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Standard User j3214
(newbie) Fri 04-Oct-13 16:31:02
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ADSL2+ questions


[link to this post]
 
Hello all!

I'm newly registered at the forum, but I've been viewing it for a long time prior to registering.

I have a few questions about ADSL2+ as I feel as if I'm not receiving the speed I should be, and I believe that I may have an issue.

I'm currently on 21CN WBC after switching from LLU.


First off, my line has a downstream attenuation of 38.5 dB (pretty reasonable I think) though it's only sync'd at a little over 7300 kbps at 6 dB fastpath. I've listed some of my line statistics below so I don't have to explain myself (as much), though I have omitted information about errors, data transfer and uptime (I can post them if it's really required, however I feel it's not).

DSL Type: ITU-T G.992.5
Bandwidth (Up/Down) [kbps/kbps]: 1.107 / 7.335
Output Power (Up/Down) [dBm]: 12,8 / 0,0
Line Attenuation (Up/Down) [dB]: 19,2 / 38,5
SN Margin (Up/Down) [dB]: 5,9 / 6,9
System Vendor ID (Local/Remote): TMMB / ----
Chipset Vendor ID (Local/Remote): BDCM / IFTN

Before uncapping the upstream, the downstream was over 7900 kbps.

Is it true that I should be able to receive a bit more than this?


Secondly, when the telephone is unplugged, the SNR drops by around 0.3-0.5, and of course when it's plugged back in it rises again, and I've tried two different telephones and there has been no change in results. Though I have noticed some minor crackling and noise on the line, but I don't know if it's worth flagging it up. I'm not sure if this is a sign of a bad filter, but I don't wish to disturb the DLM by messing with things as I've heard many stories about its destructive ways, especially during the training period.

I'm not sure how old the cabling is, but I'm sure both the cabling and socket are quite old.


Previously when on LLU (IFTN chipset at the exchange), the downstream attenuation was around 40.5-42 dB (quite variable for some reason), but speeds of 6800-7200 kbps were the normal at 6dB. There were instances where connecting at 7800 kbps (more or less) was possible, and once before more than 8800 kbps was possible, but slowly as the day progressed the connection dropped as the SNR tumbled and I've never seen such speed again.


I've linked an imaged of my bitloading graph here if someone would like to view it.

I think that's everything I need to ask.

Advice and answers would be highly appreciated.

Many thanks.
Standard User XRaySpeX
(eat-sleep-adslguide) Fri 04-Oct-13 17:06:29
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Re: ADSL2+ questions


[re: j3214] [link to this post]
 
You should be getting about 10 Meg sync @ 6dB NM.
In reply to a post by j3214:
Secondly, when the telephone is unplugged, the SNR drops by around 0.3-0.5, and of course when it's plugged back in it rises again
Have you tried this in the hidden test socket behind the faceplate? Are you saying you just pull the plug on the phone or are you reconnecting the router each time. Of course a change of 0.5 in a about 6dB NM is not usually significant.

1999: Freeserve 48K Dial-Up => 2005: Wanadoo 1 Meg BB => 2007: Orange 2 Meg BB => 2008: Orange 8 Meg LLU => 2010: Orange 16 Meg LLU => 2011: Orange 20 Meg WBC
Standard User yarwell
(sensei) Fri 04-Oct-13 17:12:14
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Re: ADSL2+ questions


[re: j3214] [link to this post]
 
for comparison

Uptime: 11 days, 21:12:10
DSL Type: ITU-T G.992.5
Bandwidth (Up/Down) [kbps/kbps]: 1.191 / 10.731
Data Transferred (Sent/Received) [MB/GB]: 729,24 / 1,65
Output Power (Up/Down) [dBm]: 12,7 / 0,0
Line Attenuation (Up/Down) [dB]: 20,5 / 40,0
SN Margin (Up/Down) [dB]: 5,0 / 3,1
System Vendor ID (Local/Remote): TMMB / ----
Chipset Vendor ID (Local/Remote): BDCM / IFTN

--

Phil

MaxDSL - goes as fast as it can and doesn't read the line checker first.

MaxDSL diagnostics


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Standard User j3214
(newbie) Fri 04-Oct-13 17:13:19
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Re: ADSL2+ questions


[re: XRaySpeX] [link to this post]
 
Thanks for the reply.

I haven't tried the test socket recently, but while on LLU I tried it and it made no noticeable different in sync (though I didn't monitor errors). I'm concerned that unplugging the router will affect the 10 day training period.

Also, I kept the router connected each time I disconnected phone.
Standard User j3214
(newbie) Fri 04-Oct-13 17:15:31
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Re: ADSL2+ questions


[re: yarwell] [link to this post]
 
In reply to a post by yarwell:
for comparison

Uptime: 11 days, 21:12:10
DSL Type: ITU-T G.992.5
Bandwidth (Up/Down) [kbps/kbps]: 1.191 / 10.731
Data Transferred (Sent/Received) [MB/GB]: 729,24 / 1,65
Output Power (Up/Down) [dBm]: 12,7 / 0,0
Line Attenuation (Up/Down) [dB]: 20,5 / 40,0
SN Margin (Up/Down) [dB]: 5,0 / 3,1
System Vendor ID (Local/Remote): TMMB / ----
Chipset Vendor ID (Local/Remote): BDCM / IFTN


That's a pretty good sync for 40 dB I think.

If my SNR gets reduced to 3 dB I don't think I will see stats anywhere near that; probably somewhere in the low 8000's seems likely.
Standard User XRaySpeX
(eat-sleep-adslguide) Fri 04-Oct-13 17:24:08
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Re: ADSL2+ questions


[re: j3214] [link to this post]
 
There's no harm in reconnecting occasionally as long as you don't overdo it, I switched router off overnight during the mythical training period.

1999: Freeserve 48K Dial-Up => 2005: Wanadoo 1 Meg BB => 2007: Orange 2 Meg BB => 2008: Orange 8 Meg LLU => 2010: Orange 16 Meg LLU => 2011: Orange 20 Meg WBC
Standard User j3214
(newbie) Fri 04-Oct-13 17:28:55
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Re: ADSL2+ questions


[re: XRaySpeX] [link to this post]
 
Uh oh... that can't be good:

Uptime: 0 days, 0:00:39
DSL Type: ITU-T G.992.5
Bandwidth (Up/Down) [kbps/kbps]: 1.112 / 4.107
Output Power (Up/Down) [dBm]: 12,8 / 0,0
Line Attenuation (Up/Down) [dB]: 19,3 / 39,0
SN Margin (Up/Down) [dB]: 5,7 / 6,9
System Vendor ID (Local/Remote): TMMB / ----
Chipset Vendor ID (Local/Remote): BDCM / IFTN

^ Plugged into the test socket.

Edit: Weird bitloading

Edited by j3214 (Fri 04-Oct-13 17:33:57)

Standard User eckiedoo
(member) Fri 04-Oct-13 17:41:32
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Re: ADSL2+ questions


[re: j3214] [link to this post]
 
Noting hat you can hear crackling, you should try the "Quiet Test".

Remove the faceplate to access the Test Socket.

Effectively, this should remove all local internal wiring, extensions etc - check that ALL are dead.

If any are still "live" ie you can hear dialling tone, then there may or may not be an (additional) problem with your internal wiring, which could be causing the noise.

Then plug in an ASDL Splitter/Dongle to the Test Socket.

Plug in to that dongle, the simplest (probably oldest) corded phone you have available.

Dial 17070

If it is a bundled SKY, select Option 4 (not sure of exact response to that as I am not on SKY)
or
for others, select Option 2. ("Response" should be a very quiet line, with "Quiet Test" spoken at intervals.)

If you still hear "snap, crackle and pop", tones, etc, first try with a different dongle.

If the noise/s continue, report that to your Phone Service Provider as a PHONE Fault, do NOT mention Broadband!

If your PHONE Line is not quiet/clean, your Broadband will almost always be degraded as well in some degree.

Some phone lines unfortunately may not have this Quiet Line Test facility.
Standard User David_W
(fountain of knowledge) Fri 04-Oct-13 17:49:48
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Re: ADSL2+ questions


[re: eckiedoo] [link to this post]
 
I agree completely with the proposed way ahead, except to note:

In reply to a post by eckiedoo:
Then plug in an ASDL Splitter/Dongle to the Test Socket.
Why bother? As you're not connecting an ADSL router, you can plug the phone directly into the test socket to start with.

If you hear noise, ideally repeat the test with another corded phone to make sure the problem isn't with the phone. If you don't have another corded phone to hand, don't worry too much. The idea is to eliminate as much as possible of your system when testing. If a defective filter was causing the crackling, you risk a charge for the engineer visit.

If no noise is heard with a directly connected corded phone, you can then try again with an ADSL microfilter in line. If you still hear no noise, connect the ADSL router to the microfilter, power it up and wait until it synchronises, then try the quiet line test again

In reply to a post by eckiedoo:
Some phone lines unfortunately may not have this Quiet Line Test facility.
The best option in those cases is to pick up the phone and dial a single digit. You should have a few seconds of quiet line before you get some sort of error (on BT WLR3 lines, typically a tri-tone followed by "the number you dialled has not been recognised...")

Standard User j3214
(newbie) Fri 04-Oct-13 17:55:45
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Re: ADSL2+ questions


[re: David_W] [link to this post]
 
Thanks for the replies people.

Unfortunately I cannot find a working corded phone, however even with the router connected and using a cordless phone while plugged into the test socket with the same filter nothing too significant comes up.

Though I'm a little concerned about my sync speed ever since plugging into the test socket. However the SNR has risen to 10 dB (downstream) since then.
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