SRV, which is an abbreviation for Service, is a DNS record, which permits you to employ a domain name for a specific service different from a website. By creating a number of SRV records, you’ll be able to use the domain name with different companies and forward it to many 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 won't be any interference. You may as well set different priorities and weight for 2 records which are used for the same service, but forward to different servers for redundancy or load balancing. Using an SRV record you can employ your domain name or a subdomain under it for a Voice-Over-IP server, for example, and have the specific software running on a number of machines with different providers. Which one a client of yours will use will depend on the priority and weight values that you have set.