SRV, which is an abbreviation for Service, is a DNS record, which enables you to employ a domain for a specific service different from an Internet site. By setting up a few SRV records, you are able to use the domain name with different companies and direct it to a number of servers at once, each server handling a different service. You could specify the port number for the connection to every single machine, so there won't be any interference. You may as well set different 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 name or a subdomain under it for a Voice-Over-IP server, for example, and have the real software running on a number of machines with different providers. Which one a client of yours will use will depend on the priority and weight values which you have set.