3 Designed as a collection of Sets of Rules

                  +-----+  
                  | EMS |  
                  +-----+  
                  | NTS |  
 +-----+-----+    +-----+-----+-----+-----+-----+-----+  
 | DPS | MCS |    | FNS | ACS | LRS | CIS | DPS | MCS |  
 +-----+-----+----+-----+-----+-----+-----+-----+-----+  
 |      IMS       |                DBS                |  
 +----------------+-----------------------------------+  
 |  IP multicast  |             IP (unicast)          |  
 +----------------+-----------------------------------+