5.3 Computational Viewpoint
The computational viewpoint specifies the
resource provisioning interface for the delete-
TopologicalLinkaction as follows:
<COMMUNITY: IP topology management,
ACTION: delete topological link>
OPERATION deleteTopologicalLink {
INPUT_PARAMETERS
layerND: LayerNetworkDomainId;
topologicalLink: TopologicalLinkId;
OUTPUT_PARAMETERS
-- none
RAISED_EXCEPTIONS
incorrectTopologicalLink:
TopologicalLink;
serverTrailExisting: NULL;
failureToDeleteTopologicalLink: NULL;
BEHAVIOUR
SEMI_FORMAL
PARAMETER_MATCHING
layerND:
<INFORMATION OBJECT:
iptomLayerNetworkDomain>;
topologicalLink:
<INFORMATION OBJECT:
iptomTopologicalLink>;
PRE_CONDITIONS;
inv_existingTopologicalLink
“topologicalLinkrefers to the element
in the <layerNetworkDomainIsMadeOf>
relationship where layerNDrefers to
containerLND.”
inv_noServerTrail
“topologicalLinkshall not refer to
anyclientTLof a <topologicalLinkIs
SupportedByTrail> relationship.”
POST_CONDITIONS
inv_noTopologicalLink
“topologicalLinkdoes not participate in
any <layerNetworkDomainIsMadeOf>
AND <iptomLinkBinds> relationships.”
EXCEPTIONS
IF PRE_CONDITION inv_existing-
TopologicalLink NOT_VERIFIED
RAISE_EXCEPTION incorrect-
TopologicalLink;
IF PRE_CONDITION inv_noServer-
Trail NOT_VERIFIED
RAISE_EXCEPTION server-
TrailExisting;
IF POST_CONDITION inv_no
TopologicalLink NOT_VERIFIED
RAISE_EXCEPTION failure-
ToDeleteTopologicalLink;
;}
INPUT_PARAMETERS specifies the input
parameters to this action. The topologicalLink
parameter identifies the topological link that is
to be deleted. The layerND parameter is implic-
itly provided, as it is the containing entity of the
topological link (see Figure 12).
OUTPUT_PARAMETERS specifies the output
parameters from this action, which is normally
none.
RAISED_EXCEPTIONS specifies return values
in case the action fails.
PRE_CONDITIONS specifies the conditions
that have to be present prior to the action re-
quest. The invariant inv_existingTopological-
Link refers to the fact that the topological link
has to exist. The invariant inv_noServerTrail
refers to the requirement that the topological
link to be deleted shall not be associated with
a server trail.
POST_CONDITIONS specifies the conditions
that are present when the action is completed.
The invariant inv_noTopologicalLink refers to
the fact that the deleted topological link does not
exist after the deleteTopologicalLinkhas suc-
cessfully completed.
Figure 12 Relationship
diagram for topological link
and related entities
iptomLayerNetwork
Domain
iptomTopologicalLink
iptomLndCan
ServeLnds
layerNetworkDomain
IsMadeOf
1..1 +containerLND
+client
1..*
0..* +element
iptomServerTrail
iptomServerLayer
NetworkDomain
topologicalLinkIs
SupportedByTrail
1..* +clientTL
1..1 +serverTrail
layerNetworkDomain
IsMadeOf
0..* +containerLND
1..1 +containerLND
+server
1..1