This article describes the fix for the Skype for Business/Lync Attendee error that external contacts receive when they try to connect.
- Skype for Business/Lync 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 because 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)
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 for SRV record:
- Service: _sip
- Protocol: _tls
- Port number: 5061
- Host: lyncsip.exch0XX.serverdata.net or skypesip.exchXXX.serverdata.net or sip.exchXXX.serverdata.net
Important: to protect your account information, we cannot publish your Server names in the public Knowledge Base. The correct settings can be found under CONTROL PANEL > Services > Domain Name > Click on your domain name > Display DNS records > Show System Records. Read the Knowledge Base article on How To Add SRV Record To Your Domain for more information about SRV record syntax.
- 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 188.8.131.52
nslookup - someDNSserverIP
- The results should look like this:
priority = 0
weight = 0
port = 5061
srv hostname = lyncsip.XX.XX.XX