SRV, which is an abbreviation for Service, is a DNS record, which enables you to employ a domain for a particular service different from a website. By setting up a number of SRV records, you can use the domain address with different providers and point it to numerous servers at a time, every single server managing a different service. You'll be able to specify the port number for the connection to each and every machine, so there will never be any interference. You can also set different priorities and weight for two records that are used for the 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 a number of machines with different providers. Which one a client of yours will use depends on the priority and weight values which you have set.