IPv4/IPv6 Multicast Option

• The IPv4 Multicast Option or IPv6 Multicast Option are used by the server to announce the IPv4 or IPv6 multicast address, the transport layer protocol (ISO/OSI layer 4), and the port number the multicast events and multicast notification events are sent to.
  服務器使用IPv4 Multicast Option或者IPv6 Multicast Option來分別通知IPv4或IPv6多播地址，傳輸層協議（ISO / OSI第4層）和端口號，用來作為發送多播Event和多播notification event的目的地址。

• As transport layer protocol, only UDP is supported.
  作為傳輸層協議，僅支持UDP。

• IPv4 Multicast Options shall be only referenced by SubscribeAck entries, describing the multicast destination IP address and port multicast events shall be sent to.
  IPv4 Multicast Options只能由SubscribeAck entry引用，描述發送多播Event的目的地IP地址和端口。

• The Port Number field [16 bits] of the IPv4 Multicast Option Options shall carry the port number for transporting Multicast Events of the Eventgroup.
  IPv4 Multicast Option的Port Number字段[16位]應攜帶用于傳輸Eventgroup的多播Event的端口號。

• The same rules apply for IPv6 SD Endpoint Option.