Session Manager can locally resolve host names into an ordered set of IP address, port, and transport tuples and assigns priority and weights to each tuple. Local Hostname Resolution is only applied to host names provisioned by the administrator and overrides normal DNS resolution. For example, if Session Manager is attempting to resolve nj.proxy.avaya.com, and the host name is provisioned as a local host name, Session Manager will skip the DNS resolution and instead determine the request target using the tuples for nj.proxy.avaya.com.

To route a SIP INVITE, Session Manager needs the IP addresses corresponding to the Fully Qualified Domain Name (FQDN) in the INVITE. To resolve a host name by replacing it with its IP address, Session Manager checks for the host name on the local network. If the host name cannot be resolved through broadcasting on the local network, Session Manager searches for the host name in the host names file or by querying the DNS server that maintains the host name to IP address mapping.