This attribute indicates the direction of the call setup request for an
SVC.
A value of fromLink means that the call setup originated from the
link.
A value of toLink means that the call setup was directed to the link.
For PVC connections, the value of this attribute is notApplicable.
For SPVC connections, the value of this attribute is notApplicable
for Vccs with the SourcePVC and DestinationPVC subcomponents.
For Signalling channels, the value of this attribute is notApplicable.