Directory types are:
1 - Home
The LU is in the domain of the local network node
and the LU information has been configured at the
local node.
2 - Cache
The LU has previously been located by a broadcast
search and the location information has been saved.
3 - Register
The LU is at an end node that is in the domain
of the local network node. Registered entries
are registered by the served end node.