SRV, which is an abbreviation for Service, is a DNS record, which permits you to employ a domain for a specific service different from an Internet site. By creating a number of SRV records, you are able to use the domain name with different providers and forward it to several servers simultaneously, every single 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 different priorities and weight for 2 records that are used for the very same service, but forward to different servers for redundancy or load balancing. By having an SRV record you can use your domain address or a subdomain under it for a Voice-Over-IP server, for instance, and have the real software running on various machines with different companies. Which one a customer of yours will use is determined by the priority and weight values that you have set.