DSLAM

[semaphore]

Hi,

The technician changed my port for me at the exchange as the port i was on had ****ty US and DS margins. Now that he changed it my line is only synching at 384, i phoned telkom adsl support they reset everything to the max speed, but it will still only synch at 384. Any advice how to get my line synching correctly 4096.

Thanks.

 

[fz1]

What are your noise margin and attenuation figures? Have they always been "****ty"? I don't think changing the DSLAM port will improve figures much (unless that port is somehow faulty) - they are determined by the quality and length of wiring to your house (from the exchange).

http://mybroadband.co.za/vb/showpost.php?p=1239914&postcount=7

 

[semaphore]

well what they done now is down graded me to the 1024 speed and its been perfectly stable, the copper to my house is brand new, newly laid cable. No noise or static that i hear on the line.

When is synching at 4096 my SNR DS is 13 US is 6 and Att is 46/ and something else cant remember

 

[fz1]

Attenuation of 46 is reasonably high, meaning you are reasonably far from your exchange. Although, I think downstream of 13dB when synched at 4096Kbps is perfectly acceptable. What are your figures when synched at 1024Kbps? And how about when you are synched at 384Kbps?

 

[semaphore]

When it synched at 4096 it dropped alot, it hasnt dropped being at 1024. Ill post my margins later, at 384 it was perfect.

Im 4km from the exchange. My neighbour has a 4mbit and he doesnt desynch.

 

[Mr_Kruger]

Im 4km from the exchange. My neighbour has a 4mbit and he doesnt desynch.

Do you know the cable route?
It could be more than 4km.

 

[Mr_Kruger]

Here a list of maximum possible bandwidth depending on line attenuation:

dB / kbps
≈ 14,8 18.000
≈ 17,5 17.500
≈ 20,1 17.000
≈ 23,4 16.500
≈ 25,8 16.000
≈ 26,5 15.500
≈ 27,0 15.000
≈ 28,3 14.500
≈ 29,1 14.000
≈ 30,5 13.500
≈ 31,2 13.000
≈ 31,7 12.500
≈ 32,2 12.000
≈ 33,4 11.500
≈ 34,0 11.000
≈ 34,9 10.500
≈ 35,4 10.000
≈ 36,3 9.500
≈ 37,0 9.000
≈ 38,5 8.500
≈ 39,2 8.000
≈ 40,2 7.500
≈ 41,5 6.500
≈ 42,7 5.500
≈ 44,5 4.500
≈ 47 3.500
≈ 50 2.500
≈ 55 1.500
≈ 60 500


4096kbps at 46 dB is very narrow...

 

[semaphore]

its been fine all day at 1meg, going to take it to 2meg and see how it handles

 

[semaphore]

Modem Status

Connection Status Connected
Us Rate (Kbps) 512
Ds Rate (Kbps) 1024
US Margin 14
DS Margin 13
Trained Modulation ADSL_G.dmt
LOS Errors 0
DS Line Attenuation 44
US Line Attenuation 25
Peak Cell Rate 1207 cells per sec
CRC Rx Fast 3
CRC Tx Fast 35
CRC Rx Interleaved 0
CRC Tx Interleaved 0
Path Mode Fast Path
DSL Statistics

Near End F4 Loop Back Count 0
Near End F5 Loop Back Count 0

 

[fz1]

Modem Status

Connection Status Connected
Us Rate (Kbps) 512
Ds Rate (Kbps) 1024
US Margin 14
DS Margin 13
Trained Modulation ADSL_G.dmt
LOS Errors 0
DS Line Attenuation 44
US Line Attenuation 25
Peak Cell Rate 1207 cells per sec
CRC Rx Fast 3
CRC Tx Fast 35
CRC Rx Interleaved 0
CRC Tx Interleaved 0
Path Mode Fast Path
DSL Statistics

Near End F4 Loop Back Count 0
Near End F5 Loop Back Count 0

These seem like decent figures to me. See if you can have your synch profile bumped up to 2MB...

 

[semaphore]

ill get them to bump it later when i get home and then see how it go's