Tuning DSL line

Hello I have some question for you guys:

I have a 7M/512k DSL Line.

I have a c2651 with a WIC1-ADSL

since the port is limited at 7Mb (aal5 clockrate 7000000) I would like to train ADSL at a lower setting to gain some SNR.

My DSL currently trains at:

gw1.wisp#sh dsl int atm0/0 ATM0/0 Alcatel 20150 chipset information ATU-R (DS) ATU-C (US) Modem Status: Showtime (DMTDSL_SHOWTIME) DSL Mode: ITU G.992.1 (G.DMT) Annex A ITU STD NUM: 0x01 0x1 Vendor ID: 'ALCB' 'TSTC' Vendor Specific: 0x0000 0x0000 Vendor Country: 0x00 0xB5 Capacity Used: 83% 78% Noise Margin: 9.5 dB 14.0 dB Output Power: 20.0 dBm 11.0 dBm Attenuation: 20.0 dB 11.5 dB Defect Status: None None Last Fail Code: None Selftest Result: 0x00 Subfunction: 0x15 Interrupts: 2667 (0 spurious) PHY Access Err: 0 Activations: 2 LED Status: ON LED On Time: 100 LED Off Time: 100 Init FW: embedded Operation FW: embedded SW Version: 3.8131 FW Version: 0x1A04

Interleave Fast Interleave Fast Speed (kbps): 0 8128 0 640 Cells: 0 2090917 0 526470 Reed-Solomon EC: 0 0 0 0 CRC Errors: 0 0 0 0 Header Errors: 0 0 0 0 Bit Errors: 0 0 BER Valid sec: 0 0 BER Invalid sec: 0 0

Is it possibile to force the cisco to train at a lower speed ? something around 7000 ?

How can I work with some settings example dsl noise-margin xx ?

I haven't found a lot of documentations about dsl commands since they are unsupported.

Some hints?

Reply to
Elia S.
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Why? you seem to have zero corrected or uncorrected errors.. 9.5dB of SNR is fine.

Thats pretty clean. Most lines I see would have some corrected (ie. RS err) after a couple million of cells.

Not that I know of.

Reply to
Doug McIntyre

17 =A0 =A0 =A0 =A0 =A0 =A0 0 =A0 =A0 =A0 =A0 =A0 =A0526470

=A0 =A0 =A0 =A0 =A0 =A0 0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 0

=A00 =A0 =A0 =A0 =A0 =A0 =A0 0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 0

I agree.

My understanding is that the preferred speed is set at the upstream end. So, if you really, really wanted it to work less well than it is at present then you could try to persuade the provider to arrange the line to your requirements:-)

If you are on a mass-market connection you will not be able to achieve your required degredation but if you are paying more you might be able to.

Reply to
bod43

You have 9.5 dB SNR and then you want to gain some????

Why???

9.5 is very good. It is only at/below 6 dB that you need to start to worry.
Reply to
Rob

Hello this is the status after about 24h of connection:

gw1.wisp#sh dsl int atm0/0 ATM0/0 Alcatel 20150 chipset information ATU-R (DS) ATU-C (US) Modem Status: Showtime (DMTDSL_SHOWTIME) DSL Mode: ITU G.992.1 (G.DMT) Annex A ITU STD NUM: 0x01 0x1 Vendor ID: 'ALCB' 'TSTC' Vendor Specific: 0x0000 0x0000 Vendor Country: 0x00 0xB5 Capacity Used: 91% 79% Noise Margin: 7.5 dB 13.0 dB Output Power: 20.0 dBm 11.0 dBm Attenuation: 20.0 dB 11.5 dB Defect Status: None None Last Fail Code: None Selftest Result: 0x00 Subfunction: 0x15 Interrupts: 1333 (0 spurious) PHY Access Err: 0 Activations: 1 LED Status: ON LED On Time: 100 LED Off Time: 100 Init FW: embedded Operation FW: embedded SW Version: 3.8131 FW Version: 0x1A04

Interleave Fast Interleave Fast Speed (kbps): 0 8128 0 640 Cells: 0 524079500 0 136485561 Reed-Solomon EC: 0 0 0 0 CRC Errors: 0 99 0 0 Header Errors: 0 76 0 0 Bit Errors: 0 0 BER Valid sec: 0 0 BER Invalid sec: 0 0

Reply to
Elia S.

This is nothing to worry about.

When you want more margin, check if your provider supports ADSL2+ (G.992.5) and if so, upgrade your router to an ADSL2+ compatible type. Then you can get about 20 Mb/s on your line, and when using a 8 Mbit subscription you will have a lot more margin.

Reply to
Rob

Meanwhile, at the comp.dcom.sys.cisco Job Justification Hearings, Elia S. chose the tried and tested strategy of:

A particular noise margin shouldn't be an end in itself - unlike, say, trying to maximise your sync. My DSNM averages about 3.5dB and I use sensitive applications like VoIP with no issues. I even have lots of smokeping graphs to prove it.

What are you trying to achieve?

Reply to
alexd

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