SRV, which is an abbreviation for Service, is a DNS record, which enables you to use a domain name for a specific service different from a site. By setting up a number of SRV records, you’ll be able to use the domain address with different companies and point it to numerous servers at once, each and every server handling a separate service. You could specify the port number for the connection to every machine, so there won't be any interference. You can even 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. Using 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 actual software running on several machines with different companies. Which one a customer of yours is going to use depends on the priority and weight values that you have set.