Kitz Forum

Broadband Related => Telephony Wiring + Equipment => Topic started by: snadge on January 19, 2019, 04:19:32 PM

Title: Differences inside filters
Post by: snadge on January 19, 2019, 04:19:32 PM
I have seen some pictures and videos of the innard's of a filter and saw that some have just a few components, others have loads... so I thought I would open 2 of mine and one has twice the number of components compared to the other.

why is there such a difference in components? 
if they were to do the same job you would have thought they would all be very similar?


I wonder if ones with more components are any better/worse?

(https://i.imgur.com/aj9hSwt.jpg)
(https://i.imgur.com/ug8JN5X.jpg)
Title: Re: Differences inside filters
Post by: ejs on January 19, 2019, 05:51:51 PM
The ones with very few components were probably designed to be as cheap as possible with little regard for how well they work. Others may be designed to work properly.
Title: Re: Differences inside filters
Post by: snadge on January 19, 2019, 07:06:13 PM
i will test them over the coming days - i only like to have my line down no more than once per day just to keep DLM happy

Its wierd you mention that the ones with lesser components are likely cheaper (and probably less effective), as the one with lesser components is the one I was using previously and gave much better results than a Mk3 SSFP, I also saw a video in which the person in the video had 3 filters apart, 2 of them had many components and one was simple like the one above, yet he got much better results of his "cheaper" one too...
Title: Re: Differences inside filters
Post by: ejs on January 19, 2019, 08:00:16 PM
Yes well, if the only thing you want to connect to the line is the DSL modem, then no filter is required. The filter is to stop the DSL signal interfering with the telephones, and to stop the telephones interfering with the DSL. How was the performance of the filters evaluated? Speed, errors, stability, effects of using a telephone on the DSL? If you're not connecting any telephone, no filtering is needed.

I thought it was well known that the common mode noise filtering in the filtered faceplates sometimes caused a slight reduction in speed, probably due to attenuating the signal a little more. The Mk3 has a stronger filter than the Mk2. I guess it was decided that the faceplates were an overall benefit to the majority of lines, but all lines are different and what's best for one may not be what's best for another.

Maybe test the filters by plugging the modem into their phone outlet to see how much DSL signal they let through.
Title: Re: Differences inside filters
Post by: snadge on January 19, 2019, 08:07:35 PM
aye I think I will do that, I will try one method per day over the next few days or so

doesnt the modem drop sync without filters when someone tries to ring in?  or is that just when theres a phone on the other end of the incoming signal to receive it?, am I right in saying the incoming call comes with a slight voltage/power increase too?

I suppose it is sensible to expect a little bit of loss from any kind of RF filtering, espeically if you have TWO lol.. supposedly the Zyxel 8924 has one built in too... so thats TWO I have
Title: Re: Differences inside filters
Post by: ejs on January 19, 2019, 08:57:02 PM
Yes there will be some electrical changes happening on the line with an incoming call, but no, nothing should happen to the modem if the only thing connected is the DSL modem without any filters or telephones connected.
Title: Re: Differences inside filters
Post by: j0hn on January 20, 2019, 01:06:34 AM
I don't use a landline at all and find I get the highest sync/lowest errors with no filter at all.

I used to use a lower front plate that only had an rj45 port instead of the BT phone port.
I got it from AAISP for £6 but it appears to have vanished from their site so I guess they sold out.
Run-it-direct used to sell them also but I can't find them anywhere now.

I now use the standard NTE5A with the standard lower plate, but with my patch cable directly connected to the IDC's on the rear.
The modem in bridge mode is wall mounted next to this, with an RPi running stats powered from the modems USB port.
I've wanted this setup for a while and got round to it recently while decorating.
Will replace the NTE5A with a blank NTE5B eventually.
Picture attached.

Calling the landline has zero noticeable effect on my xDSL link.

edit: another alternative I forgot.
You can get a cable with a BT phone socket on 1 end and RJ11 port on the other, and use that with the standard faceplate.
Title: Re: Differences inside filters
Post by: snadge on January 20, 2019, 02:57:31 PM
I am doing that now, I have an RJ-11-to-BT-Phone converter fitted on the end of my RJ-11 cable, the sync is slightly higher than SSFP Mk3 but still a little shy compared to the dongle filter, mind they are all very similar and differences are negligible (79,000k-79,999k) ... but there none-the-less

I will monitor that stats an see if theres any difference
Title: Re: Differences inside filters
Post by: Weaver on January 21, 2019, 03:07:39 AM
I am now going like J0hn. I got some BT-to-RJ11 short cables and am using ordinary telephony front plates on some of my NTE5s; that is, front plates with just an ordinary BT telephone socket in them: plain phone-only, which non-DSL users have. I still have some of the AA DSL-only front plates as well, the ones J0hn has.
Title: Re: Differences inside filters
Post by: Jon21 on January 21, 2019, 08:52:07 PM
If I wanted to change from a filtered faceplate on a NTE5c, would I need:

1x https://www.run-it-direct.co.uk/bt-line-boxes-and-sockets/nte5cmastersocket/ for the phone only faceplate

1x https://www.run-it-direct.co.uk/adsl-vdsl-patch-leads/adslvdslbtcat5patchlead05m/

There isn’t a phone plugged in to the Mk4 faceplate, so if it may potentially improve sync/error rate, might give it a go.
Title: Re: Differences inside filters
Post by: burakkucat on January 21, 2019, 09:39:15 PM
Yes, that would be correct.  :)

However, please remember that there are other suppliers . . . so it is not necessary to just rely upon RID (https://www.run-it-direct.co.uk/).  ;)
Title: Re: Differences inside filters
Post by: Weaver on January 22, 2019, 04:55:11 AM
What Burakkucat said.

@Jon21 - thatís absolutely excellent. Itís what Iím doing now.

I got my cable from an eBay seller who was very good. You might just possibly see some slight improvement but donít be surprised if thereís a null result. These things are extremely difficult to measure (https://forum.kitz.co.uk/index.php/topic,15905.msg307641.html#msg307641). Fake effects just caused by the fact that you have resynched can override the result of measurements, when sync rates change anyway even though you have not changed any kit.

Shortening cables, using good quality modem-to-wallsocket cable, which should be CW1308 twisted pair (https://www.adslnation.com/support/cables.php), or Tandy/Adsl nation cable (https://www.tandyonline.com/high-speed-rj11-dsl-cable-0-5m.html), preferably extremely short as you suggested, these are very good things. I did get a substantial improvement by going from crappy modem-to-wallsocket cable to very high quality short twisted pair.

See https://forum.kitz.co.uk/index.php?topic=15910.0
https://forum.kitz.co.uk/index.php/topic,20119.0.html

[Moderator edited to fix a broken link.]
Title: Re: Differences inside filters
Post by: Jon21 on January 23, 2019, 01:12:57 PM
Received the faceplate and cable today.

Before:
Code: [Select]
VDSL Training Status:   Showtime
                    Mode:   VDSL2 Annex B
            VDSL Profile:   Profile 17a
                G.Vector:   Disable
            Traffic Type:   PTM Mode
             Link Uptime:   49 days: 17 hours: 2 minutes
====================================================================================
       VDSL Port Details       Upstream         Downstream
               Line Rate:     17.081 Mbps       75.735 Mbps
    Actual Net Data Rate:     17.058 Mbps       75.621 Mbps
          Trellis Coding:         ON                ON
              SNR Margin:        6.4 dB            6.5 dB
            Actual Delay:          0 ms              0 ms
          Transmit Power:        6.7 dBm          13.4 dBm
           Receive Power:      -12.2 dBm          -2.9 dBm
              Actual INP:        0.0 symbols       0.0 symbols
       Total Attenuation:        0.0 dB          19.5 dB
Attainable Net Data Rate:     17.632 Mbps       75.657 Mbps
====================================================================================
  VDSL Band Status        U0      U1      U2      U3      U4      D1      D2      D3
  Line Attenuation(dB): 8.9 31.4 47.0   N/A   N/A 14.1 35.4 55.6
Signal Attenuation(dB): 8.7 31.2 46.9   N/A   N/A 13.2 35.1 55.6
        SNR Margin(dB): 7.3 6.0 6.5   N/A   N/A 6.6 6.4 6.5
         TX Power(dBm): -3.6 -10.6 6.5   N/A   N/A 10.2 7.4 7.1
====================================================================================

After:
Code: [Select]
====================================================================================
    VDSL Training Status:   Showtime
                    Mode:   VDSL2 Annex B
            VDSL Profile:   Profile 17a
                G.Vector:   Disable
            Traffic Type:   PTM Mode
             Link Uptime:   0 day: 0 hour: 20 minutes
====================================================================================
       VDSL Port Details       Upstream         Downstream
               Line Rate:     18.179 Mbps       78.796 Mbps
    Actual Net Data Rate:     18.156 Mbps       78.682 Mbps
          Trellis Coding:         ON                ON
              SNR Margin:        6.0 dB            6.1 dB
            Actual Delay:          0 ms              0 ms
          Transmit Power:        7.0 dBm          13.3 dBm
           Receive Power:      -12.3 dBm          -2.9 dBm
              Actual INP:        0.0 symbols       0.0 symbols
       Total Attenuation:        0.0 dB          19.2 dB
Attainable Net Data Rate:     18.084 Mbps       78.689 Mbps
====================================================================================
  VDSL Band Status        U0      U1      U2      U3      U4      D1      D2      D3
  Line Attenuation(dB): 9.0 31.0 46.2   N/A   N/A 13.8 34.8 54.1
Signal Attenuation(dB): 8.8 30.8 46.1   N/A   N/A 13.0 34.6 54.1
        SNR Margin(dB): 7.1 6.0 6.0   N/A   N/A 6.2 6.1 6.1
         TX Power(dBm): -3.6 -11.0 6.5   N/A   N/A 10.0 7.3 7.4
====================================================================================

Bit of an increase in sync but not sure if that could be due to the drop in downstream attenuation of 0.3dB. Not sure if that could really give a 3Mb downstream increase and 1Mb upstream increase. Need more time to see if it's changed the error rate.
Title: Re: Differences inside filters
Post by: michty_me on January 23, 2019, 03:07:12 PM
I would normally see a 3Mb increase with a drop of around 1db for my line anyway.
I may have to try this little test also as I'm away to get my master moved and considering doing away with my home phone.
Title: Re: Differences inside filters
Post by: michty_me on January 25, 2019, 05:05:51 PM
Just as an experiment,I gave this setup a whirl to see if it made any noticeable difference on my line in terms of sync speed.

With MK4 filtered faceplate

Code: [Select]
adsl info --stats
adsl: ADSL driver and PHY status
Status: Showtime
Last Retrain Reason:    0
Last initialization procedure status:   0
Max:    Upstream rate = 16879 Kbps, Downstream rate = 70641 Kbps
Bearer: 0, Upstream rate = 16883 Kbps, Downstream rate = 70141 Kbps
Bearer: 1, Upstream rate = 0 Kbps, Downstream rate = 0 Kbps
Link Power State:       L0
Mode:                   VDSL2 Annex B
VDSL2 Profile:          Profile 17a
TPS-TC:                 PTM Mode(0x0)
Trellis:                U:ON /D:ON
Line Status:            No Defect
Training Status:        Showtime
                Down            Up
SNR (dB):        3.4             6.1
Attn(dB):        17.3            0.0
Pwr(dBm):        13.7            7.3

                        VDSL2 framing
                        Bearer 0
MSGc:           -6              21
B:              243             237
M:              1               1
T:              0               64
R:              10              16
S:              0.0000          0.4486
L:              18344           4530
D:              8               1
I:              254             127
N:              254             254
Q:              8               0
V:              0               0
RxQueue:                80              0
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G.INP Framing:          18              0
G.INP lookback:         20              0
RRC bits:               0               24
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MSGc:           154             -6
B:              0               0
M:              2               0
T:              2               0
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S:              6.4000          0.0000
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I:              32              0
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G.INP lookback:         0               0
RRC bits:               0               0

                        Counters
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OHF:            0               721524
OHFErr:         33              909
RS:             1710785272              2328937
RSCorr:         11785537                11774
RSUnCorr:       0               0
                        Bearer 1
OHF:            32696217                0
OHFErr:         0               0
RS:             326961556               0
RSCorr:         62              0
RSUnCorr:       0               0

                        Retransmit Counters
rtx_tx:         20912237                0
rtx_c:          124969          0
rtx_uc:         70              0

                        G.INP Counters
LEFTRS:         4               0
minEFTR:        70116           0
errFreeBits:    561826175               0

                        Bearer 0
HEC:            0               0
OCD:            0               0
LCD:            0               0
Total Cells:    2116626099              0
Data Cells:     298815713               0
Drop Cells:     0
Bit Errors:     0               0

                        Bearer 1
HEC:            0               0
OCD:            0               0
LCD:            0               0
Total Cells:    0               0
Data Cells:     0               0
Drop Cells:     0
Bit Errors:     0               0

ES:             14              844
SES:            0               0
UAS:            28              28
AS:             525273

                        Bearer 0
INP:            52.00           0.00
INPRein:        1.00            0.00
delay:          0               0
PER:            0.00            7.20
OR:             0.01            29.97
AgR:            70212.91        16912.51

                        Bearer 1
INP:            4.50            0.00
INPRein:        4.50            0.00
delay:          3               0
PER:            16.06           0.01
OR:             79.68           0.01
AgR:            79.68   0.01

Bitswap:        89035/89035             15053/15057

Total time = 6 days 1 hours 55 min 1 sec
FEC:            11785537                11774
CRC:            33              909
ES:             14              844
SES:            0               0
UAS:            28              28
LOS:            0               0
LOF:            0               0
LOM:            0               0
Latest 15 minutes time = 10 min 1 sec
FEC:            228             45
CRC:            0               2
ES:             0               2
SES:            0               0
UAS:            0               0
LOS:            0               0
LOF:            0               0
LOM:            0               0
Previous 15 minutes time = 15 min 0 sec
FEC:            456             29
CRC:            0               2
ES:             0               2
SES:            0               0
UAS:            0               0
LOS:            0               0
LOF:            0               0
LOM:            0               0
Latest 1 day time = 1 hours 55 min 1 sec
FEC:            2673            487
CRC:            0               24
ES:             0               23
SES:            0               0
UAS:            0               0
LOS:            0               0
LOF:            0               0
LOM:            0               0
Previous 1 day time = 24 hours 0 sec
FEC:            2347713         2204
CRC:            5               195
ES:             3               182
SES:            0               0
UAS:            0               0
LOS:            0               0
LOF:            0               0
LOM:            0               0
Since Link time = 6 days 1 hours 54 min 31 sec
FEC:            11785537                11774
CRC:            33              909
ES:             14              844
SES:            0               0
UAS:            0               0
LOS:            0               0
LOF:            0               0
LOM:            0               0
NTR: mipsCntAtNtr=0 ncoCntAtNtr=0
 >

Straight into the master connection without a filter

Code: [Select]
adsl info --stats
adsl: ADSL driver and PHY status
Status: Showtime
Last Retrain Reason:    0
Last initialization procedure status:   0
Max:    Upstream rate = 17729 Kbps, Downstream rate = 70517 Kbps
Bearer: 0, Upstream rate = 17733 Kbps, Downstream rate = 70577 Kbps
Bearer: 1, Upstream rate = 0 Kbps, Downstream rate = 0 Kbps
Link Power State:       L0
Mode:                   VDSL2 Annex B
VDSL2 Profile:          Profile 17a
TPS-TC:                 PTM Mode(0x0)
Trellis:                U:ON /D:ON
Line Status:            No Defect
Training Status:        Showtime
                Down            Up
SNR (dB):        3.4             6.0
Attn(dB):        17.2            0.0
Pwr(dBm):        13.7            7.3

                        VDSL2 framing
                        Bearer 0
MSGc:           -6              20
B:              243             237
M:              1               1
T:              0               64
R:              10              16
S:              0.0000          0.4271
L:              18458           4758
D:              8               1
I:              254             127
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RxQueue:                80              0
TxQueue:                20              0
G.INP Framing:          18              0
G.INP lookback:         20              0
RRC bits:               0               24
                        Bearer 1
MSGc:           154             -6
B:              0               0
M:              2               0
T:              2               0
R:              16              0
S:              6.4000          0.0000
L:              40              0
D:              3               0
I:              32              0
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RxQueue:                0               0
TxQueue:                0               0
G.INP Framing:          0               0
G.INP lookback:         0               0
RRC bits:               0               0

                        Counters
                        Bearer 0
OHF:            0               11287
OHFErr:         0               1
RS:             2786880         722287
RSCorr:         71              0
RSUnCorr:       0               0
                        Bearer 1
OHF:            4855            0
OHFErr:         0               0
RS:             47937           0
RSCorr:         0               0
RSUnCorr:       0               0

                        Retransmit Counters
rtx_tx:         20912450                0
rtx_c:          18              0
rtx_uc:         0               0

                        G.INP Counters
LEFTRS:         0               0
minEFTR:        70569           0
errFreeBits:    83951           0

                        Bearer 0
HEC:            0               0
OCD:            0               0
LCD:            0               0
Total Cells:    10585857                0
Data Cells:     2597            0
Drop Cells:     0
Bit Errors:     0               0

                        Bearer 1
HEC:            0               0
OCD:            0               0
LCD:            0               0
Total Cells:    0               0
Data Cells:     0               0
Drop Cells:     0
Bit Errors:     0               0

ES:             0               1
SES:            0               0
UAS:            27              27
AS:             79

                        Bearer 0
INP:            51.00           0.00
INPRein:        1.00            0.00
delay:          0               0
PER:            0.00            6.85
OR:             0.01            30.32
AgR:            70649.25        17763.74

                        Bearer 1
INP:            4.50            0.00
INPRein:        4.50            0.00
delay:          3               0
PER:            16.06           0.01
OR:             79.68           0.01
AgR:            79.68   0.01

Bitswap:        27/27           4/4

Total time = 1 min 46 sec
FEC:            71              0
CRC:            0               1
ES:             0               1
SES:            0               0
UAS:            27              27
LOS:            0               0
LOF:            0               0
LOM:            0               0
Latest 15 minutes time = 1 min 46 sec
FEC:            71              0
CRC:            0               1
ES:             0               1
SES:            0               0
UAS:            27              27
LOS:            0               0
LOF:            0               0
LOM:            0               0
Previous 15 minutes 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
Latest 1 day time = 1 min 46 sec
FEC:            71              0
CRC:            0               1
ES:             0               1
SES:            0               0
UAS:            27              27
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
Since Link time = 1 min 17 sec
FEC:            71              0
CRC:            0               1
ES:             0               1
SES:            0               0
UAS:            0               0
LOS:            0               0
LOF:            0               0
LOM:            0               0
NTR: mipsCntAtNtr=0 ncoCntAtNtr=0
 >
Title: Re: Differences inside filters
Post by: Jon21 on January 31, 2019, 04:34:19 PM
Need more time to see if it's changed the error rate.

Just to update, no noticeable difference in the error rate. Still getting ~ 10ES/hour on the downstream side. Was worth doing though for the increase in sync.
Title: Re: Differences inside filters
Post by: michty_me on January 31, 2019, 04:42:59 PM
I didn't notice much difference in my errors or downstream sync rate. I did gain 1mb on the upstream.
I've actually reverted back to my MK4 faceplate and gained 1mb on the DS. Probably to do with the time I rebooted the modem more than anything to be fair.