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 creating a number of SRV records, you will be able to use the domain with different providers and direct it to numerous servers at once, each server handling a different service. You are able to specify the port number for the connection to every single machine, so there won't be any interference. You may as well set individual priorities and weight for 2 records that are used 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 example, and have the real software running on a number of machines with different companies. Which one a customer of yours will use is determined by the priority and weight values which you have set.