SRV, which is an abbreviation for Service, is a DNS record, which allows you to employ a domain name for a certain service different from a website. By creating a couple of SRV records, you’re able to use the domain address with different providers and forward it to several servers at once, every single server managing a separate service. You are able to specify the port number for the connection to every single machine, so there won't be any interference. You can also set different priorities and weight for 2 records that are used for the very same service, but forward to different servers for redundancy or load balancing. By having an SRV record you can employ your domain 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 customer of yours will use is determined by the priority and weight values which you have set.