This article describes the fix for the Skype for Business/Lync Attendee error that external contacts receive when they try to connect.
The scenario of the issue:
- Skype for Business user initiates a meeting and invites an external contact.
- External contact tries to connect via Skype for Business/Lync Attendee, but receives the following error:
Cannot sign in becasue the server is temporarily unavailable. Reference error ID 28 (source ID 238)
Cannot sign in the Skype for Business/Lync Attendee because of a problem connecting to the server. Reference error ID 102 (source ID 238)
To fix the connection:
- Create a SRV record for your domain. For instance, if firstname.lastname@example.org invites email@example.com the SRV record should be created for yourdomain.com.
You may need to contact your DNS provider to add this record.
Syntax of SRV record:
- Service: _sip
- Protocol: _tls
- Port number: 5061
- Host: lyncsip.XX.XX.XX. For instance, lyncsip.exch0XX.serverdata.net.
You can find the correct setting in CONTROL PANEL > Services > Skype for Business > Instructions.
- Priority and weight can be left 0.
To verify the record is created successfully and propagated:
- Navigate to Start, find Cmd and open it.
- Type the following lines one by one and hit ENTER after each:
Note: If you do not know someDNSserverIP you may use 18.104.22.168
nslookup - someDNSserverIP
- The results should look like this:
priority = 0
weight = 0
port = 5061
srv hostname = lyncsip.XX.XX.XX