Defines whether the circuit is an access link or inter-nodal
link (trunk).
Traffic monitoring, traffic priority determination, traffic
discardability level determination are done at access link and each
incoming packet on an access link is tagged with the information.
Inter-nodal link (trunk) uses the above tagged information in packets
for priority queueing and discarding packets during congestion.
WARNING - It is important to set the appropriate link type for this
attribute otherwise congestion control will not work. The default
value for this attribute is access link. This attribute value
must be changed to CNGC_LINK_INTER_NODAL for inter-nodal link(trunk).