nanog mailing list archives

Re: Cable Modem [really good network design]


From: Fletcher E Kittredge <fkittred () gwi net>
Date: Tue, 26 Jun 2001 14:52:03 -0400


On Tue, 26 Jun 2001 14:27:29 -0400  "Wojtek Zlobicki" wrote:
The Ethernet protocol was designed to adjudicate and route packets
internal to one homogeneous, physical network.  It handles media
access, security, reliablity and routing in that one physical network.

What does Ethernet have to do with routing ?

Routing in its original sense.  You stick an Ethernet frame in here,
it traverses a number wires connected by boxes which make decisions as
to which wire it should go out on.  It then pops out on the other edge
of the network.  Magic!

A network of Ethernet switches looks a heck of a lot like routers.
They are certainly smarter than the IP routers of circa 1983.

The problem you dont really have one physical network. We are trying
to extend Ethernet into a logical network.

Who is "we" in this statement?

 The
reason that I like PPPoATM is that the end device requires littel
intelligence , it knows one PVC, and all changes (linking them to the
ISP of choice, propogate easily downstream)

Little intelligence to implement ATM?  Never heard that claim before.

Contrast the cost of an Ethernet chip with an ATM chipset.

.RFC 1483 (Ethernet over
ATM, used in DSL and plausibly in cable ) is a great idea for business
but not suitable for home users.  Hardware that you speak of becomes
just too expensive.

Define "great idea".  Compare and contrast with all the failed DSL
providers which used ATM.  Use one DSL/ATM provider who is making money as
an example.  No excuses please.

How do you reconcile the cost of the hardware being too expensive with
the statement above that ATM requires little intelligence?

It appears as if someone has thought of this before   Someone is apparently
doing this already (I don't know the name of the company), taking regular
cable
modems and using wireless for intramodem communication (why re-invent the
wheel)
instead of copper.

That would be a good idea.

regards,
fletcher

 


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