Addressing

A Service address consists of two parts, assigned by the developer

• A Service Type number – typically hard-coded
• A Service Instance number – often calculated by user in run time

A service address is always qualified by a scope indicator

• Indicating lookup scope on the calling side
node == 0 indicates cluster global lookup
node != 0 indicates that lookup should be performed only on that node
• Indicating visibility scope on the binding side
There are dedicated values for node local or cluster global visibility

There are almost no restrictions on how to bind service addresses

• Different service addresses can be bound to same socket
• Same service address can be bound to different sockets
• Service address ranges can be bound to a socket
• Only one service address per socket in message bus mode
• This address type is also used for sending datagram and
  communication group multicast
  
  

A client doesn't need to know the location of the server

• Translation from service address to socket address is performed on-the-fly at the source node.
• There is a replica of the global binding table on each node for performing this translation.
• A sender can still indicate an explicit socket address when that is more practical,. e.g., when just responding to an incoming message.