Cell Relay Archive

[Paul Koning <pkoning@lucent.com>]

bdonalds wrote:
> 
> I am a bit confused as to the way ATM switches handle or
> see traffic in a LANE environment.  My understanding (in my
> particular architecture) is that as frame traffic reached
> the ingress switch, a SAR is performed, and the traffic
> proceeds into the cloud as cell traffic, which then gets
> SARed again at the egress switch, and proceeds to the end
> device as frame.  (assuming both nodes are on the same
> ELAN)  My question is, what then are the configuration
> settings on pure ATM switches regarding frame size/buffer,
> MTU etc reflecting?  Wouldn't everything in the ATM cloud
> be a 53 byte cell?  What concept am I not grasping?

It sounds like there's a mixup of switches.

The LANE end system is where the SAR function is done.
ATM switches are not involved in that; they just switch
cells.

A LANE end system can be several things: it can be a
host with an ATM NIC.  It can also be a router, or it
can be a LAN Bridge (802 style bridge).  That last kind
of device is often called a "switch" by marketeers who
think that "switch" sounds fast and "bridge" sounds slow.
That never was true and never made sense but it's 
ingrained by now.

So what probably happened is that someone was talking
about a "switch" in the sense of a LAN bridge, and
you misinterpreted that as a reference to an ATM switch.

	paul

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