SRV, which is an abbreviation for Service, is a DNS record, which enables you to employ a domain for a certain service different from an Internet site. 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 at the same time, each and every server managing a different service. You could specify the port number for the connection to each machine, so there will not be any interference. You can even set individual priorities and weight for 2 records which are used for the same service, but point to different servers for redundancy or load balancing. With 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 real software running on various machines with different companies. Which one a customer of yours is going to use is determined by the priority and weight values that you've set.