SRV, which is an abbreviation for Service, is a DNS record, which permits you to employ a domain for a specific service different from a website. By creating a couple of SRV records, you’ll be able to use the domain with different providers and direct it to a number of servers at the same time, every single server handling a separate service. You can specify the port number for the connection to every single machine, so there will never be any interference. You can even set individual priorities and weight for 2 records which are used for the same service, but direct to different servers for redundancy or load balancing. Using an SRV record you can use your domain address or a subdomain under it for a Voice-Over-IP server, for example, and have the actual software running on a number of machines with different companies. Which one a client of yours will use depends on the priority and weight values you have set.