Sign-In

The sign-in process is a very involved process, especially with the new LyncDiscover and Mobility Services. The following list provides each step of the LyncDiscover process. Figure 24.3 provides an overview of the LyncDiscover process.

Figure 24.3. LyncDiscover process.

1. The client first queries the DNS records for LyncDiscoverinternal and then LyncDiscover.

2. The client connects to the appropriate URL, including the SIP URI of the user as part of the URL.

3. The LyncDiscover service responds with the full LyncDiscover service URL and web ticket service URL for users to request server information.

4. The LyncDiscover service requires the client to authenticate and receive a valid web ticket. The client performs authentication with the web ticket service before attempting to interact with the LyncDiscover service again.

5. When the client has a valid web ticket, it sends a full request to the LyncDiscover service. If the message is valid, the LyncDiscover service returns connectivity information for that client and user.

At this stage, a client will have authenticated with the web ticket service, essentially authenticating with Active Directory. Also, the client will have received the Mobility Service URL and the FQDN for a Front End Server and associated Edge Server for SIP connectivity. Next, the mobile client must register against the Mobility Service URL. Figure 24.4 outlines the registration process for a Lync 2010 mobile client to the MCX service.

Figure 24.4. Lync 2010 Mobile Client Registration Process.

The following list outlines the Lync 2010 Mobile Client registration process:

1. The mobile client initiates a registration request to the MCX service. The MCX service requests a valid web ticket.

2. The mobile client sends another registration request with the web ticket authentication. At this stage a session is created on the Front End Server for this mobile device and user. A unique ID is created to specifically identify the endpoint.

3. The client begins receiving in-band settings from the server. This includes services such as the address book service, group expansion, and policy settings that apply to the mobile endpoint.

4. The client starts to process the contact list for that user. This includes downloading the contact list objects, subscribing to presence, and downloading photos. These requests are all similar to the Lync desktop client; however, the requests are made in XML messages over HTTPS to the MCX service.

At this stage the Lync mobile client will act much like any other Lync client. The key difference is the format in which messages are delivered to clients.