The Topology tab allows you to delegate domains and provide domain hints.

When an Oracle Names server delegates domains within its region, it creates a hierarchy of Oracle Names servers to serve an administrative region more efficiently. The Oracle Names server effectively creates a new domain when it does this.

For example, the Oracle Names server for the domain acme.com is having performance problems because the domain acme.com has too many clients and too many services for one Oracle Names server to handle. In this situation, the administrators of the acme.com decide to create a new domain name, us.acme.com. They create a new Oracle Names server for this domain, and then they instruct the first Oracle Names server to delegate the domain us.acme.com to the new Oracle Names server, thus lowering the traffic for the first Oracle Names servers.

Domain hints are useful when an Oracle Names server is getting a lot of requests for services in a particular foreign region. Usually, when a Oracle Names server gets a request for a service name in a foreign region, it forwards it on to whatever foreign Oracle Names servers it knows, who then reforward the request to the root Oracle Names servers in its region. This server will contact other region root Oracle Names servers, and the request will then be reforwarded to Oracle Names servers which has information on the domain that the request refers to. However, if there are a lot of requests for data in a certain foreign area, a hint can be provided to your Oracle Names server that information on this area can be found in its Oracle Names server, which can be reached at a specified address. This way, network traffic is reduced, no requests fail, and clients make their connections more rapidly.

Action

Delegate Domain:	Click to delegate a domain. Specify the domain in the Domain Name field, the Oracle Names server name and address in the Names Server Name and Names Server Address fields.
Domain Hint:	Click to provide a domain hint for the Oracle Names server. Specify the domain in the Domain Name field, the Oracle Names server name and address in the Names Server Name and Names Server Address fields.
Execute button:	Click to perform the DB Link query, add or remove operation

Topology

Domain Name:	Enter the domain name to delegate a domain or provide a domain hint.
Name Server Name:	Enter the Oracle Names server name.
Name Server Address:	Enter the Oracle Names server address.