5.3.3.2 Common functions...............................................................................................................76
5.3.3.3 Message queues....................................................................................................................77
5.3.3.4 Semaphores..........................................................................................................................78
5.3.3.5 Shared memory regions........................................................................................................79
5.3.4 Signals..........................................................................................................................................80
5.3.4.1 Data structures......................................................................................................................80
5.3.4.2 Algorithms...........................................................................................................................80
5.3.5 Sockets.........................................................................................................................................81
5.4 Network subsystem..............................................................................................................................82
5.4.1 Overview of the network protocol stack.......................................................................................83
5.4.2 Transport layer protocols..............................................................................................................85
5.4.2.1 TCP......................................................................................................................................85
5.4.2.2 UDP.....................................................................................................................................85
5.4.3 Network layer protocols...............................................................................................................85
5.4.3.1 Internet Protocol Version 4 (IPv4).......................................................................................86
5.4.3.2 Internet Protocol Version 6 (IPv6).......................................................................................86
5.4.3.3 Transition between IPv4 and IPv6........................................................................................88
5.4.3.4 IP Security (IPsec)................................................................................................................88
5.4.4 Internet Control Message Protocol (ICMP)..................................................................................93
5.4.4.1 Link layer protocols.............................................................................................................93
5.4.5 Network services interface...........................................................................................................93
5.4.5.1 socket().................................................................................................................................94
5.4.5.2 bind()....................................................................................................................................94
5.4.5.3 listen()..................................................................................................................................96
5.4.5.4 accept().................................................................................................................................96
5.4.5.5 connect()..............................................................................................................................96
5.4.5.6 Generic calls.........................................................................................................................96
5.4.5.7 Access control......................................................................................................................96
5.5 Memory management...........................................................................................................................97
5.5.1 Four-Level Page Tables...............................................................................................................99
5.5.2 Memory addressing....................................................................................................................100
5.5.2.1 System x.............................................................................................................................101
5.5.2.2 System p.............................................................................................................................108
5.5.2.3 System p native mode........................................................................................................115
5.5.2.4 System z ............................................................................................................................123
5.5.2.5 eServer 326........................................................................................................................134
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