3Com CoreBuilder 7000 Operation Manual page 39

of addressing information between the user and the network at the UNI,
at initialization and at other times, as required.
Address registration is done in two phases. The network side IME supplies
the network prefix of the address, and the user side IME appends the user
part to it and registers the complete address with the network side. Either
side can dynamically register and de-register its respective parts of the
address. This registration process provides the network with the
information needed to automatically route a call to its destination
address.
The user-side device automatically registers its organizational scope
variable with the network side in order to assure that the network is
aware of the users attached to it (see next section).
Organizational Scope for Group Address
The CoreBuilder 7000 family switch ILMI supports the organizational
scope for a registered ATM group address. The organizational scope
restricts the distribution of information related to the group address
within the network. This variable supports the group address of an ATM
device and the Anycast facility. Anycast is the ability to allow an
application to request a P2P connection over a single ATM end system
that is part of an ATM group.
ATM Address Format
An ATM end station address uniquely identifies an ATM endpoint. The
format of an ATM address is modeled after the OSI Network Service
Access Point (NSAP), using the same structure, abstract semantics, syntax,
and preferred binary encoding.
Three different formats are specified:


Data Country Code (DCC) ATM format — ISO. The Data Country
Code specifies the country in which an address is registered. The
length of this field is two octets. The digits of the data country code
are encoded in Binary Coded Decimal (BCD) syntax. The codes will be
left justified and padded on the right with the hexadecimal value "F"
to fill the two octets. Use this format for organizations that want to
maintain a private numbering plan that is organizationally based for
countries.


International Code Designator (ICD) ATM format — ISO. This identifies
an international organization. The registration authority for the
Basic ILMI Functions 39