An DiscoveryUrl has the form:
scheme: the protocol used to establish a connection.
port: the TCP port on which the Server is to be found.
path: additional data used to identify a specific Server.
The scheme maps onto SRV record service field.
The following mappings are defined at this time:
The first two are OPC UA service names assigned by IANA.
Additional service names may be added in the future.
The endpoint shall support the default transport profile for the scheme.
The hostname maps onto the SRV record target field.
If the hostname is an IPAddress then it shall be converted to a domain name.
If this cannot be done then LDS shall report an error.
The port maps onto the SRV record port field.
The path maps onto the path string in the TXT record (see Table 69).
Suitable default values should be chosen for fields in a SRV record that do not have a mapping specified in Table 70. e.g. TTL=86400, class=IN, priority=0, weight=5