Hi all,

I reviewed the automatic login process in Lync 2013,and  I found that the first steps are different than Lync 2010.

In Lync 2010 the login process was the follow:

• _sipinternaltls._tcp.<sip domain>
• _sip._tls.<sip domain>
• sipinternal.<sip domain>
• sip.<sip domain>
• sipexternal.<sip domain>

I put a Wireshark trace on my Lab with Lync 2013

Note: I did not create any DNS register, because I wanted trace the full process.

 

1) DNS A Register : lyncdiscoverinternal.<sip domain>

This DNS A Register was included since Lync 2010 CU4 to offer Lync Mobile Service. Now with Lync 2013, it’s the first option to automatic login.

 

2) DNS A Register: lyncdiscover.<sip domain>

As previous register, added to Lync since Lync 2010 CU4, but with different porpouse. This DNS register, allow user outside corporative LAN, to connect to Lync Mobile Clients, the previous one only works for internal users.

3) DNS SRV: _sipinternaltls._tcp.<sip domain>

From here, are same steps as Lync 2010

4) DNS SRV: _sip._tls.<sip domain>

5) DNS A: sipinternal.<sip domain>

6) DNS A: sip.<sip domain>

7) DNS A: sipexternal.<sip domain>

Note: Lync Windows Store, stops in the second step

I hope this help you

Espero les sea de ayuda