SRV, which is an abbreviation for Service, is a DNS record, which permits you to employ a domain name for a specific service different from a website. By setting up a number of SRV records, you’ll be able to use the domain address with different companies and direct it to many servers simultaneously, each and every server handling a separate service. You could specify the port number for the connection to each machine, so there will not be any interference. You may as well set individual priorities and weight for two records which are used for the exact same service, but forward to different servers for redundancy or load balancing. By having an SRV record you can use your domain or a subdomain under it for a Voice-Over-IP server, for example, and have the actual software running on various machines with different providers. Which one a client of yours is going to use will depend on the priority and weight values you have set.