2 Phone #s, 2 ISPs, 2 ADSL Modems. Both ADSLs can't sync up at the same time.

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sync0

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I'm looking for any ideas that my help. We have the following set up;
  • 2 Phone Lines
  • 2 ADSL Filters
  • 2 ISP accounts - one with telkom and one with another ISP
  • 2 DSL Modems - Billion ADSL Modem/Routers
  • 0 Voice Lines active

When I connect each of the ADSL modems separately, they work with no issues. When I try and have both of them online at the same time, they constantly lose synch with one disconnecting the other and vice versa.

The demarcation point of the Telkom line to the house has a single white cable with 6 inner color-coded cables. The cables seem to be laid in parallel in the white casing. I pulled the white casing back a bit and did not see any twisted pairs.
One pair of cables feeds one phone line and the other the 2nd line. When I tested both modems at the demarcation point, the same thing happens where they lose synch if both connected or work well if only one is connected.

I have tried swapping out ADSL modems and using different ISP logins but the issue persists.

I got on the phone with Telkom and their ADSL tech tested both lines, and both tested ok so as far as they are concerned there is no issue.

Any ideas on what could be causing this or what I should do next?
Anyone out there successfully running 2 ADSL lines to their home or business? If so, are they both terminated by Telkom on the same physical cable?

Thanks in advance for any help I can get.
 
Post the line stats:

1. for one of the routers when it is the only one connected,
2. for both routers while both are connected.
 
DrJohnZoidberg said:
Post the line stats:

1. for one of the routers when it is the only one connected,
2. for both routers while both are connected.
Click to expand...

Thanks for your reply. Here are the stats:

Router 1 on Line 1 - Stand Alone
Upstream 1021 kbps
Downstream 7846 kbps
SNR Margin (Upstream) 7.3 db
SNR Margin (Downstream) 3.7 db
Line Attenuation (Upstream) 30.0 db
Line Attenuation (Downstream) 50.2 db

Router 2 on Line 2 - Stand Alone
Upstream 953 kbps
Downstream 5289 kbps
SNR Margin (Upstream) 9.0 db
SNR Margin (Downstream) 9.0 db
Line Attenuation (Upstream) 29.4 db
Line Attenuation (Downstream) 50.2 db


Both Routers Connected
Neither one of them Syncs Up. I get this on the modem/router:
DMT Status ADSL Down
Operational Mode ------------
Upstream 0 kbps
Downstream 0 kbps
SNR Margin (Upstream) N/A (ADSL is not UP)
SNR Margin (Downstream) N/A (ADSL is not UP)
Line Attenuation (Upstream) N/A (ADSL is not UP)
Line Attenuation (Downstream) N/A (ADSL is not UP)

If one is still connected while the other is trying to sync, it maintains the stats as posted above, before losing synch.
 
I'm pretty sure 2 physical lines with 2 different phone numbers. Both configured for DSL. 2 different ISP logins.

Trust me I have tested every possible setup combination.

ISP Account 1 + DSL Modem 1 works on both Telkom line A synching @ about 7Meg and also on line B synching @ about 5 Meg.

ISP Account 2 + DSL Modem 2 does the same synching as above.

Swapping out the ISP accounts on the modems results in syncs are the speeds above depending on the line connected to. Both ISP accounts are 10 MB Accounts.

If I plug an analog phone into either line and dial my cell phone I see 2 diff numbers. My Telkom bill has 2 numbers both configured for DSL.
 
Back in the day they used to be able to split one line for 2 voice lines, it would work for voice but not for dsl, maybe they did that with you.
 
OK looking at your individual line stats, your downstream attenuation is 50.2 db on both lines, which is pretty high. I don't think this is good enough to run the 7.8mbps and 5.3mbps lines and still achieve a stable connection. You should possibly ask them to downgrade your sync rate to 4mbps and 6mbps.

That said, from your description, it certainly looks like the 2 copper pairs (1 pair for each Telkom line) are interfering with each other. There could be a kink in the cable at some point, a lose connection, or a point where the 2 pairs are touching.

Phone Telkom again. Explain your problem in detail. Don't let them test each line individually. Connect 1 line, and they will see it syncing from their side. Then connect the second line, and they should be able to see the first line dropping, and the 2nd line unable to sync. This should be reason enough for them to come out and fix the problem. However, if they test the lines individually, it looks like they will always sync fine.

Now remember that all ADSL modems come with a built in filter, to filter out voice signals. So if you are only using your Telkom line for ADSL and nothing else, then there is no need for a filter. I would remove the filters, and connect the lines directly to the modems, and test again to see what happens.

I would also get 2 telephones, and connect both of them directly to the line, and disconnect the modems. Check if the quality of voice calls is clear on both lines. Pick-up the handset on both lines simultaneously, and make calls simultaneously as well. I think you will find problems with voice as well. If you do, you can then report it to Telkom as a problem with the voice lines. Don't tell them anything about ADSL, especially if they keep telling you there is nothing wrong. Rather report it as a fault with your voice services. Once that is sorted out, your ADSL should work fine again.

Once they do sort the lines out, I'm pretty sure your line stats will improve - your attenuation should drop, allowing you to connect at higher speeds to the exchange.

Good luck. Please let us know if and how you manage to resolve this problem.
 
Thanks for the replies and suggestions. I will get back on the phone with Telkom this week and report back.
 
Here is an update on the issue. It seems resolved .... for now.

  • Called Telkom to dispatch a tech
  • The tech tested from the demarc towards their network and said that a fault needed to be corrected on one of the lines. I did not get the details of what the issue was or what the fix entailed.
  • The tech came back the next day and tested again from the demarc to verify the issue was cleared. He then tested the inside wiring to the 2 DSL ports. The test showed issues with the lines. He inspected the cabling and said it needed to be replaced.
  • Another tech showed up, they confirmed that they were responsible for the internal wiring when the property was built. They re-ran cabling to the 2 phone jacks.
  • The tech connected both modems and both were synching up. I did not realize this, but it seems the tech worked with their call center to reduce the rate speed on both ports to 4MB

Both modems sync at 4094 down and 509 up. The connections have been stable for 4 days. I am using a multi wan router to load balance and provide redundancy, but have some services dedicated to either line.

I recently called Telkom to increase the port speed on one of the lines back to 10MB. They cautioned me that this may cause the lines to keep dropping again. They increased the speed and the line now synchs at 8MB down, 1MB up.

I will monitor the connection for a few days. If they remain stable I will keep it as is, if not I may have to roll the line back to the 4MB speed cap.
Perhaps I am just asking too much and should be content with 2 stable 4MB lines :)

Thanks again for all the pointers. They helped me have an informed discussion with Telkom.
 
sync0 said:
Here is an update on the issue. It seems resolved .... for now.

  • Called Telkom to dispatch a tech
  • The tech tested from the demarc towards their network and said that a fault needed to be corrected on one of the lines. I did not get the details of what the issue was or what the fix entailed.
  • The tech came back the next day and tested again from the demarc to verify the issue was cleared. He then tested the inside wiring to the 2 DSL ports. The test showed issues with the lines. He inspected the cabling and said it needed to be replaced.
  • Another tech showed up, they confirmed that they were responsible for the internal wiring when the property was built. They re-ran cabling to the 2 phone jacks.
  • The tech connected both modems and both were synching up. I did not realize this, but it seems the tech worked with their call center to reduce the rate speed on both ports to 4MB

Both modems sync at 4094 down and 509 up. The connections have been stable for 4 days. I am using a multi wan router to load balance and provide redundancy, but have some services dedicated to either line.

I recently called Telkom to increase the port speed on one of the lines back to 10MB. They cautioned me that this may cause the lines to keep dropping again. They increased the speed and the line now synchs at 8MB down, 1MB up.

I will monitor the connection for a few days. If they remain stable I will keep it as is, if not I may have to roll the line back to the 4MB speed cap.
Perhaps I am just asking too much and should be content with 2 stable 4MB lines :)

Thanks again for all the pointers. They helped me have an informed discussion with Telkom.
Click to expand...

6Meg is also an option. Works nicely with 4Meg uncapped accounts.
 
sync0 said:
Here is an update on the issue. It seems resolved .... for now.

<snip \>....

I recently called Telkom to increase the port speed on one of the lines back to 10MB. They cautioned me that this may cause the lines to keep dropping again. They increased the speed and the line now synchs at 8MB down, 1MB up.

I will monitor the connection for a few days. If they remain stable I will keep it as is, if not I may have to roll the line back to the 4MB speed cap.
Perhaps I am just asking too much and should be content with 2 stable 4MB lines :)

Thanks again for all the pointers. They helped me have an informed discussion with Telkom.
Click to expand...

It's a pleasure, and thanks for giving us feedback. Why don't you post the line stats for each line here? This will give a good indication of how stable your 10mbs line will be, and if the 4mbps line can be bumped up as well.
 
Here are my line stats:

I realize the SNR for the faster line is not ideal. The line has been stable, granted its been just one day.

I have been running an extended ping test out of both WAN interfaces and will review the stats after about 24 hours to assess the quality of both lines.

Line 1
Operational Mode ADSL2+
Upstream 1021 kbps
Downstream 7720 kbps
SNR Margin (Upstream) 7.3 db
SNR Margin (Downstream) 3.6 db
Line Attenuation (Upstream) 30.0 db
Line Attenuation (Downstream) 50.1 db

Line 2
Operational Mode ADSL2+
Upstream 509 kbps
Downstream 4095 kbps
SNR Margin (Upstream) 14.6 db
SNR Margin (Downstream) 11.4 db
Line Attenuation (Upstream) 29.6 db
Line Attenuation (Downstream) 50.6 db
 
Saajid said:
OK looking at your individual line stats, your downstream attenuation is 50.2 db on both lines, which is pretty high. I don't think this is good enough to run the 7.8mbps and 5.3mbps lines and still achieve a stable connection. You should possibly ask them to downgrade your sync rate to 4mbps and 6mbps.

That said, from your description, it certainly looks like the 2 copper pairs (1 pair for each Telkom line) are interfering with each other. There could be a kink in the cable at some point, a lose connection, or a point where the 2 pairs are touching.

Phone Telkom again. Explain your problem in detail. Don't let them test each line individually. Connect 1 line, and they will see it syncing from their side. Then connect the second line, and they should be able to see the first line dropping, and the 2nd line unable to sync. This should be reason enough for them to come out and fix the problem. However, if they test the lines individually, it looks like they will always sync fine.

Now remember that all ADSL modems come with a built in filter, to filter out voice signals. So if you are only using your Telkom line for ADSL and nothing else, then there is no need for a filter. I would remove the filters, and connect the lines directly to the modems, and test again to see what happens.

I would also get 2 telephones, and connect both of them directly to the line, and disconnect the modems. Check if the quality of voice calls is clear on both lines. Pick-up the handset on both lines simultaneously, and make calls simultaneously as well. I think you will find problems with voice as well. If you do, you can then report it to Telkom as a problem with the voice lines. Don't tell them anything about ADSL, especially if they keep telling you there is nothing wrong. Rather report it as a fault with your voice services. Once that is sorted out, your ADSL should work fine again.

Once they do sort the lines out, I'm pretty sure your line stats will improve - your attenuation should drop, allowing you to connect at higher speeds to the exchange.

Good luck. Please let us know if and how you manage to resolve this problem.
Click to expand...

This is very decent and helpful troubleshooting work! Well done
 
Hey sync0. Any feedback on your ADSL problems? Has it been fully resolved? Has your line been stable?

Please provide some feedback so that we can all learn from your problems.
 
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