23 Jan 2006 at 01:44 - 11
We are not taking about wireless networking, we are talking about a link to your local gateway, or isp.
What the support agent means, is that, by his friend adding the mac address to his friends account the modem is indeed active anywhere on his friends carrier's network. This also keeps the cost of his/her parents bill. You are not identified by package or home address, An Isp requires the MAC on your device in order to identify who you are and authenticate your access rights on thier network. This is specifically the case with Perdominently (mispelled) cable internet services. Dsl System use pppoe or pppt typically to authenticate by a user account and password hash.
As an example, I have a cable modem I own, and the MAC is linked to my account, I can unplug my modem and go anywhere I want on my carriers network.(<- that being the key) Now that said, some compaines will charge you roaming fees, so be careful, mine dosn't, that dosn't mean yours won't.