ADSL connection with DLink GLB502T modem and Routertech 2.97

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Leo9
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ADSL connection with DLink GLB502T modem and Routertech 2.97

Post by Leo9 » Fri May 24, 2013 12:05 pm

Hi All,

Not sure if this is the right place to post this problem. I have recently flashed my DLink with the new firmware. I did this as the original firmware seemed a bit flaky. I have an ADSL, 16mbps connection. I have been facing frequent drops, one every 10 minutes.

The ISP checked stats and said SNR margin was too low, he did recrimping across all contacts and now the modem status is as below


Modem Status
Connection Status Connected
Ds Rate (Kbps) 16380
Us Rate (Kbps) 1021
DS Margin 18
US Margin 6
DS Line Attenuation 5
US Line Attenuation 5
Trained Modulation ADSL_2plus
LOS Errors 0
Peak Cell Rate 2408 cells per sec
CRC Rx Fast 0
CRC Tx Fast 0
CRC Rx Interleaved 0
CRC Tx Interleaved 0
Path Mode Interleaved

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

The ISP says this is fine and hinted at the modem having the problem. I have a couple of others which we tested with the same result, drops every 10 mins. ISP may now change the cable that terminates at our house from the junction box. In the meantime, can I carry out any tests which may indicate the root of the problem.

Thanks
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thechief
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Re: ADSL connection with DLink GLB502T modem and Routertech

Post by thechief » Fri May 24, 2013 1:52 pm

Post the output of the firmware's system diagnostics (see the "Tools" menu). You need to let the diagnostic run fully, and complete its task. This may take about a minute or so.
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Leo9
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Re: ADSL connection with DLink GLB502T modem and Routertech

Post by Leo9 » Fri May 24, 2013 3:44 pm

Hail to the chief. I am attaching the system diagnostics, for both while the connection is dropped and while connected. Also attached is the telnet dmesg output ( I think while the connection was dropped). I also tried downgrading the speed by changing mode to G.dmt and g.dmt.bis. The router did connect at a lower speed, but connection dropped in the same time frame.
system diagnostics.txt
(32.16 KiB) Downloaded 643 times
dmesg.txt
(6.69 KiB) Downloaded 598 times
Cheers
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thechief
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Re: ADSL connection with DLink GLB502T modem and Routertech

Post by thechief » Fri May 24, 2013 3:53 pm

There are inconsistencies in the diagnostic information. I think you need to run the diagnostic again - this time, when everything is running correctly.

Also, you need to defragment your environment, as it is badly fragmented. It is difficult to tell whether this is part of the problem until it has been sorted out.
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Re: ADSL connection with DLink GLB502T modem and Routertech

Post by Leo9 » Sat May 25, 2013 3:19 pm

Well Chief, i have tried to run sys diag while connected, but the connection would not sustain for more than 2-3 mins before it dropped and as the diagnosis takes longer to complete, it would always come up with no connection results.

In the meantime, I have forced the ISP to change all cables and pairs from the exchange to my house. They have done that, recrimped everything else and just now presto, I have a stable connection.

I defragged thru telnet, but what I have noticed is that; during the course of modifying the mode and consequent saves a couple of times, sys diag showed heavy fragmentation. Is this normal, should the bootloader fragment this rapidly?

I am attaching sys diag results from a few minutes back, while connection was on. I have also defragged just before running it.

Cheers
system diagnostics.txt
(15.31 KiB) Downloaded 563 times
PS: You always mention to remove sensitive information; have pored thru the diagnostics and haven't been able to identify something sensitive; other than maybe the IP address, but thats dynamic and will change.
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thechief
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Re: ADSL connection with DLink GLB502T modem and Routertech

Post by thechief » Sat May 25, 2013 4:09 pm

Good to know that the connection problem is sorted. With respect to fragmentation, each change to the environment is a potential cause of fragmentation. Some kinds of connection (e.g., pppoe) tend to write things to the environment regularly, so fragmentation is inevitable. As long as the fragmentation level is low (e.g., below 50), there should be no problem.
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Re: ADSL connection with DLink GLB502T modem and Routertech

Post by Leo9 » Sat May 25, 2013 5:47 pm

Thank you for your response. In the last hour the modem lost connection again. I have switched it with the other one that I have, which has not dropped the connection. Would you be able to look at the sys diag file and see that every thing is ok please.

Thanks once again.

Cheers
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Re: ADSL connection with DLink GLB502T modem and Routertech

Post by thechief » Sat May 25, 2013 7:31 pm

Leo9 wrote:Thank you for your response. In the last hour the modem lost connection again.
What you posted before shows no obvious issue. It would have been helpful to run the diagnostics immediately after the disconnection. You have a pppoe connection, and those can be problematic in all sorts of ways - but you also can't rule out the possibility that you are running the router at a faster speed than the line can manage. In order to rule that out, you can try selecting G.dmt modulation, and see if it improves things. You can also temper the connection speed to achieve greater reliability by running this at a telnet session

Code: Select all

setenv DSL_FEATURE_CNTL_0 0x03000000
/sbin/reboot
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