You should normally supply 0 for addr.len . This causes the provider to use internal defaults for the starting point of the search. For a protocol family such as AppleTalk, in which every node has access to name and address information, this parameter is meaningless. Consult the documentation supplied with your protocol to determine whether you can or should specify an address. A long specifying the number of names you expect to be returned.
Some protocols allow the use of wildcard characters in specifying a name.
As a result, the OTLookupName function mighg a name. As a result, the OTLookupName function might find multiple names matching the specified name pattern. If you expect a specific number of replies for a particular name or do not expect to exceed a specific number, you should specify this number to obtain faster execution. A long specifying the amount of time, in milliseconds, that should elapse before Open Transport gives up searching for a name. Specify 0 to leave the timeout value up to the underlying naming system.