SRV, which is an abbreviation for Service, is a DNS record, which enables you to use a domain name for a particular service different from an Internet site. By setting up a number of SRV records, you are able to use the domain address with different companies and forward it to many servers simultaneously, each server handling a separate service. You could specify the port number for the connection to each and every machine, so there will not be any interference. You may as well set individual priorities and weight for 2 records which are used for the same service, but forward to different servers for redundancy or load balancing. Using an SRV record you can employ your domain name or a subdomain under it for a Voice-Over-IP server, for example, and have the specific software running on various machines with different providers. Which one a customer of yours will use depends on the priority and weight values that you've set.