SRV, which is an abbreviation for Service, is a DNS record, which allows you to use a domain for a specific service different from an Internet site. By setting up a few SRV records, you are able to use the domain address with different providers and direct it to several servers simultaneously, each server managing a different service. You'll be 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 different priorities and weight for 2 records that are employed for the exact same service, but point to different servers for redundancy or load balancing. Using an SRV record you can use your domain name or a subdomain under it for a Voice-Over-IP server, for example, and have the real software running on various machines with different providers. Which one a customer of yours is going to use is determined by the priority and weight values that you have set.