Accessing a Dsl system using telephone number information?

[Hollis40]

Can someone can tell if a PC system on dsl has logged onto the internet by knowing the telephone number of the user's line? For example I may have friends with whom I associate on the net and we share our email and sometimes our telephone numbers and wind up talking over the phone after we get to like and trust each other. And this is all assuming they don't have my mac address or any IP ranges assigned to me or anything like that, just the telephone number. If one of them decides to snoop around could they use that number with basic networking to at least tell if I'm logged onto the net? And then can they intrude further to find my mac address and more?

 

[jpmkm]

Isn't your dsl always on? I didn't think you had to log on every time you used it. Short answer, though, is no, they cannot determine that information from just a phone number(unless they somehow had access to the telco's system). I'm not sure what it matters, though. You are probably more likely to be randomly targetted by some fool you don't know than a friend you met on the internet. MAC addresses don't get passed beyond the first hop, so that wouldn't do them much good anyway.

 

[Hollis40]

Thanks for the reply on the mac # and other issues. About the dsl being on always, I think it is. But I plan to pull out the cable to the dsl modem whenever I'm off the net. I figure that will help against random hacks. I hope that doesn't mess up my dsl in any way. It should be ok to disconnect and connect the incoming connector jack.

 

[BollWeevil]

With DSL, the phone line entering the telco's office (or remote station) gets physically split into two signals throug the use of band-pass filters. The low frequency output (below 4000 Hz), which carries voice is sent to the telco's switch system. High frequency output, which carries data, is sent to the DSL provider. Many times the DSL provider is a different company than the phone provider, (unless your DSL provider is a CLEC like SBC), so it's conceivable that your telco doesn't even see the DSL signal at their terminating equipment.

Basically, the phone line is being used for two separate signals. The only reason your DSL is tied to your phone number is so the provider can figure out which account to bill and which wire to plug in to the DSL system.

 

[xXaNaXx]

Thanks for the reply on the mac # and other issues. About the dsl being on always, I think it is. But I plan to pull out the cable to the dsl modem whenever I'm off the net. I figure that will help against random hacks. I hope that doesn't mess up my dsl in any way. It should be ok to disconnect and connect the incoming connector jack.

i wouldn't unplug the phone line from the DSL modem when not in use, personally.....i'd rather just get a Linksys/Netgear/D-Link/etc. router for a hardware firewall, and also run a software firewall on the computer itself. there is still a remote chance that someone could get in, but it's so remote that i wouldn't even consider it a possibility.

the majority of intrusions are done by someone that's pissed off at a company (like the whole "Linux community vs. SCO Unix" fiasco a while back) and is wanting revenge, or someone leaves their cable modem/DSL connection wide open with no firewall protection, or the person whose system has been intruded upon was compromised due to them getting a virus/trojan.

and even if they did get in, so what? if you make regular backups of stuff that you consider important (which should be common practice, but unfortunately, is not), and don't keep a bunch of financial or other such sensitive information on your computer, then there's not much reason to worry.