Expand Configuration and Management Manual (G06.24+)

Contents

Expand Configuration and Management Manual—523347-008

xvi

18. Subsystem Description (continued)

Expand Subsystem and the OSI Reference Model 18-9

Expand Line-Handler Process Layer Functions 18-10

$NCP Layer Functions 18-12

Path Function of the Expand Subsystem 18-13

Protocol Packet Types 18-13

Packet Synchronization 18-16

Example of End-to-End Protocol Packet Exchanges 18-16

Layer 4 Send Window 18-21

Routing and Time Factors 18-22

Setting Time Factors 18-23

Negotiating Path Time Factors 18-24

Best-Path Route Selection 18-24

Network Routing Table (NRT) and Multiple Path Table (MPT) 18-25

Calculating Route Time Factors 18-27

Routing Algorithms 18-28

Multi-CPU Paths 18-31

Multi-CPU Routing Examples 18-34

Message Handling and Buffer Allocation 18-38

Outgoing Traffic Flow 18-38

Incoming Traffic Flow 18-42

Message Buffering 18-46

Global Variables 18-47

Stack 18-47

Control Blocks 18-47

Line Buffer 18-47

Buffer Pool 18-47

Shared Memory Area for QIO 18-48

Expand-to-NAM Interface 18-49

Network Access Method (NAM) Processes 18-49

Connection Establishment 18-50

Sending and Receiving Data 18-52

Expand-to-IP Interface 18-54

NonStop TCP/IP Processes 18-54

Expand-over-IP Connection Establishment 18-55

Sending and Receiving Data 18-57

Forwarding Expand-over-IP Packets to Other Expand Line-Handler

Processes 18-58