| Description | The VCCI, or Virtual Circuit Connection
Identifier, is a variable that identifies a
virtual circuit connection between two nodes.
A virtual circuit connection, or VCC, consists of
one virtual circuit link or a series of concatenated
virtual circuit links. In its most common usage,
the value of the VCCI is unique between the nodes
at the extremities of the virtual circuit
connection, but not on a network-wide basis. Hence,
its value needs to be qualified by the ATM
addresses of these end nodes. At one of these
end nodes, its value needs to be qualified by the
ATM address of the far-end node. Some applications
can extend this definition to make the VCCI value
unique on a network-wide basis. This is specially
possible when VCCIs are administered from a management
system and not locally assigned by a node.
In this MIB, the VCCI serves as a label to be assigned
by an external application. VCCIs need to be unique
for a given remote peer, however, the same VCCI can
be reused for different remote peers. Accordingly,
the combination of (remote address, VCCI) will always
be unique for any given agent. This allows a controller
to refer to a VC by the VCCI and remote peer address,
in contrast to VPI/VCI and port. It thus constitutes
a convenience feature, providing an alternative
identification scheme for a VC which is managed by
an outside user, such as a management system.
The remote peer address can be specified in NSAP,
E.164, or GWID format, as indicated by the address
type (vismRemoteAddressType). Depending on the
address type specified, uniqueness will be relative
to NSAP, E.164 address, or GWID.
It is recommended not to change the value of this
object once it has been created. However,
upon modification, it will be ensured that the
resulting combination of VCCI and remote address
is unique. Requests that would result in a
non-unique combination will be rejected.
Beyond this, there are no other integrity constraints
that will be enforced for this object. This includes
network-level consistency whether the remote peer,
or an external controller, use the same VCCI
designation for the VC. |