SRV, which is an abbreviation for Service, is a DNS record, which permits you to employ a domain for a certain service different from an Internet site. By creating a couple of SRV records, you are able to use the domain address with different companies and forward it to numerous servers at once, each and every server handling a separate service. You can specify the port number for the connection to each and every machine, so there will never be any interference. You can also set different priorities and weight for two records that are employed for the same service, but forward to different servers for redundancy or load balancing. By having an SRV record you can use your domain name or a subdomain under it for a Voice-Over-IP server, for example, and have the real software running on several machines with different providers. Which one a client of yours will use is determined by the priority and weight values that you've set.