On Thu, 04 Oct 2012 09:20:07 -0700, Jeff Liebermann
wrote:


Not bigger network, but different network. The definition of a router
is a device that connects two DIFFERENT networks at the IP layer (ISO
layer 3). One port is connected to the greater internet network. The
other port is connected to a local area network, that uses
non-routeable IP addresses.

I mostly agree with your distinction on the difference between modem and
router.

My definitions, which might be different than yours:

DSL Modem: DSL (actually ATM) to ethernet bridge. Everything done at
the MAC layer (ISO Layer 2) with no involvement with IP layer (ISO
layer 3) except for configuration management.

I do not think that what is appearing at the DSL end user terminals is ATM
but closer to VT45 or VT135 with highly compressed data. Moreover you are
looking at data likely being a shared service with a much more broadband
(TV) type service on the same pair.

?-)