This event is used by multicast nodes to announce which port(=channel) they communicate on. This may be something they want or not want to share with the rest of the world for security reasons. Therefore this is an optional event. 

If several channels is used several events is sent.

Typically this event is sent on the multicast announce channel

 | Byte | Description    | 
 | :----: | -----------    | 
 | 0    | MSB of channel | 
 | 1    | LSB of channel | 
 | 2-5  | Reserved       | 
