SRV, which is an abbreviation for Service, is a DNS record, which enables you to employ a domain name for a certain service different from a site. By creating a few SRV records, you’ll be able to use the domain address with different providers and point it to several servers simultaneously, each server handling a separate service. You could specify the port number for the connection to every single machine, so there will never be any interference. You could also set different priorities and weight for two records that are used for the exact same service, but forward 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 instance, and have the actual 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.