SRV, which is an abbreviation for Service, is a DNS record, which permits you to use a domain name for a specific service different from a site. By creating a number of SRV records, you’re able to use the domain address with different providers and forward it to a number of servers at once, every single server managing a different service. You could specify the port number for the connection to each and every machine, so there will never be any interference. You may as well set individual priorities and weight for two records that are employed for the exact same service, but direct to different servers for redundancy or load balancing. With an SRV record you can use your domain or a subdomain under it for a Voice-Over-IP server, for example, and have the real software running on a number of machines with different providers. Which one a client of yours is going to use depends on the priority and weight values that you've set.