IBM AS/400 manual Optimizing communications performance, Improving wide area network performance

Page 13

Chapter 3. Optimizing communications performance

Many factors can affect the performance of AS/400 application programs. To achieve the best performance with your particular communications environment, you may want to review these topics:

vImproving wide area network (WAN) performance.

vImproving local area network (LAN) performance.

vImproving data path performance.

Improving wide area network performance

To achieve better performance with your AS/400 when communicating in a wide area network (WAN), you need to consider the following:

v“Adjusting WAN protocols for optimum AS/400 performance”

v“Adjusting the WAN line speed for optimum AS/400 performance”

v“WAN line speed considerations for IOPs” on page 8

Adjusting WAN protocols for optimum AS/400 performance

Wide area network (WAN) protocols affect the communications performance on AS/400. Let us use X.25 for our example. For each X.25 communications controller, the AS/400 has some processing limitation for the line, the line speed, and the total number of virtual circuits that can be used. Performance degradation can be reduced by observing these limitations.

To optimize AS/400 performance for wide area networks, perform these tasks:

vReduce the total number of frames by using larger frames.

vTo take advantage of these large frame sizes, change the MAXFRAME parameter on the line description (LIND) to reflect the maximum value. For X.25, increase the DFTPKTSIZE and MAXFRAME parameters to their maximum value.

vConfigure a WAN line as full-duplex to provide you with a higher throughput for applications that can take advantage of this mode. This can also provide higher throughput for multiple users.

vIncrease frame relay to capacity.

The data rate for a given protocol may increase as frame size increases. Under these circumstances, the central processing unit (CPU) and the input/output processor (IOP) do not do as much processing. Fewer and larger frames also make more efficient use of the communications line (higher effective data rate) because of fewer overhead bytes and line turn-arounds.

Frame relay has equivalent performance over RS449, X.21, and V.35 assuming equal line speeds and conditions. Frame relay performance (CPU time) is similar to or slightly better than Synchronous Data Link Control. For properly tuned large transfer applications, the CPU and IOP have no problem using the line speed to capacity.

For information about configuring AS/400 communications, see the Communications Configuration book.

Adjusting the WAN line speed for optimum AS/400 performance

In many cases, the communications line is the largest contributor to overall response time in the wide area network (WAN). Therefore, you should closely plan and manage its performance. In general, having the appropriate line speed is the key consideration for gaining the best performance.

To adjust the line speed for your wide area network, perform these tasks:

vCheck the difference in performance between half-duplex utilization and full-duplex utilization on the line description.

© Copyright IBM Corp. 1998, 2001

7

Image 13
Contents ERserver Page ERserver Page Contents Troubleshooting communications problems Part 1. Getting started with AS/400 communications Version Print this topic Version Creating a network interface description Configuring AS/400 for communicationsCreating a network server description Creating a line descriptionVersion Adjusting the WAN line speed for optimum AS/400 performance Adjusting WAN protocols for optimum AS/400 performanceOptimizing communications performance Improving wide area network performanceWAN line speed considerations for IOPs Adjusting LAN lines for optimum communications performance Adjusting LANs for optimum communications performanceImproving local area network performance Improving data path performance LAN line speed considerations for IOPsAddcmne SBSDlibname/sbsname DEVdevname* MODEmodename Set up the communication entries Example Communications subsystem configurationCommunications performance considerations for batch jobs Example Interactive subsystem configurationMixing interactive and batch jobs on a WAN line Performance considerations for AnyNet communications Setting up the AnyNet environmentAnyNet communications for the AS/400 system Qusrwrk SubsystemsVersion User written Appc applications Communications applicationsDistributed data management DDM Version Communications applications Version Matching AS/400 parameters for a host system Communicating with host systemsSSAP/DSAP/remote-adapter-address Name Rmtcpname Vtamlst Sscpname Maxframe Group MaxdataRmtnetid Vtamlst Netid Ssap SapaddrLcllocname Dfhtct Netname Mode Modeent LogmodeLocadr Locaddr Locpwd Dfhtct BindpwdAS/400 Host Definition AS/400 Prompt Examples Connecting AS/400 to a host systemModd Modeent Logmode Cosd Modeent COSCommunicating with host systems Version Communicating with host systems Version Configuring the host controller description Configuring dependent LU requester DlurConfiguring the device descriptions Version AS/400 Remote AS/400 AS/400 Prompt Communicating with a remote AS/400 systemAdptadr AdrinsertAS/400 Remote AS/400 AS/400 Prompt Parameter Cnnnbr Netadr X25DCECnnpwd Dsap SsapLinkpcl InlcnnRmtcpname Lclcpname Rmtnetid LclnetidConnecting one AS/400 to another AS/400 system Version Communicating with a remote AS/400 system Version Matching AS/400 parameters for 5494 controllers Communicating with remote workstation controllersLAN AS/400 5494 Prompt AS/400 Parameter Field Subfield ValueRmtcpname RmtnetidLinktype LAN AS/400 5494 Prompt AS/400 Parameter Field SubfieldMatching AS/400 parameters for a 5494 connected by Ethernet AS/400 5494 Prompt Parameter Field Subfield Value Version LAN Adptadr Matching AS/400 parameters for a 5494 connected by Sdlc Prompt Parameter Field Subfield AS/400 Value AS/400Field Subfield AS/400 Value Communicating with remote workstation controllers Matching AS/400 parameters for a 5494 connected by Linktype Example Connecting AS/400 to a 5494 controller connected byIBM 5494 Remote Control Unit Planning Guide, GA27-3936 Linkpcl Qllc DftpktsizeEllc NetlvlField Subfield Value AS/400 5494 PromptCommunicating with remote workstation controllers Matching AS/400 parameters for 3x74 controller 3174 AS/400 Configuration PromptMatching AS/400 parameters for a 3174 controller Questions3174 AS/400 Configuration Prompt Parameter Questions Matching AS/400 parameters for a 3274 controller Switched Short-Hold ModeNRZ or Nrzi Encoding Control Unit Address3274 AS/400 Example Connecting an AS/400 to a 3174 control unitPrompt Parameter Number Matching AS/400 parameters for 470x finance controllers Matching AS/400 parameters for finance controllersAS/400 AS/400 Prompt Parameter Macro AS/400 AS/400 Prompt Matching AS/400 parameters for Fbss finance controllersMacro Parameter Service access point for PC Switched lineLine mode PC addressIdentification block and Identification number Service access point for Host/37xx/4700Matches the Fbss Identification number Data Link ControlMatching AS/400 parameters for retail controllers Example Connecting AS/400 to a finance networkAS/400 Definition AS/400 Prompt Parameter Statement Matching AS/400 parameters for 3651 retail controllersAS/400 Parameter Sdlclin Bit Bit Value AS/400 Definition AS/400 Prompt3684 AS/400 Definition Prompt Matching AS/400 parameters for 3684 retail controllers3684 AS/400 Definition Prompt Parameter AS/400 Parameter Linecon Bit Bit Value Matching AS/400 parameters for 4680/4690 Line parameterCNN*MP SNBU*NO SNBU*YES MODEMRATE*FULLMatching AS/400 parameters for 4680/4690 Link parameter Exchid parameter specified on the AS/400 Crtctlrtl commandAS/400 Prompt AS/400 Parameter Line Parameter CNNMatching AS/400 parameters for 4684 retail controllers Wire constant RTS?Local node Hex Remote node HexExamples Connecting AS/400 to a 4690 retail controller Version Communicating with remote workstation controllers Version Displaying message queues to solve communication problems Troubleshooting communications problemsQsysarb Job logs and communication problemsQpasvrp Solving communication problems using communications traceTrace option setting System service tools and communication problemsTrace full Solving communication problems using the system problem logConsiderations for system tuning during error recovery Solving communication problems using status informationUsing error messages to aid in error recovery Solving communication problems using reason codesReason Code Reason Description Reason Codes for Rejected Program Start RequestsReason Code Reason Description Advanced Peer-to-Peer Networking Networking conceptsDependent LU requester support Advanced program-to-program communicationsHPR architecture option sets High-performance routingInternetwork packet exchange support What is TCP/IP What is Systems Network ArchitectureLocal area network standards Common networking standardsATM on AS/400 Distributed data interface networkToken-ring networks Wireless networkAsynchronous communications Wide area network standardsBinary synchronous communications Frame relay networksSynchronous data link control network Integrated services digital networkIsdn data link control network Network Version
Related manuals
Manual 489 pages 47.95 Kb Manual 516 pages 58.6 Kb

AS/400 specifications

The IBM AS/400, now known as the IBM iSeries, is a midrange computer system that has been a cornerstone of enterprise computing since its introduction in 1988. Designed to provide a robust platform for business applications, the AS/400 is celebrated for its reliability, scalability, and integrated database capabilities.

One of the key features of the AS/400 is its Integrated Operating Environment, which blends hardware and software resources seamlessly. This integration allows businesses to execute diverse workloads, ranging from traditional applications to modern web-based services, all on a single platform. The operating system, OS/400 (now IBM i), offers a rich set of APIs and tools for developers, simplifying application development and management.

Another standout characteristic of the AS/400 is its built-in database, DB2 for i. This powerful relational database management system allows for efficient data handling and provides advanced features such as support for SQL, XML, and JSON, making it easier for businesses to manage their data and integrate it with other systems. The database's tight integration with the operating system enables high performance and security.

In terms of scalability, the AS/400 can accommodate small businesses as well as large enterprises, with the ability to support hundreds of users simultaneously. Its architecture allows for easy upgrades in hardware, meaning that organizations can scale their systems without replacing the entire infrastructure.

Security is another critical attribute of the AS/400. With a sophisticated security model, it offers built-in user authentication, access control, encryption, and auditing capabilities to protect data and applications from unauthorized access.

The AS/400 also supports multiple programming languages, including RPG, COBOL, Java, and PHP, giving organizations the flexibility to choose the development tools that best fit their needs. This diversity helps maintain legacy applications while also developing new ones that leverage modern technologies.

Moreover, the platform supports both traditional green-screen interfaces and modern graphical user interfaces, allowing organizations to transition smoothly into contemporary user experience paradigms.

Overall, the IBM AS/400 stands out as a resilient, flexible, and secure computing platform that enables organizations to effectively manage their business operations, streamline processes, and adapt to changing market demands. Its unique combination of integrated features and capabilities ensures that it remains relevant in today's fast-paced technology landscape.