Chapter 12 - Network Communications on z/os
Objectives In this chapter, you will learn: An overview of the communication network model layers The software components of the z/os Communications Server product The difference between a VTAM subarea and APPN network topology How the IP network can be used to transport data between SNA applications. Commonly used TCP/IP and VTAM commands 2
IBM Communications Server z/os Applications Applications Applications RPC TCP/IP Sockets APPC APPC SNA Sockets RPC 3
Open Systems Interconnect (OSI) network model Layered Network Models TCP/IP OSI SNA telnet, np, SNMP, SMTP Applications Presentation Session Transaction Services NAU Services Mgr Func. Mgmt Data Srvc Data Flow Control TCP UDP Transport Transmission Control IP ARP RARP ICMP Network Path Control Data Link Data Link Data Link Control Physical Physical Physical 4
TCP/IP introduction Network A xseries Router Network B zseries Gateway pseries Router zseries xseries Router xseries Gateway Workstation pseries Workstation Workstation 5
Interconnecting TCP/IP networks Router Gateway Router Router Bridge Gateway Network A Network B INTER-NETWORK 6
Internet addressing IPv4 Host B Gateway IP Address 193.15.6.4 Host A IP Address 131.12.8.2 Network 131.12 IP Address 131.12.8.1 Network 193.15.6 Host C IP Address 193.15.6.3 131.12 8.2 IP address = x.x.x.x (32 bits) = <net-id> <host addr> Class A = <x> <x.x.x> xx> 193.15.615 3 network ID host Class B = <x.x> <x.x> Class C = <x.x.x> <x> network ID host address address 7
TCP/IP commands TCP/IP Commands can be entered TSO ready prompt ISPF Command Shell Prefixing the command with TSO on any ISPF command line. NETSTAT PING TRACERTE NSLOOKUP TELNET FTP z/os UNIX shell prompt (prefix o =command) onetstat 8
VTAM overview - the SNA environment 317x Cluster controller Host processor z/os CICS VTAM pseries AIX PC Windows zseries iseries zseries OS/400 z/vm Communication controller (37xx) NCP Workstations 9
A pure VTAM subarea network VTAM (SSCP) Subarea Configuration VTAM subarea (1) SSCP (PU Type 5) LU (CICSTS1) LU (IM S1) VTAM subarea (2) SSCP (PU Type 5) LU (CICSTS2) LU (IM S2) NCP subarea (11) PU Type 4 LU PU Type 2 New York City LU LU LU Los Angeles Chicago PU Type 2 NCP subarea (13) PU Type 4 NCP subarea (12) PU Type 4 VTAM subarea (3) SSCP (PU Type 5) LU (CICSTS3) LU (IM S3) PU Type 2 PU Type 2 LU LU LU LU 10
APPN topology VTAM (CP) APPN Configuration VTAM APPN CP (PU Type 5) LU (CICSTS1) LU (IM S1) OSA HPR/IP OSA HPR/IP VTAM APPN CP (PU Type 5) LU (CICSTS2) LU (IM S2) router PC New York City Los Angeles PC PC Internet and /or intranet Internet segment Chicago PC internet segment router router OSA HPR/IP Internet segment VTAM APPN CP (PU Type 5) LU (CICSTS3) LU (IM S3) PC PC PC PC 11
Common VTAM commands Displays VTAM startup options. D NET,VTAMOPTS Displays communication storage usage. D NET,CSM[,OWNERID=ALL] Displays status of defined applications (ACBs). D NET,APPLS Displays status of VTAM activated ATCCONxx members. D NET,MAJNODES Displays APPN topology information. D NET,TOPO,LIST=SUMMARY Displays status of APPN CP-CP sessions. D NET,CPCP Displays status of subarea SSCP-SSCP sessions. D NET,SESSIONS Displays status of subarea cross domain resource managers. D NET,CDRMS Displays status of VTAM exit points. D NET,EXIT 12
Summary In this chapter, you have learned: An overview of the communication network model layers Software components of the z/os Communications Server product The difference between a VTAM subarea and APPN network topology How the IP network can be used to transport data between SNA applications. Commonly used TCP/IP and VTAM commands 13