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’re able to use the domain address with different companies and forward it to several servers at the same time, each server handling a separate service. You are able to specify the port number for the connection to every machine, so there won't be any interference. You may as well set different priorities and weight for 2 records that are used for the exact same service, but point to different servers for redundancy or load balancing. Using an SRV record you can use your domain or a subdomain under it for a Voice-Over-IP server, for example, and have the real software running on several 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.