SRV, which is an abbreviation for Service, is a DNS record, which enables you to employ a domain name for a particular service different from a website. By setting up a couple of SRV records, you can use the domain name with different providers and forward it to numerous servers at the same time, each server managing a different service. You are able to specify the port number for the connection to each machine, so there will not be any interference. You can also set individual priorities and weight for two records that are employed for the same service, but forward to different servers for redundancy or load balancing. Using 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 real software running on several machines with different companies. Which one a client of yours is going to use will depend on the priority and weight values which you have set.