SRV, which is an abbreviation for Service, is a DNS record, which allows you to use a domain for a particular service different from a website. By setting up a number of SRV records, you will be able to use the domain with different companies and direct it to several servers simultaneously, each and every server managing a different service. You could specify the port number for the connection to every single machine, so there won't be any interference. You can also set individual priorities and weight for two records that are employed for the very same service, but point 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 instance, and have the actual software running on various machines with different companies. Which one a customer of yours will use is determined by the priority and weight values that you have set.