When the Pipelock is engaged is effectively cuts off all communication from your modem to the computer with the exception of DHCP updates (releasing/renewing of your IP). I have an Ericsson at home myself and find this feature much easier that powering off my computer or modem when I am not physically present.
"PipeLock® Security Feature Aastra's PipeRider cable modem offers an extra layer of security with its PipeLock® technology. With one touch of a button, communication between your computer and the Internet is suspended. This provides total security for your computer when it's not in use. A second press of the button automatically restores your Internet connection."
Just remember to check this feature before you call in to complain about non-connectivity....trust me, it happens every day!