Acceptable Adsl Line Noise/Attenuation?

[wpcoe]

I have a 3BB Premier 3Mbps/1Mbps package. When I lived in Jomtien (as recently has five days ago) my modem would report connect rates pretty close to 3072/1024. I just moved to Hua Hin and had the account transferred to my new home. I never show a connect above 2000/400, and wonder if it's a line problem, a setting at the 3BB office, or something else.

Below are the stats as reported by my router. Do the noise and attenuation seem within acceptable limits? I'm not sure what "Output power(dbm)" is, but is that figure okay?

I'm not sure how far I am from the DSLAM, but I'm about 100 meters from the main (Phetkasem) road, and only a five minute walk to the town center (the intersection with the road to the train station, if you are familiar with Hua Hin), so I don't think I should be too far from a DSLAM. The 3BB technician who ran the new line to my home spoke no English, and I can't explain what a DSLAM is in Thai. He did not recognize the written word "DSLAM".

If I get feedback that the noise/attenuation are okay, then I will contact 3BB to see if maybe they just have my account settings wrong in their computer configuration.

[Supernova]

Attenuation is good, but your noise margin is terrible. With your low attenuation (assuming it's accurate), you should be seeing SNR of at least 15dB ~ 20dB.

Check your internal wiring and make sure all line filters are in good condition. A bad 'splitter' can cause noise spikes, leading to low SNR. Also keep a close eye on the number of HEC/CRC errors reported in the router logs. If you're seeing lots of these in a short period of time, it's usually due to faulty wiring.

[lomatopo]

It looks like they may have (mis-)provisioned your line for 2 Mbps/512 Kbps?

The line looks pretty bad, you are ~ 1.5 Km from the DSL port card.

[Pib]

Your attenuation value is fine but your SNR is bad. Anything below a SNR 11db (i.e., 10, 9, 8, 7db....) will most likely cause modem sync/connection problems. This would cause your modem not connecting to the DSLAM at the package speed you are paying for and cause dropped internet/IP connections. See the following page for some ballpark Attenuation and SNR values. http://www.dslreports.com/faq/16220

Your low SNR valve could be caused by the line/junction boxes leading to your house (phone/ISP company's responsibility) or the line/connections within your house (your responsibility). Good luck.

[Pib]

It looks like they may have (mis-)provisioned your line for 2 Mbps/512 Kbps?

The line looks pretty bad, you are ~ 1.5 Km from the DSL port card.

How did you get this picture of TOT's & TT&T's joint international gateway?

[lomatopo]

It looks like they may have (mis-)provisioned your line for 2 Mbps/512 Kbps?

The line looks pretty bad, you are ~ 1.5 Km from the DSL port card.

How did you get this picture of TOT's & TT&T's joint international gateway?

It came from this article:

3BB Technician Suffers Near Fatal Electrocution in Pattaya

[wpcoe]

Thanks for all the feedback. In the next day or two, I'll walk down to the local 3BB office and discuss this with them. On my only visit to that office so far, I found them to be pleasant and knowledgeable. Good to have the info about SNR.

Since this is a dedicated ADSL line, I'm not using any splitter or filter.

They ran a new cable from a pole about 100m down the street directly to, and then into, my place. The technician took a cash payment of B640, and if I understood correctly it was B320 to bring the line to my exterior wall, and another B320 to bring the line inside and install a RJ11 jack. Could have been bogus charges, since no receipt was issued and I was not advised of the charges by the office, but I figured, what the heck.

It looks like they may have (mis-)provisioned your line for 2 Mbps/512 Kbps?

That was my initial thought, as well. I still think it might be the case, but will see what they say. AFAIK, there is no current 2Mbps plan, but like my grandfathered 3MBps Premier, there might still be some sort of plan like that in their system.

[Supernova]

It looks like they may have (mis-)provisioned your line for 2 Mbps/512 Kbps?

That was my initial thought, as well. I still think it might be the case, but will see what they say. AFAIK, there is no current 2Mbps plan, but like my grandfathered 3MBps Premier, there might still be some sort of plan like that in their system.

2M or 3M plan, it doesn't really matter. You need to get the low SNR problem resolved first. With downstream SNR in the single digits, you'll be lucky to achieve 2Mbps sync. And chances are it will get worse (if left unattended); you can trust me on this one as I've experienced the problem firsthand on a TOT line.

Edited April 2, 2011 by Supernova

[Pib]

The source of the problem is probably nothing more than a funky connection at numerous possible points between your house and the main junction box(es). There are so many places along a telephone/internet line where junctions can be made, such as right at your residence, where the line running to your house hooks into the main line on the pole, junction boxes along the way to the DSLAM/central station, etc. And if they have just strung one l....o....n.....g line from your residence to the nearest main junction box they could have spliced together several pieces of line leftover from other jobs...each splice point is just a connection point waiting to turn into a corroded/loose/poor connection point. A lot of the time the problem is at a main junction box that usually sets just above ground level and it's just a metal locker type box with hundreds of neighborhood connection points inside...connections inside are highly susceptible to corrosion, loose connection, etc. Sometimes when a technician works in the junction box to install a new line or fix another problem, they end up causing a problem for you because they slightly moved/touched your connection point which was already borderline in going bad. When these boxes are not sealed well from rain (and the ones I've seen don't seem to be), then water/rain intrusion can cause good connections to go from good to bad in a short period. Good luck...the technician shouldn't have a hard time finding the funky connection, especially if they have some basic testing devices/meters.

[lomatopo]

That was my initial thought, as well. I still think it might be the case, but will see what they say. AFAIK, there is no current 2Mbps plan, but like my grandfathered 3MBps Premier, there might still be some sort of plan like that in their system.

Are you experiencing any disconnects? Can you look at the router log? What type of router do you have?

In theory, with that noise margin you may be experiencing frequent disconnects, but perhaps not. Some routers (the DSL modem) can keep a decent lower-speed connection with that margin.

Any DSL port can be provisioned at almost any data rate, in 64 Kbps steps, this is independent of the 'packages' an ISP might offer. It is pretty easy for a port to be mis-configured, with a tech selecting 2,048 by accident (or misreading the work-order) instead of 3,072 and 512 Kbps instead of 1,024 Kbps.

[wpcoe]

Today flew right by and I didn't get a chance to visit the 3BB office. Hopefully on Tues or Wed?

It's a Belkin "Play Max" WiFi ADSL Modem Router. Once the modem connects, there doesn't seem to be any disconnects, but it DOES take SEVERAL attempts to make a connection when I power on (or reset) the modem. The norm when I lived in Jomtien was the modem would connect on the first attempt.

[wpcoe]

Hey, 3BB was up to the challenge!

I went to local 3BB office and the rep there verified that her computer showed me with 3Mb/1Mb Premier plan. She said technician would call & visit to follow up.

About two hours later a 3BB truck pulls up (guess he forgot to call me ), and after a test with his meter inside my house, he left for about 20 minutes, returned, replaced the outlet box (what do you call the thing with the RJ11 jack?) and when the router rebooted:

[Pib]

Good deal. When the technician left for 20 minutes I expect he went to a nearby junction box to do some testing and possibly switching of connections. If more people would do what you did in terms of checking to see if their ADSL modem sync speed, SNR, and Attenuation valves are good or bad; and then contacting the ISP armed with this info/detailed trouble report then they can usually get faster repair service since the trouble call-in has specific information as to what is probably causing the problem (i.e., bad sync speed, SNR, and/or attenuation) versus a general complaint slow speed, disconnects, etc. Hopefully your connection will stay good. Cheers.

[h90]

How this looks in compare on my connection?

noise margin upstream: 10 db

output power downstream: 13 db

attenuation upstream: 6 db

[Pib]

How this looks in compare on my connection?

noise margin upstream: 10 db

output power downstream: 13 db

attenuation upstream: 6 db

Output power downstream and Upstream Attenuation look fine, but your Upstream noise margin should be higher. You didn't provide the two most important values which are the downstream noise margin and sync speed. Wouldn't surprise me if the downstream noise margin is low since your upstream noise margin is low.

[h90]

How this looks in compare on my connection?

noise margin upstream: 10 db

output power downstream: 13 db

attenuation upstream: 6 db

Output power downstream and Upstream Attenuation look fine, but your Upstream noise margin should be higher. You didn't provide the two most important values which are the downstream noise margin and sync speed. Wouldn't surprise me if the downstream noise margin is low since your upstream noise margin is low.

This is what I now found:

noise margin downstream: 18 db

output power upstream: 10 db

attenuation downstream: 13 db

Connection: 11776 kbps / 874 kbps

I really have no idea what these number should tell me....

[Pib]

You probably have a 10Mb or 12Mb package based on the modem connection sync speed you reported. Your noise margin downstream is fine for this sync speed. I expect you experience few, if any, DSLAM" disconnects, although if your international web site surfing is many times show or you just can't seem to get an IP address, that probably due to your ISP's domestic and/or international gateway/bandwidth limitations during certain hours of the day/night (or all day/night). It's probably not due to any physical phone/internet line problem. If I had to guess, your ISP is True? Second guess would be 3BB. Third guess would be TOT.

[h90]

You probably have a 10Mb or 12Mb package based on the modem connection sync speed you reported. Your noise margin downstream is fine for this sync speed. I expect you experience few, if any, DSLAM" disconnects, although if your international web site surfing is many times show or you just can't seem to get an IP address, that probably due to your ISP's domestic and/or international gateway/bandwidth limitations during certain hours of the day/night (or all day/night). It's probably not due to any physical phone/internet line problem. If I had to guess, your ISP is True? Second guess would be 3BB. Third guess would be TOT.

It is 10/1 Mbit, true. What I noticed is that the upstream is not "full speed". when I connect my very old modem instead I get 8/1 (8 because the old modem has a maximum of 8 Mbit).