On Thu, 4 Oct 2012 04:41:52 -0700 (PDT), wrote:

"No DSL modem comes with more than one ethernet port. "

Your posts indicate intelligence, are logical and all that, but this one time you erred. Claimed a negative. You know better.

Two 2WIRE modems I know (and actually did the setup) have four RJ45s as well as four channel 802.11. (g I think)

Give me a 2wire model number and my guess(tm) is that it will be
a router inside. All (and I do mean all) 2wire devices that have
built in wireless also have a router inside. Marketing may call is a
"modem", but if it has a router inside, it's really a "DSL router".

Of course you could argue that these are routers or whatever, but really fastforwarding through the argument which would be fruitless anyway, how different is it ? Isn't the DSL MODEM just a router or switch that connects to a "slightly" bigger network ?

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.

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.

DSL Router: Contains a DSL modem where the ethernet port is connected
to an internal router. Always includes NAT/PAT to allow a single IP
address to serve multiple non-routeable IP addresses on the LAN. The
modem works on the MAC layer, while the router works on the IP layer.
A 5 port (yes 5 ports, not 4) ethernet switch on the router output
allows connections with additional devices. If an optional internal
wireless access point is included, it connects to the 5th ethernet
port allowing additional connections.

Not the greatest definition, but I think it will suffice.

Two ways of thinking about it but I think neither is wrong.
J

Only two ways? In the distant past, I tried to reconcile the various
names for wireless ethernet bridges and gave up. Too much naming
creativity in an industry that can't even get NAT and PAT correct.
http://wireless.navas.us/index.php?title=Wi-Fi#Wireless_Bridge_Types
With that much creative naming, I don't want to even think about
cleaning up the descriptions of the various wireless access point,
routers, bridges, gateways, switches, media servers, etc.

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558