Expand Configuration and Management Manual (H06.21+, J06.10+)

Subsystem Description
Expand Configuration and Management Manual — 529522-013
17 - 45
Incoming Traffic Flow
After the reply message is successfully processed, the message system routes the
reply message to the appropriate process, and the Expand line-handler process
releases the buffer pool used by the reply message.
$NCP and Passthrough Packets
An incoming $NCP packet is a packet received from the $NCP at a neighbor node and
destined for the $NCP of the local node. An incoming passthrough packet is a packet
received from a remote node and destined for another remote node.
When the Expand line-handler process receives a $NCP or a passthrough packet, it
buffers the packet in its buffer pool. If the packet is a passthrough packet, the Expand
line-handler process routes the packet to the outgoing Expand line-handler process
that can most efficiently transmit the packet to its destination node. If the packet is a
$NCP packet, the Expand line-handler process routes the packet to the local $NCP.
After the packet has been routed to the appropriate process ($NCP or Expand line-
handler), the Expand line-handler process releases the buffer pool used by the packet.
Note. For more information on outgoing $NCP and passthrough packet handling, see $NCP
and Passthrough Traffic Flow on page 17-41.