SRV, which is an abbreviation for Service, is a DNS record, which enables you to employ a domain for a particular service different from an Internet site. By creating a number of SRV records, you will be able to use the domain name with different companies and point it to a number of servers simultaneously, each server handling a separate service. You can specify the port number for the connection to each and every machine, so there will not be any interference. You could also set individual priorities and weight for 2 records that are employed for the same service, but forward 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 companies. Which one a client of yours will use depends on the priority and weight values which you have set.