ADSL Nightmare

[Noema]

I have a 1mbps ADSL connection at home. It's not the fastest in the world but it's enough for my needs.

That said, performance has been getting gradually worse since about 5 weeks ago. Not to mention I get dropped with certain frequency and I must manually reconfigure some of the PPPoE settings.

It all started when one day I noticed down speeds where much worse than usual. I have an average download speed of about 120KB/s. Instead, I was getting speeds of 34ish up to 50KB/s, regardless of the server.

The problem came and went, however, it would repeat itself eveyr couple of weeks or so. I hadn't called my ISP yet because the problem seemed very sporadical.

However, for about one week now, I can't seem to get my connection to go over 40-50ish KB/s. After hours of argueing with my ISP's technical support, who couldn't find a simple solution over the phone, they have arrived to two possible sources of the problem: It's either the telephone wiring in my house, or there's a problem with the modem itself.

I know my PC is not the problem as I have no spyware / virus / malware.

I also have an Ubuntu Partition with the same problem.

My network card is not the problem either. I can plug the modem via USB to my PC with the same exact problems.

Today a tech from the telephone company came to check the integrity of the wiring. No go. Everything is fine.

I tried different filter and splitters, no go. I tried not using a filter at all. Same results.

Tomorrow the tech will come again to replace the modem (a 5200 speedstream ADSL modem). But I'm skeptical.. specially because sometimes I DO get my old speeds back. Yesterday, for instance. Today it's crap again.

This is driving me nuts...I know very little about DSL and do not know where the source of the problem is...

Does anyone have any suggestions / ideas as to what the problem might be?

Thanks in advance.

 

[Kelemvor]

assuming you tried pulling the plug on the modem and letting it sit for a while... I'd have told them to replace the modem first thing.

 

[Noema]

Originally posted by: FrankyJunior
assuming you tried pulling the plug on the modem and letting it sit for a while... I'd have told them to replace the modem first thing.

Yeah, I've tried that. Didn't work.

They'll bring the new modem tomorrow so we'll see. At any rate I think I should get a router anyway as well, since this is only a modem. My parents have a 2wire Modem / router from the same ISP and it works great. I don't think it has ever cut them off in over a year.

 

[cmetz]

Noema, do some research e.g., on dslreports.com and find out if there is a way to pull the ADSL PHY statistics out of your modem. You're looking for how many tones train (that is, connect speed), noise margin, FEC error stats, and ARQ/retransmission stats. This all will tell you whether the problem is a physical problem with your copper loop or a higher-level problem like with their network.

Also, I have found that when you're dealing with clueless level 1 support types, having a lot of solid hard data in your hands helps you escalate to someone who can actually get you fixed. The same exact data is available in the DSLAM and could easily be made available to tech support folks... but I'm not always convinced that the various ADSL LECs really want to fix all those performance problems...

 

[yukichigai]

Many ISPs like to push their lines to the limit in terms of speed, offering ludicrous speeds to entice customers. In many cases this winds up doing more harm, as the minor line noise that may rarely cause packet loss on a 1.5M connection can literally cripple a 3M connection.

Shocking as it may seem, there is a reason for bandwidth caps other than screwing the customer. Your lines may test fine according to them, but with the number of users connected during day X, etc. it may not be good enough to handle the speed you're rated for. You get higher packet loss, and in the end you wind up going slower than you would if you had a bandwidth cap because you keep having to re-transmit data due to malformed and incomplete packets.

That's just my theory though.

Regardless, this is an ISP problem. Keep bugging them. Ask them to test your house wiring while you're at it; you could have a short somewhere, or maybe a phone/etc. hooked up that isn't grounded properly and is shooting off interference every so often.