This attribute specifies whether loop prevention is in effect on this
interface.
When the value is enabled, incoming calls on this interface cannot
be routed back out the same interface. When the value is disabled,
routing of incoming calls back out the same interface is permitted.
The recommended value is enabled. The value disabled should
only be used if routing of incoming calls back out over this interface
is actually required. As an example, the value disabled might be
needed if the interface is connected to an end-user multiplexing
device which has no routing capability.
Note that setting the value to enabled prevents only routing loops
which involve two network nodes.