SRV, which is an abbreviation for Service, is a DNS record, which allows you to use a domain for a particular service different from an Internet site. By setting up a few SRV records, you can use the domain address with different providers and point it to many servers at a time, each and every server handling a separate service. You'll be able to specify the port number for the connection to each machine, so there won't be any interference. You can even set different priorities and weight for two records which are used for the very same service, but point to different servers for redundancy or load balancing. With an SRV record you can employ your domain or a subdomain under it for a Voice-Over-IP server, for instance, and have the specific software running on several machines with different companies. Which one a customer of yours will use will depend on the priority and weight values you have set.