If you are adding an SRV because you are setting up Office365 and alike, then this article is for you.
What is an SRV?
A Service record (SRV record) is a specification for adding information to a domain about a service. Typically, it shows a location, port number, priority and weight of servers for specified services.
You will mostly likely be asked to add an SRV record, when you sign up for a service to the domain, such as a hosted exchange or VoIP service.
Here is what a typical SRV record looks:
_sipfederationtls._tcp 5061 1 100 sipfed.online.lync.com 3600
_sip – Service
_tcp – Protocol
5061 – Port
1 – Priority
100 – Weight
sipfed.online.lync.com – Target
3600 – TTL
To apply an SRV to your domain, you would log into your hosting and add it using the "Advanced DNS Zone editor"
The confusion comes when you try to apply the SRV to cPanel hosting. When adding it, you'll notice there is no box for the protocol (see above).
To fix this, you need to add ._protocol to the end of the name. In the example above, it goes from _sipfederationtls to _sipfederationtls._tcp
Once the SRV record is added, it will generally be available from our DNS servers within 30 minutes. However, due to the nature of DNS being cached, other systems may not "see" the record for 8-24 hours.