================

I am currently on a line with attenuation of around 8.6dB, which is 100m in length, but is almost certainly 0.4mm copper ... so acts like 150m of standard length.

That's in line with your figures.

The current version of G.Fast hardware/firmware has been achieving 300Mbps at 150m, and 200Mbps at 200m in BT's trials.

However, there are plenty of amendments going into the G.Fast spec to improve speeds and range, so don't expect those numbers to be the final speeds. BT seems to have an aim for 300Mbps at 300m.

LOL
Good spot .

Great, that's good to hear. What's your attainable rate?

I'm slghtly annoyed that I can't make use of the full 31-34Mbit/s attainable upstream. What with other things going on I rarely see speeds over 17Mbit/s, which means it takes a while to upload weekly 1-hour 1080p YouTube videos!

Also, is CodeLook by Magenta Systems down for you too? I'm getting a "not found" error when I actually search... that would be very sad if permanent.

Don't forget that the G.Fast pod is being fitted directly to the PCP so that'll cut out upto 50m (some cases slightly more) from the existing DSLAM tie pair going to the FTTC cabinet.

FTTC (at least BT's vectorless variant) is not like adsl where you can read the attenuation and have a reasonable guess of the speed.

There is a huge lottery in crosstalk, and likely crosstalk is dictated by takeup in the area and cable type in the D side.

Some times people 300m away from the cabinet manage 80mbit down sync, and other times people 50m away dont manage it due to crosstalk. Short distance manipulates the odds but is no guarantee.

In reply to a post by unknown101:

Don't forget that the G.Fast pod is being fitted directly to the PCP so that'll cut out upto 50m (some cases slightly more) from the existing DSLAM tie pair going to the FTTC cabinet.

Can you explain how?

The G.fast pod is fixed directly to the PCP so the tie pairs to link it into the PCP will inly be in cm's, where as the FTTC cab can be up to 100m away, adding 100m to the VDSL citcuit length.