SRV, which is an abbreviation for Service, is a DNS record, which enables you to employ a domain for a certain service different from a site. By setting up a number of SRV records, you can use the domain with different companies and forward it to numerous servers simultaneously, each and every server managing a different service. You'll be able to specify the port number for the connection to every machine, so there won't be any interference. You can even set individual priorities and weight for two records which are employed for the exact same service, but direct to different servers for redundancy or load balancing. With an SRV record you can use your domain name or a subdomain under it for a Voice-Over-IP server, for instance, and have the actual software running on several machines with different providers. Which one a customer of yours will use will depend on the priority and weight values you have set.