The MPLS WG Archive

[David Charlap <david.charlap@marconi.com>]

Steve Nash wrote:
> 
> The VPI and VCI are assigned by the administrator through his/her
> configuration on the particular ATM switch(es) they are configuring.
> That then is handed off to the customer as the PVC (vpi/vci).  The
> ATM switch usually has an IP address so you can manage it (oob,
> side-band, whatnot management).  When a new ATM switch is added to
> the network, it is usually meshed into the existing ATM
> infrastructure, and if it is added between switches, you have to
> make sure it contains all the PVC information for all your
> customers/internal PVCs...etc

This is massively off topic for this list.  ATM information is available
from the ATM Forum: http://www.atmforum.com/.

As for your particular description, that is but one method.  ATM
switches have not required manual configuration of PVCs for quite a long
time, even though many sites still prefer it over the automatic VC setup
mechanisms.

ATM switches have per-port NSAP addresses.  They are not IP addresses.

ATM switches run routing protocols (like PNNI), which are used to
compute paths through the network.

There are signaling protocols (like UNI) which are used to set up
virtual circuits without manual specifying the VPI/VCI at every hop.

There are a great many other protocols in ATM that do other useful
things, but this is not the place to get into a discussion of them. 
Specifications are available from the ATM Forum's web site.  There are
also many books on the subject.

-- David