My DSL has 50ms more latency than others on the same ISP?

matts5074

Hey guys. I've been looking at this for the past couple days and I cannot figure anything out. My first hop is 60ms away, where everyone else in town seems to be 10-15ms away despite the fact that I live 3 times closer to the telco than they do! We both take the exact same path out to the internet.

I've tried the obvious.... reformat, different NIC, different cable, different phone cord to the walljack, and power cycling the modem.

I can post traceroutes if you guys want..... but the extra latency is between myself and the local telco. I've tried tracing both out and in from a remote server both show latency to be in the same place.

halflife78

Do you have Directv with the phone line hooked up to one of the receivers by chance? I had this same issue and the Directv phone line was causing it. Sorry, it's late here at work, out dataroom flooded and that's the only idea I can think of atm.

matts5074

No satellite at all. But thanks for trying.

The only thing I can think of is I'm farther away from the exchange, but I'm still closer to 2 miles than 3 miles. Anyone ever heard of using ferrite cores to clean up a signal?

The only thing I haven't tried is plugging the DSL modem straight into the box outside, although I doubt that will help.

Sartan

At the risk of not getting too technical..
It could very well be just the physical phone lines.
Attenuation, Cross talk, etc etc etc.

Are your POTS splitters all new?

It's likely a physical issue.
Run a packet sniffer (Ethereal is a favorite choice) and carefully watch the ACK/SYN statements and check to see if they are sequential for the most part. If it looks like you have to retransmit quite often, then you can narrow it down to layer 4, and think of new drivers.

And in conclusion, it's a physical issue, most likely outside of your house (the local loop).

You can even narrow that down further by disconnecting all of the other lines in your house at the demarcation point (Point in which the telco puts a line in your house). It might just be old wire. Wire sags, stretches, etc.

60ms is quite a bit, though. Outside of your house, is there a transformer, cellular tower, etc near your line? Is your phone line travelling near your furnace or hot water heater?

matts5074

When I first made this post I had 2 lines, one for DSL and one for normal telephone use. This being a waste of money I cancled the other line and had it all moved to the other one (older). Didn't make a difference at all in ping times. The line I had it on at the time of this post was fairly new, they installed it 2 years ago or so off the pole in the back yard.

I haven't tried or thought of the packet sniffer, I'll give that a shot tonight. There is a transformer about 300 feet from the telephone pole and the telephone lines do indeed use the same pole, but they are about 3ft below the power lines (best I can tell). There is a cellular tower in sight, but I'd say it's a good 2 miles away up on the mountain. The lines travel up the back of the house under the carport, down the wall, and come straight through the wall into the jack. So no, they don't pass anything electrical coming into the house.

Thanks for your reply. If nothing else, I learned something.