SRV, which is an abbreviation for Service, is a DNS record, which enables you to employ a domain for a particular service different from a website. By creating a number of SRV records, you are able to use the domain name with different companies and forward it to numerous servers at once, each server managing a different service. You could specify the port number for the connection to each machine, so there will not be any interference. You may as well set individual priorities and weight for two records that are employed for the very same service, but forward to different servers for redundancy or load balancing. By having an SRV record you can use your domain or a subdomain under it for a Voice-Over-IP server, for example, and have the actual software running on a number of machines with different companies. Which one a customer of yours is going to use is determined by the priority and weight values which you have set.