<div class="content"><p>This protocol enables clients to retrieve the network name
of a server from a <span><a href="8a0b2177-60de-4dca-b815-9d83663dfff4#gt_e63aea5b-046b-4176-9359-fde82613a406" data-linktype="relative-path">name service provider interface
(NSPI)</a></span> referral server. Clients use this protocol before performing
any NSPI requests, in order to retrieve the name of the NSPI server to connect
to. This gives the NSPI referral server the ability to control which NSPI
server an NSPI client will connect to, for purposes including but not limited
to balancing the client load across multiple NSPI servers, choosing the best
version of NSPI server for that particular client, or satisfying network
requirements that are not discernible by the client. Clients also use this
protocol to retrieve the <span><a href="8a0b2177-60de-4dca-b815-9d83663dfff4#gt_1769aec9-237e-44ed-9014-1abb3ec6de6e" data-linktype="relative-path">FQDN</a></span> of the <span><a href="8a0b2177-60de-4dca-b815-9d83663dfff4#gt_d3ad0e15-adc9-4174-bacf-d929b57278b3" data-linktype="relative-path">mailbox</a></span>
server, when only the <span><a href="8a0b2177-60de-4dca-b815-9d83663dfff4#gt_1175dd11-9368-41d5-98ed-d585f268ad4b" data-linktype="relative-path">DN</a></span> the mailbox
server is known. Figure 1 shows the request to the NSPI referral server for the
name of the NSPI server and the server’s response to the client. Figure 2 shows
the request to the NSPI referral server for the FQDN of the mailbox server and
the server’s response to the client.</p><p><img id="MS-OXABREF_pictf49db77c-2490-49eb-96be-4e7f5b764f0e.png" src="ms-oxabref_files/image001.png" alt="Client retrieving NSPI server name from the NSPI referral server" title="Client retrieving NSPI server name from the NSPI referral server" data-linktype="relative-path"/></p><p><b>Figure 1 Client retrieving NSPI server name from the NSPI
referral server</b></p><p><img id="MS-OXABREF_pict8346fb18-3d4d-42ec-b03f-466c208ea72d.png" src="ms-oxabref_files/image002.png" alt="Client retrieving mailbox server name from the NSPI referral server" title="Client retrieving mailbox server name from the NSPI referral server" data-linktype="relative-path"/></p><p><b>Figure 2 Client retrieving mailbox server name from the
NSPI referral server</b></p></div>