SRV, which is an abbreviation for Service, is a DNS record, which permits you to employ a domain for a certain service different from a website. By setting up a number of SRV records, you can use the domain with different providers and point it to several servers simultaneously, each and every server managing a separate service. You are able to specify the port number for the connection to every single machine, so there won't be any interference. You may as well set individual priorities and weight for two records which are used for the exact same service, but point 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 instance, and have the specific software running on various machines with different companies. Which one a customer of yours will use depends on the priority and weight values you have set.