SRV, which is an abbreviation for Service, is a DNS record, which enables you to employ a domain name for a specific service different from a website. By setting up a few SRV records, you will be able to use the domain with different providers and direct it to a number of servers at a time, each and every server handling a separate service. You can specify the port number for the connection to every machine, so there will never be any interference. You can also set individual priorities and weight for two records which are employed for the very same service, but direct to different servers for redundancy or load balancing. By having 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 various machines with different companies. Which one a customer of yours is going to use is determined by the priority and weight values you have set.