SRV, which is an abbreviation for Service, is a DNS record, which permits you to use a domain for a specific service different from a website. By creating a few SRV records, you will be able to use the domain with different providers and direct it to numerous servers at once, each server handling a separate service. You are able to specify the port number for the connection to every machine, so there will never be any interference. You could also set different priorities and weight for 2 records which 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 name or a subdomain under it for a Voice-Over-IP server, for instance, and have the specific software running on a number of machines with different companies. Which one a client of yours is going to use will depend on the priority and weight values you have set.