If a server ID is not specified, the server creates a server ID based on the server's port. The HTTP socket port is used in the creation of the server ID unless the server is only running SSL, in which case the SSL socket port is used. For example, if the default port of 5061 is being used the server ID would be 5061xx. The xx characters uniquely identify the server processing on the port. When the server is started with multihome disabled, the xx characters are always spaces. When multihome is enabled, the xx characters range from 'A ' to 'ZZ'. The xx characters will always be the same for a specific IP address.
If this is missing, the default case will be used.
Only one entry may exist in the master server configuration file. If more than one entry is found, the last one will be used.