HP-UX SNAplus2 General Information Edition 2 J2740-90015 HP 9000 Networking E1098 Printed in: United States © Copyright 1998 © Hewlett-Packard Company, 1998.
Legal Notices The information in this document is subject to change without notice. Hewlett-Packard makes no warranty of any kind with regard to this manual, including, but not limited to, the implied warranties of merchantability and fitness for a particular purpose. Hewlett-Packard shall not be held liable for errors contained herein or direct, indirect, special, incidental or consequential damages in connection with the furnishing, performance, or use of this material. Warranty.
This software is based in part on the Fourth Berkeley Software Distribution under license from the Regents of the University of California. ©copyright 1980, 1984, 1986 Novell, Inc. ©copyright 1986-1992 Sun Microsystems, Inc. ©copyright 1985-86, 1988 Massachusetts Institute of Technology. ©copyright 1989-93 The Open Software Foundation, Inc. ©copyright 1986 Digital Equipment Corporation. ©copyright 1990 Motorola, Inc.
Contents Preface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Prerequisite Knowledge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7 About This Book. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7 Organization of This Book . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7 Typographic Conventions. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Contents Benefits Provided by SNAplus2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Easy Migration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Easy Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . User Interface Choices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Client/Server Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Preface The HP-UX SNAplus2 General Information document contains an introduction to SNAplus2 and explains key product concepts and features. Prerequisite Knowledge Before reading this manual, you should have a knowledge of SNA and APPN concepts. See the Related publications section for details of manuals that provide this information. About This Book This section explains how information is organized and presented in this book.
Typographic Conventions Table 1, shows the typographic styles used in this document. Table 1 Typographic Conventions Special Element Sample of Typography Document title HP-UX SNAplus2 Administration Guide Command or HP-UX utility vi SNAplus2 Publications SNAplus2 publications include user guides, administrator guides, and programmer guides. The following sections describe the contents of each book.
HP-UX SNAplus2 and TN3270 Glossary Provides a comprehensive list of terms and their definitions used in the SNAplus2 library. Publications for Administrators SNAplus2 provides the following administrator guides: HP-UX SNAplus2 Installation Guide Explains how to install the SNAplus2 software and set up system files. HP-UX SNAplus2 Upgrade Guide Provides information about upgrading to the current version of SNAplus2 from previous versions.
Publications for Programmers SNAplus2 provides the following programmer guides. Each guide includes conceptual and detailed reference information. HP-UX SNAplus2 APPC Programmers Guide Contains the information you need to write application programs using Advanced Program-to-Program Communication (APPC). HP-UX SNAplus2 CPI-C Programmers Guide Contains the information you need to write application programs using Common Programming Interface for Communications (CPI-C).
Related Publications For information about SNA, APPN or LU 6.2 architecture, refer to the following IBM documents: • IBM Systems Network Architecture: LU6.2 Reference: Peer Protocols SC31-6808 • IBM Systems Network Architecture: APPN Architecture Reference SC30-3422.
1 SNA Networking 13
SNA Networking Overview Overview SNAplus2 provides Systems Network Architecture (SNA) networking support for HP-UX systems. SNA is a set of protocols devised by IBM to facilitate communications between computers. Over the years, SNA has evolved considerably. Initially, SNA was heavily oriented towards accessing host computers, and relied on the host to control the entire network.
SNA Networking Components of a Subarea Network Components of a Subarea Network A simple subarea network includes the following components. Node A node is a component or a computer that participates in an SNA network. SNA defines different node types for different roles in the network. Host A host is a mainframe computer compatible with the original IBM System/370. A host is a type 5 node.
SNA Networking Components of a Subarea Network A diagram of a subarea network looks like an inverted tree, as shown in Figure 1-1, “SNA Subarea Network.” Figure 1-1 SNA Subarea Network The root of the tree (at the top of the diagram) is the host computer that controls the network. The branches are the communications links. The leaves (at the bottom of the diagram) are the terminals or printers attached to the network and accessed by users.
SNA Networking Components of a Subarea Network Subarea SNA Node Components This section describes the logical SNA components in a subarea network. The host node contains the following elements: SSCP The host node contains a system services control point (SSCP) that is responsible for managing network resources. Its jobs include activating and deactivating sessions between host and remote components.
SNA Networking Components of a Subarea Network Additionally, the SSCP establishes a session to the remote LU (the SSCP-LU session). The SSCP-LU session is used to control and manage both the LU itself and the session between the host and remote LUs. The remote LU uses the SSCP-LU session to request the SSCP to establish a session between the host and remote LUs (the LU-LU session). When a session is requested, the SSCP manages the host LU to establish the LU-LU session with the remote LU.
SNA Networking SNA and APPN SNA and APPN As well as including subarea networks, many networks today also use APPN. A purely APPN network is decentralized. It is made up of interconnected nodes that communicate as peers across local and wide-area networks. A sample APPN network is shown in Figure 1-2, “Portion of a Sample APPN Network.
SNA Networking SNA and APPN Except for LEN nodes, each node in an APPN network contains a control point (CP) that is responsible for managing the node and its resources. A CP in one APPN node can establish a session with the CP in an adjacent node. These CP-CP sessions are used to exchange network information that enables resources to be located dynamically.
SNA Networking SNA and APPN Each network node includes a control point that can establish a CP-CP session with any other adjacent network node, and with any adjacent end node for which the network node is the network node server. LEN Nodes In Figure 1-2, “Portion of a Sample APPN Network,” the EN low entry networking (LEN) node is a type 2.1 node. It contains the most basic functionality necessary for connection to an APPN network.
SNA Networking Mixed SNA Networks Mixed SNA Networks Although APPN networks do not require a host to control resources in the network, hosts often participate in APPN networks. APPN has been implemented on many host platforms, enabling the hosts to perform as network nodes in the APPN network; at the same time, the host provides an SSCP to control subarea SNA functions. Many SNA networks reflect their history, containing elements of both subarea SNA and APPN.
2 Introducing SNAplus2 23
Introducing SNAplus2 Overview Overview SNAplus2 is a software product that enables HP-UX computers to communicate with remote computers (IBM mainframes, PCs, or other HP-UX computers) within an IBM SNA network. It provides SNA node type 2.0 and 2.1 support for communicating with host and peer computers; it also implements an APPN node, providing end node or LEN node function, depending on its configuration. (See “SNAplus2 Components”.
Introducing SNAplus2 SNAplus2 Components SNAplus2 Components SNAplus2 implements an APPN node to communicate with other nodes on the SNA network. This provides LU 6.2 support for APPC and CPI-C capabilities, as well as LU 0, 1, 2, and 3 support for 3270, RJE, and LUA communications. The SNAplus2 node can operate as a LEN node, or an end node, depending on its configuration. Certain functions are supported only on network nodes, or only on network and end nodes, as defined by the APPN architecture.
Introducing SNAplus2 SNAplus2 Resources SNAplus2 Resources Node resources define the communications capabilities of the APPN node, including connectivity resources (ports and link stations), LUs (type 0–3 for 3270, RJE, and LUA communications, and type 6.2 for APPC and CPI-C communications), modes, and directory information. Domain resources are available to all of the SNAplus2 systems in the local network; such resources are used to support particular user programs.
Introducing SNAplus2 SNAplus2 Resources multiple ports for a single adapter. In this case, the different ports are distinguished by addresses such as the service access point (SAP) number. Link stations A link station (LS) represents the logical path through the SNA network between the SNAplus2 local node and a remote computer.
Introducing SNAplus2 SNAplus2 Resources Such a network is referred to as a shared-access transport facility (SATF). However, to enable direct communications between two nodes, you need to define link stations between every pair of nodes; this results in a very large number of link station definitions if you want to enable any two nodes on the SATF to communicate directly.
Introducing SNAplus2 SNAplus2 Resources can also be dependent LUs, if they are used to communicate with host computers that use older versions of SNA host software. Type 6.2 LUs that are used to communicate with peer computers, or with newer SNA software on host computers, are referred to as “independent LUs.” They can support multiple user sessions simultaneously.
Introducing SNAplus2 SNAplus2 Resources In addition, you might need to specify requirements for the communications path between the LUs, such as enforcing a certain level of network security, minimizing transmission time, or avoiding the use of expensive communications links.
Introducing SNAplus2 SNAplus2 Resources User Applications SNAplus2 provides the following user applications: 3270 Emulation Program SNAplus2 provides 3270 emulation software that lets users log on to and use IBM host systems from HP-UX computers. Using this software, a user can transfer files between the local and host computers, and control display and printer emulation sessions.
Introducing SNAplus2 SNAplus2 Resources The RJE workstation uses the node's type 0–3 LU resources. In addition, SNAplus2 requires definitions for the RJE workstations on the system. RJE workstation definitions are configured in the domain configuration file. In addition to the SNAplus2 configuration, the operation of the workstation is controlled by a workstation style file, which is maintained by the users of the workstation.
Introducing SNAplus2 SNAplus2 Resources MS applications provide Management Services functions for network management. An application can be either NMVT-level or MDS-level, depending on the type of MS data it sends and receives. SNAplus2 performs any data conversion that is required. NOF applications NOF applications administer SNAplus2 configuration and management resources.
Introducing SNAplus2 SNAplus2 Resources CSV applications Common Service Verb (CSV) applications provide utility functions such as character translation and application trace control. The APIs for APPC, CPI-C, LUA, HLLAPI, NOF and CSV are included both on SNAplus2 systems and on HP-UX and Windows clients. HLLAPI, NOF and MS APIs are only available on HP-UX systems (both servers and clients). Many third-party Windows emulation programs supported by SNAplus2 include HLLAPI support.
Introducing SNAplus2 SNAplus2 Resources PU Concentration Normally, a dependent LU session requires a direct communications link to the host computer. However, a node running SNAplus2 that has a direct communications link to the host can also provide PU concentration facilities to LUs on downstream computers, enabling them to access the host over the communications link from the SNAplus2 node. The downstream computer must contain an SNA PU type 2.0 or 2.1 to support dependent LUs at the host.
Introducing SNAplus2 SNAplus2 Resources computers connected to SNAplus2 over a local token ring network, so that they all access the same long-distance SDLC leased line from SNAplus2 to the host. Using PU concentration also simplifies the configuration at the host, because there is no need to define the downstream computers and the communications links to them.
Introducing SNAplus2 SNAplus2 Resources The SNAplus2 TN server function is shown in Figure 2-2, “TN Server.” Figure 2-2 TN Server TN server provides an association between a TN3270 user and a 3270 LU on the SNAplus2 server. All data from the TN3270 user is routed to the LU. This means that the configuration for both the host and the TN3270 user is as though they were connected directly; neither needs to be aware that data is being routed through TN server.
Introducing SNAplus2 SNAplus2 Resources Client/Server Support Computers running SNAplus2 can be configured to communicate using client/server protocols. When client/server protocols are used in a network, all the computers using client/server protocols to communicate in that network are referred to as a “domain.” Each computer in the network specifies the same domain name when SNAplus2 is installed.
Introducing SNAplus2 SNAplus2 Resources HP-UX Clients A client computer does not contain an SNA node; it holds only the information it needs to access servers on the SNAplus2 LAN, and relies on a server to provide the necessary configuration information. Most of the details of using HP-UX clients are the same as those for a server, except that the client has no node resources to define and manage. Windows Clients SNAplus2 enables machines running Microsoft Windows 3.
Introducing SNAplus2 Benefits Provided by SNAplus2 Benefits Provided by SNAplus2 SNAplus2 provides features and benefits that range from simplifying configuration and improving problem diagnosis to enhancing network performance. Easy Migration When upgrading an older version of SNAplus2 to Release 6, you can preserve your present system configuration by using the SNAplus2 migration utilities. The migration utilities support all of the earlier versions of SNAplus2.
Introducing SNAplus2 Benefits Provided by SNAplus2 ASCII Administration Program A menu-based ASCII administration program is available for character-based terminals. The ASCII interface provides a subset of all functions available through the Motif Administration Program and can be used for configuration and management of SNAplus2. The ASCII program is used through the HP ObAM environment.
Introducing SNAplus2 Benefits Provided by SNAplus2 NOF API All SNAplus2 administration tools, including the Motif administration program and the command-line administration program, use the NOF API to configure and manage SNAplus2 resources. You can use the NOF API to implement your own administration functions. Configuration information is stored in a plain text file that can be modified using standard HP-UX utilities such as vi, awk, and sed.
Introducing SNAplus2 Benefits Provided by SNAplus2 Better Performance SNAplus2 optimizes network speed by using different traffic-management methods that balance traffic flow according to network size. For larger networks, you can use the connection network option to improve communication efficiency. The connection network option creates a communications path directly between nodes. Using a connection network enables traffic to bypass intermediate network nodes, resulting in faster session establishment.
Introducing SNAplus2 Benefits Provided by SNAplus2 Security Options With networks becoming more complex and moving to an open architecture, security emerges as a major issue. In SNA networks running SNAplus2, you can protect your assets by defining various levels of security through configuration and by implementing certain types of links. LU 6.
Introducing SNAplus2 Benefits Provided by SNAplus2 SNMP-MIB, which is adapted for APPN networks from TCP/IP, is a distributed management service based on an agent-manager architecture. This management scheme uses several components: one or more SNMP agents, a manager, and a MIB database, all of which typically reside on different nodes. The manager and agent communicate with each other by using the SNMP protocol. • An SNMP agent is a process that runs on and monitors the status of the system being managed.
Introducing SNAplus2 Benefits Provided by SNAplus2 • Status and error messages to guide you through configuration routines and system operation • Service logs for collecting network error and failure information • Trace facilities for gathering and formatting detailed problem information • A data collection utility for gathering problem data to provide to service personnel.
3 SNAplus2 Networking Solutions 47
SNAplus2 Networking Solutions Overview Overview SNAplus2 can be used in a variety of configurations to provide solutions to a number of networking requirements. In this chapter, the possible network evolution of an imaginary bank, called “Global Bank,” is used to illustrate the kinds of real life networking requirements that might arise in a typical organization.
SNAplus2 Networking Solutions Host-Based SNA Network Host-Based SNA Network Each branch of Global Bank is connected to an SNA host at the bank's headquarters. The bank's network started off as a simple host-based SNA network on one site, as shown in Figure 3-1, “Traditional Host-Based SNA Network.
SNAplus2 Networking Solutions Using Multiple Servers Using Multiple Servers As the bank's headquarters grow, the headquarters need to be linked to computers in the regional branches of the bank. The host and its applications represents one of the bank's largest and oldest investments, but an increasing processing load means that the host and its communication links are becoming a bottleneck for operations.
SNAplus2 Networking Solutions Using Multiple Servers In this configuration, the host continues to run the bank's central mission-critical applications, while the bank expands its network by using a single SNAplus2 server to support a number of clients over a LAN. The SNAplus2 server is a high-performance product that can be scaled to meet the needs of the network as the processing requirements increase.
SNAplus2 Networking Solutions Adding a Second Server Adding a Second Server The load on the SNAplus2 server increases as more clients are added to the network in the local branch of the bank. The bank invests in a second SNAplus2 server that runs in parallel to the first, as shown in Figure 3-3, “LAN with Two SNAplus2 Servers.” Adding a second server enables local load-balancing across the two servers; the second server also provides a hot-backup capability.
SNAplus2 Networking Solutions Adding a Second Server The local branch achieves scalable load balancing by defining LUs on both servers and assigning all of those LUs to one LU pool. The applications on the clients are configured to use an LU from that pool. If no LUs are available on one server, the client automatically uses an LU that is available on the second server.
SNAplus2 Networking Solutions Adding APPN Capability Adding APPN Capability As the local branch diversifies into the financial services sector, the bank wishes to integrate new peer-based applications into its existing network while maintaining its existing investment in corporate host-based applications.
SNAplus2 Networking Solutions Adding APPN Capability The original SNAplus2 servers can connect simultaneously to both APPN and pre-APPN nodes. The server provides PU concentration functionality to downstream LUs. PU concentration enables host-based SNA applications to be run on the APPN network, while reducing the number of links required to the host in a fashion that is completely transparent-both to the host and to the downstream LU.
SNAplus2 Networking Solutions Integrating an Existing TCP/IP Network Integrating an Existing TCP/IP Network To further expand its services, Global Bank takes over a smaller bank that has an existing TCP/IP network. As a result, the bank needs to integrate that TCP/IP network into Global Bank's corporate network, as shown in Figure 3-5, “Mixed SNA and TCP/IP Network.
SNAplus2 Networking Solutions Integrating a Windows-Based PC Network Integrating a Windows-Based PC Network Global Bank acquires a subsidiary that has an existing Windows-based PC network. As a result, the Windows-based PC network needs to be integrated into Global Bank's corporate network. Figure 3-6 SNA Network with Connectivity to a Windows-Based PC Network The SNAplus2 server provides the communications link to the host.
SNAplus2 Networking Solutions Enterprise SNA Network Enterprise SNA Network After adding all of the branch offices described in this chapter, the Global Bank's entire network is configured as shown in Figure 3-7, “Enterprise SNA Network.” This network configuration enables users to communicate across different networks seamlessly, supporting Global Bank's investment in centralized host-based applications at the same time that it enables off-loading of branch processing to the local offices.
Index Numerics 3270 LU for TN server, 37 A adaptive session-level pacing, 43 APPN network example, 19 ASCII Administration Program, 41 B backup server, 38 C client, 38 client/server support, 38 command-line administration program, 41 connection network option, 43 CPI Communications, 46 D display functions, 46 documentation set, 8 domain, 38 domain name, 38 dynamic configuration, 41 E entry point, 44 F fiber optic connectivity, 43 focal point, 44 I interface choices, 41 M manager application, 45 manual set
