This attribute specifies a unique string, set by the operator, which
identifies the call for accounting purposes. Downstream processing
uses this attribute to correlate accounting records issued at different
nodes in the network. Normally, this value is provisioned with the
same value at each end of the connection. If the value of
accountingEnabled is no, this attribute has no effect. This attribute
is also visible in the FrAtm Dlci component when accounting is
enabled.