Conductors on cabling preventing upgrade

[Juliass_M]

I have been busy with an upgrade of my 20mb VDSL to 40mb VDSL for past month or so, its been a long and tedious exercise and I'm about to give up.

From the outset I was told distance was a factor and when line tests were done I was testing that I am 1.3km from exchange. Meanwhile the entire loop measures at 770m, which is within the distance required for 40mb.

Today I received an email from the cabling division in my region changing their tune with regards to distance issue and placing the reason for being unable to do upgrade on a different issue all together.

"We measure the distance between your house and our equipment 793m but I don’t think distance is the problem here. Unfortunately a loss of speed occurs every time the conductor size changes and I belief that is what cause the problem. The network in your street was designed long ago with only voice services in mind. The underground cable will have 0.4 or 0.5 diameter conductors while the aerial cable will have 0.63 and the last wire to your house 1.25mm. Often from here you will get indoor cable again 0.5 or 0.63mm diameter. This unfortunately created several places where losses will occur. It is also not economical for Telkom to replace the copper network making it very difficult to improve the service currently."

This is inspite of my neighbour accross the road having an attainable rate of 69mbits and syncing at 40mb with brilliant SNR and attenuation stats.

Could anyone comment on reasoning provided by Telkom as a possible cause for issue as I do not have any engineering knoweledge.

 

[FNfal]

Post your line stats and let us look .
SNR particularly
But what they said about the copper seems right .
The voice network was never designed for ADSL.
The new copper is different to the old copper cabling

 

[Juliass_M]

============================================================================
VDSL Training Status: Showtime
Mode: VDSL2 Annex B
VDSL Profile: Profile 17a
Traffic Type: PTM Mode
Link Uptime: 3 days: 23 hours: 48 minutes
============================================================================
VDSL Port Details Upstream Downstream
Line Rate: 3.107 Mbps 33.248 Mbps
Actual Net Data Rate: 3.071 Mbps 33.198 Mbps
Trellis Coding: ON ON
SNR Margin: 12.9 dB 6.3 dB
Actual Delay: 0 ms 3 ms
Transmit Power: 7.2 dBm 14.5 dBm
Receive Power: -12.1 dBm -12.6 dBm
Actual INP: 0.0 symbols 0.0 symbols
Total Attenuation: 19.3 dB 27.2 dB
Attainable Net Data Rate: 6.402 Mbps 33.252 Mbps
============================================================================
VDSL Band Status U0 U1 U2 U3 D1 D2 D3
Line Attenuation(dB): 13.4 53.9 N/A N/A 26.8 65.9 102.3
Signal Attenuation(dB): 13.4 53.3 N/A N/A 26.7 65.7 N/A
SNR Margin(dB): 13.1 12.9 N/A N/A 6.4 6.2 N/A
Transmit Power(dBm): 1.2 5.9 N/A N/A 14.0 4.9 N/A
============================================================================

 

[Juliass_M]

Here is problematic bit, on news groups my download speeds fluctuate from 500kb/sec to 2 mb/sec, I will have to get them to downgrade this as my CRC errors are off the charts.

VDSL Counters

Downstream Upstream
Since Link time = 48 min 19 sec
FEC: 568597 0
CRC: 11223 124
ES: 2774 107
SES: 3 0
UAS: 0 0
LOS: 0 0
LOF: 0 0
LOM: 0 0
Latest 15 minutes time = 7 min 13 sec
FEC: 16855 0
CRC: 673 19
ES: 38 13
SES: 0 0
UAS: 0 0
LOS: 0 0
LOF: 0 0
LOM: 0 0
Previous 15 minutes time = 15 min 0 sec
FEC: 12025 0
CRC: 560 15
ES: 46 8
SES: 0 0
UAS: 0 0
LOS: 0 0
LOF: 0 0
LOM: 0 0
Latest 1 day time = 15 hours 52 min 13 sec
FEC: 89407 0
CRC: 2418 45
ES: 494 32
SES: 0 0
UAS: 0 0
LOS: 0 0
LOF: 0 0
LOM: 0 0
Previous 1 day time = 24 hours 0 sec
FEC: 139238 0
CRC: 1438 26
ES: 522 25
SES: 0 0
UAS: 0 0
LOS: 0 0
LOF: 0 0
LOM: 0 0
Total time = 1 days 15 hours 52 min 13 sec
FEC: 762294 0
CRC: 49174 192
ES: 3317 159
SES: 143 0
UAS: 820 820
LOS: 13 0
LOF: 40 0
LOM: 45 0

 

[Juliass_M]

Neighbours attenuation @ 40mb is 21 db downstream and SNR of 18 downstream

 

[FNfal]

Your SNR does not look great .

http://mybroadband.co.za/vb/showthread.php/186156-Understanding-SNR-and-Attenuation-Rates

I would down grade to 20 meg .

 

[Luke7777]

Don't think it's a question of downgrading or not.. the question is why is his neighbour accross the road, running thru the same conductors , is showing much better stats ? Maybe the last portion to the house is the problem. Maybe fire off a PM to TelkomZA for assistance

 

[Juliass_M]

Luke, it seems we only two people asking that question during this entire exercise. I replied to that email asking very same question and I've received no reply as of yet. Will try TelkomZA again.

 

[Tacet]

You and your neighbor (especially one who lives across the street and not next to you) might have very different copper in. Also, it sounds as though your line have a couple of joints in. Each joint will degrade your signal, even if soldered properly. A size-change in the cable means that the attenuation changes, which is another factor that will degrade signal.

 

[ponder]

Your neighbor across the road could be on a different feed.

 

[Luke7777]

@Tacet - They connect to the same MSAN , so up to a point they should be on the same copper. The people across from me only split away right at our respectives premises , hence my suggestion about the last portion to the house. Telkom's statement was also about 'the network in your street' , thereby including the neighbour.

 

[Juliass_M]

https://www.dropbox.com/s/wmpzdy40uolcune/MyBB%20Telkom%20upgrade%20map.png?dl=0

Here is path as described to me by cabling division I will give breakdown of distances from point A - D and description

A-B (Distance of cabling from router to Telkom pole) 60m
B-C (Distance from Telkom pole to street) 50m
C-D (Distance from house to exchange) 670m

Total distance 780m

Green blotch represents Telkom poles
Orange legend represents DP where lines come out ground.
Red dot represents path of cabling to MSAN.
Pink legend is neighbour.

The lines seem to run from DP to street and the follow trench to MSAN.

 

[Luke7777]

Neigbour feeding of same DP ?

 

[Juliass_M]

They have their own DP's on their side of street, the DP is actually in my yard.

 

[ponder]

They have their own DP's on their side of street, the DP is actually in my yard.

If your neighbor is on the other side of the street then they have their own feeder cable.

 

[Juliass_M]

My thing is to get someone out to isolate problem, but when they come out to test they bring a ADSL router to test on VDSL modulation.

Neighbour will have feeder cable I agree, but it will be similar in the fact that it too will be of a different thickness between the point of router to socket, socket to point where it is fed in home, to the point of DB and from DB to street and trench to MSAN.

With tests between MSAN and our DP they would see where drop off occurs but they say due to it being new technology they don't have the VDSL modem to test with. (usb powered routers, that don't require power outlets)

 

[Juliass_M]

Amazingly, after 5 faults reported and almost 2 months to the day. They sent technician to inspect cabling. He said solid cabling was used between Telkom pole and my phone jack. They should have installed a twisted pair which provides alot less interference.

Result im getting 40mbits sync after replacement of cable.

http://www.speedtest.net/my-result/4227947708

 

[Juliass_M]

My SNR improved drastically and so did my attenuation. Both by 10db

 

[Luke7777]

Maybe the last portion to the house is the problem

I rest my case

 

[Juliass_M]

Good call