Use the Domain Resolver API to perform DNS lookups of SIP URIs using the RFC 3263 protocol. These lookups can be performed synchronously if you want to avoid having to preserve state in order to handle an asynchronous callback. They can also be performed asynchronously if you need a better performing interface.
getServletContext().getAttribute("com.ibm.ws.sip.container.domain.resolver")
@resource DomainResolver resolver
DomainResolver locate(SIPURI)
DomainResolver locate(SIPURI, Listener)
For more information about this API, expand the Reference > Programming interfaces > APIs - Application Programming Interfaces section in the Feature Pack for Communications Enabled Applications Information Center navigation. Then scroll down to the com.ibm.ws.sip.container.domain.resolver API.
For more information about DNS servers, see the topic Using DNS procedures to locate SIP servers