Line Syncing at 4mpbs, throughput only 0.5-1.5mbps

[fluKe]

Hi Guys,

Got ADSL installed in my place today.
4mb line, syncing to exchange at:
ADSL Link Downstream Upstream
Connection Speed 4096 kbps 512 kbps
Line Attenuation 7.0 db 3.5 db
Noise Margin 17.6 db 14.0 db

Speedtest.net:
http://www.speedtest.net/result/1332497096.png

Have tried on MWEB and Afrihost and I get similar results, what is going on?

 

[fluKe]

On MyBroadband speed test:

Download Speed: 802 kbps (100.3 KB/sec transfer rate)

Upload Speed: 425 kbps (53.1 KB/sec transfer rate)

Latency: 54 ms

 

[|tera|]

Which operating system? Do you have another pc or laptop to test with?

 

[fluKe]

Slow across all pc's in the apartment (All on Win7), tested at another location with this pc on 4mb adsl, and that works.

 

[Pada]

Something isn't right with your ADSL modem.

With those kind of Line Attenuation figures, you should get SNR margins well in the 20's if not 30's!

Try downloading like a relatively big file (50MB) from Microsoft/Nvidia/AMD with a download manager (eg. Free Download Manager), and then take the average speed.

 

[Slip]

<Deleted Post>

My bad got your line attenuation and SNR figures mixed up

 

[fluKe]

Your Line Attenuation and Noise Margin figures are bad.

This comes straight out of a previous post. Just search the forums

Line Attenuation.

Line attention is in relation to the "loop loss" on your line.
The further you are away from the exchange the higher your attenuation figure will be as the signal loss increases.
The lower your attenuation figure the more chance you have of getting the faster speeds.

SNR (Signal to Noise Ratio).

The SNR margin can only be measured from your own property and therefore to be measured correctly may need an engineer visit to check this figure from the BT test socket behind your master phone socket.Your SNR figure can fluctuate on a day to day basis and may vary depending upon local equipment, conditions and interference.
An upgrade in speed often causes the SNR to decrease by up to 5 dB.The higher your SNR figure then the better your line quality and therefore a higher chance of getting faster speeds.

Line Length.

Ideally your line length should be below 3.5km from the exchange to get a 2Mb connection.
At the present time the general public has no way of checking themselves this figure.
However, you may be able to get an indication by using Sams checker.


Downstream Attenuation

0-43 dB - 2Mbps
43-60 dB - 1Mbps
> 60 dB - 512kbps

Downstream SNR

Should be at least 10 dB to get adsl - ideally above 12dB.
Anything less than this will see frequent disconnections and other problems.

Did you read what you posted?

 

[Pada]

Did you read what you posted?

He probably didn't, because your line attenuation is outstanding, but your SNR margins are fairly poor if you take in consideration your synchronization speed & line attenuation values.

Your SNR margins are actually quite high, so you shouldn't have any stability issues with regards to your ADSL connectivity. So in your case your ISP account is most likely to be blamed.

 

[fluKe]

He probably didn't, because your line attenuation is outstanding, but your SNR margins are fairly poor if you take in consideration your synchronization speed & line attenuation values.

Your SNR margins are actually quite high, so you shouldn't have any stability issues with regards to your ADSL connectivity. So in your case your ISP account is most likely to be blamed.

Hi Pada,

I tested on 2 different ISPs. I am attempting to perform a firmware upgrade on the router, downloading at 5kb/s from Netgear.

 

[ichigo]

Hi Pada,

I tested on 2 different ISPs. I am attempting to perform a firmware upgrade on the router, downloading at 5kb/s from Netgear.

Are you using wireless or network cable to connect to your router. Plus noise margin is not the same as SNR Margin so your readings are perfectly fine.

When my old telkom router said 10's for Noise Margin my New routers said 20's for SNR Margins so they will change.

SNR Margin (0.1 dB): 302 260
Attenuation (0.1 dB): 80 35
Output Power (0.1 dBm): 73 121
Attainable Rate (Kbps): 11968 1188

My stats are quite similar to yours

So expect 27.6 and 24 for your SNR Margins with the newer router

Btw I am using TP-Link W8960N 300Mbps Wireless N ADSL2+ Router for R499
http://www.dbg.co.za/product_info.php?cPath=1_55_57&products_id=383

 

[fluKe]

Are you using wireless or network cable to connect to your router. Plus noise margin is not the same as SNR Margin so your readings are perfectly fine.

When my old telkom router said 10's for Noise Margin my New routers said 20's for SNR Margins so they will change.

SNR Margin (0.1 dB): 302 260
Attenuation (0.1 dB): 80 35
Output Power (0.1 dBm): 73 121
Attainable Rate (Kbps): 11968 1188

My stats are quite similar to yours

So expect 27.6 and 24 for your SNR Margins with the newer router

Btw I am using TP-Link W8960N 300Mbps Wireless N ADSL2+ Router for R499
http://www.dbg.co.za/product_info.php?cPath=1_55_57&products_id=383

Tested with LAN and WAN.

 

[ichigo]

Tested with LAN and WAN.

Must be your router giving problems then had same with my old one there were a few electrical surges which affected it so had to replace it.

But first try with your friends router on your line if you haven't already

 

[grim]

Noise Margin and SNR(Signal-to-Noise Ratio) are the same thing, just different terms. You're noise margins are quite low for the attenuation you're getting as Pada pointed out. It's probably the router that's got a issue somewhere or there could be a poor connection on the line somewhere but this is unlikely as your attenuation is very low.

My downstream attenuation at home is 15db and my SNR hovers around 29db on a 4Mb line.

Merenwenrago you're SNR went up with the new router cause it probably uses a better chipset than your old router.

 

[ichigo]

Noise Margin and SNR(Signal-to-Noise Ratio) are the same thing, just different terms. You're noise margins are quite low for the attenuation you're getting as Pada pointed out. It's probably the router that's got a issue somewhere or there could be a poor connection on the line somewhere but this is unlikely as your attenuation is very low.

My downstream attenuation at home is 15db and my SNR hovers around 29db on a 4Mb line.

Merenwenrago you're SNR went up with the new router cause it probably uses a better chipset than your old router.

Doesn't both Aztech router dsl600ew and Billion 400g use broadcom chipsets so how would that make a difference? Both showed downstream atten as like 26 and 5 for upstream. Only difference was the Noise Margin/SNR Margin.

I can understand with my TP-Link has better readings since it has an Atheros chipset

 

[fluKe]

Okay I've tested with another router and the problem persists.

 

[ichigo]

Okay I've tested with another router and the problem persists.

Have you tried using the router with everything unplugged (telephones/fax/pot filters) and could you check if your readings change or if the speed changes?

 

[callisto]

What is your packet loss ratio if you do a continuous ping with increasing payloads?

 

[ichigo]

Noise Margin and SNR(Signal-to-Noise Ratio) are the same thing, just different terms. You're noise margins are quite low for the attenuation you're getting as Pada pointed out. It's probably the router that's got a issue somewhere or there could be a poor connection on the line somewhere but this is unlikely as your attenuation is very low.

My downstream attenuation at home is 15db and my SNR hovers around 29db on a 4Mb line.

Merenwenrago you're SNR went up with the new router cause it probably uses a better chipset than your old router.

http://en.wikipedia.org/wiki/Noise_margin

Tells you exactly what it is. According to the explanation the router says minimum of 12 db for example it takes for connection to be stable so that = 0

Anything above 12 db if we using his stats shows 17.6 db and 14 db thus adding 12 db to them gives you the SNR Margin which is 29.6 db and 26 db for his line thus his margins are perfect for his attenuation.

Noise margins are generally defined so that positive values ensure proper operation, and negative margins result in compromised operation, or perhaps outright failure.

 

[grim]

Doesn't both Aztech router dsl600ew and Billion 400g use broadcom chipsets so how would that make a difference? Both showed downstream atten as like 26 and 5 for upstream. Only difference was the Noise Margin/SNR Margin.

I can understand with my TP-Link has better readings since it has an Atheros chipset

Nope the Aztech dsl600ew uses a Texas Instruments AR7 chip source:http://en.wikipedia.org/wiki/TI-AR7 I can't seem to find what chipset the Billion 400g uses.

 

[grim]

Consumer routers usually show the SNR Margin and not the SNR value regardless of the display name.
Depending on the manufacturer this may be "Receive Margin", "SNR", "Noise" or any variation of these.
It may also be abbreviated to SNRM or Noise Margin

Read more: http://www.kitz.co.uk/adsl/linestats.htm#SNR_Margin

My original post should've read: Noise Margin and SNR Margin(Signal-to-Noise Ratio Margin) are the same thing.