SRV, which is an abbreviation for Service, is a DNS record, which permits you to use a domain for a particular service different from a site. By creating a few SRV records, you’re able to use the domain address with different companies and forward it to a number of servers at once, each and every server managing a separate service. You'll be able to 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 two records that are employed for the same service, but direct to different servers for redundancy or load balancing. By having an SRV record you can employ your domain or a subdomain under it for a Voice-Over-IP server, for instance, and have the real software running on a number of machines with different companies. Which one a customer of yours will use depends on the priority and weight values you have set.