Tn3270 3270 Without the SNA A presentation for: TPF Users Group October 18, 2005 Copyright: Copyright: John Rojewski [email protected].

tn3270tn32703270 Without the SNA3270 Without the SNA

A presentation for:A presentation for:TPF Users GroupTPF Users GroupOctober 18, 2005October 18, 2005

Copyright:Copyright:John RojewskiJohn Rojewski

[email protected]@aexp.com

October 2005October 2005 American ExpressAmerican Express 22

With Appreciation to:With Appreciation to:

Ken BroganKen Brogan

Gary CuppawheGary Cuppawhe

W David JacksonW David Jackson

Tom LipmanTom Lipman

Special Thanks to:Special Thanks to:

Tom Cornelisse and KLMTom Cornelisse and KLM


tn3270tn3270 OverviewOverview Why Continue to Invest in 3270?Why Continue to Invest in 3270? How do we use tn3270?How do we use tn3270? How long do we use this product?How long do we use this product? Technical Architecture and Major ComponentsTechnical Architecture and Major Components What is “Open Source”?What is “Open Source”? How can Open Source best be utilized and How can Open Source best be utilized and

controlled?controlled? Makeover: Before and After ResultsMakeover: Before and After Results ReferencesReferences


OverviewOverview

This project began in April 2005 and was installed This project began in April 2005 and was installed into Production on September 14, 2005.into Production on September 14, 2005.

This direction was dictated by the announcement of This direction was dictated by the announcement of a desire to remove the 3745 (SNA/NCP) a desire to remove the 3745 (SNA/NCP) communications processors from American communications processors from American Express.Express.

We heard that other shops had started to use We heard that other shops had started to use tn3270 server software residing in TPF.tn3270 server software residing in TPF.


Historical PerspectiveHistorical PerspectiveIBM 3270IBM 3270

Remember 1975?Remember 1975? 24 lines by 80 24 lines by 80

characterscharacters Protected fieldsProtected fields Highlight and invisible Highlight and invisible

fieldsfields Auto cursor positioningAuto cursor positioning Row column addressingRow column addressing

American Express started supporting 3270 data American Express started supporting 3270 data streams within TPF in 1979. We are still supporting streams within TPF in 1979. We are still supporting 3270 today in 2005.3270 today in 2005.


Why Continue to Why Continue to Invest in 3270?Invest in 3270?

We have already invested heavily in 3270. With We have already invested heavily in 3270. With almost 25 years of development, WWCAS has a almost 25 years of development, WWCAS has a bundle of 3270-based applications, and hundreds bundle of 3270-based applications, and hundreds of screens.of screens.

The tn3270 solution allows the continued usage of The tn3270 solution allows the continued usage of that investment, without the need for the SNA that investment, without the need for the SNA network that is being dismantled.network that is being dismantled.


How do we use tn3270?How do we use tn3270?

The tn3270 source is ‘C’ code, and is compiled to be The tn3270 source is ‘C’ code, and is compiled to be loaded into TPF.loaded into TPF.

The tn3270 server receives requests from The tn3270 server receives requests from (amazingly) tn3270 client software packages (amazingly) tn3270 client software packages running on user workstations.running on user workstations.

We just need to load the code to TPF and activate it, We just need to load the code to TPF and activate it, and re-configure the tn3270 software clients to and re-configure the tn3270 software clients to access it.access it.


How long do we use How long do we use this product?this product?

This is a transitional product.This is a transitional product.

We will utilize this in the interim between removal We will utilize this in the interim between removal of the SNA 3745 controllers and the of the SNA 3745 controllers and the decommissioning of the last 3270-based decommissioning of the last 3270-based application.application.

The is not an end-point. The is not an end-point.

We will continue to move toward browser-based We will continue to move toward browser-based presentations.presentations.


Technical Technical Architecture Architecture

IBM

sna.telnet.com

tpf.telnet.com

SNA

OSA Port 1023TN3270 Client

PersonalCommunicator orHost On Demand

TN3270 ClientPersonal

Communicator orHost On Demand

SNA LU 2Network

Connection

TCP/IPNetwork

Connection

Connect to:sna_telnet_server

Conect to:tpf_telnet_server

TPF tn3270Server

NormalTPF SNA

CASAAppl

Existing tn3270 client workstations connect directly to WWCAS TPF hostvia new Server address (tpf.telnet.com). TN3270 Server software (new)interfaces with existing applications through SNA (YA8-ZA8) ApplicationInterface.


Major ComponentsMajor Components

Host SoftwareHost Software YTNT – ‘C’ DLM (from Open Source)YTNT – ‘C’ DLM (from Open Source) YTEL – ‘C’ DLL (from Open Source)YTEL – ‘C’ DLL (from Open Source) YR78 – Assembler RVT Interface (Proprietary)YR78 – Assembler RVT Interface (Proprietary) CLTX – ZINET “listener” (IBM)CLTX – ZINET “listener” (IBM) Interfaces to existing SNA application routersInterfaces to existing SNA application routers Various changes to issuers of ROUTC macroVarious changes to issuers of ROUTC macro

Client SoftwareClient Software IBM Host-on-Demand (HOD)IBM Host-on-Demand (HOD) IBM Personal CommunicationsIBM Personal Communications


What is “Open Source”?What is “Open Source”?

We did not write the tn3270 source code. We We did not write the tn3270 source code. We received it via something called ‘Open Source’.received it via something called ‘Open Source’.

Open Source consists of programs written by non-Open Source consists of programs written by non-employees that are ‘free’ for anyone to use.employees that are ‘free’ for anyone to use.

Open Source programs are distributed on the Open Source programs are distributed on the Internet with Software Licenses, like the Internet with Software Licenses, like the GNU/GPL.GNU/GPL.


Open Source PromiseOpen Source Promise

The open-source movement is helping to turn The open-source movement is helping to turn significant chunks of the Information Technology significant chunks of the Information Technology (IT) infrastructure into commodities by offering (IT) infrastructure into commodities by offering free alternatives to proprietary software.free alternatives to proprietary software.

Open Source provides the capability to utilize these Open Source provides the capability to utilize these alternatives with minimal impact to already busy alternatives with minimal impact to already busy schedules. Pre-built and tested, these packages schedules. Pre-built and tested, these packages are potential “Gold Mines”.are potential “Gold Mines”.


Open Source Open Source CharacteristicsCharacteristics

Open source is founded upon several key Open source is founded upon several key characteristics:characteristics:

Access - Free access to source codeAccess - Free access to source code Redistribution - Ability to freely copy and Redistribution - Ability to freely copy and

distributedistribute Modification - Can create new versionsModification - Can create new versions Integrity - Ethical practices and policies (no Integrity - Ethical practices and policies (no

“hidden agendas”)“hidden agendas”) Equality - Equal access, equal useEquality - Equal access, equal use License - No requirement for an additional License - No requirement for an additional

license, not specific to a particular product, no license, not specific to a particular product, no restrictions placed on other software in restrictions placed on other software in distributiondistribution


Open Source ConcernsOpen Source Concerns

Open Source thrives on "Take and Give Back" Open Source thrives on "Take and Give Back" principle. principle.

It is generally expected that organizations using It is generally expected that organizations using open source also contribute to the open source open source also contribute to the open source either by fixing some open bugs or add more either by fixing some open bugs or add more features to the existing code. features to the existing code.

However, existing organization policies may not However, existing organization policies may not allow developers to contribute back to the open allow developers to contribute back to the open source community.source community.


Open Source Open Source Best PracticesBest Practices

It is a best practice to wrap the open source It is a best practice to wrap the open source software by providing a custom interface, and software by providing a custom interface, and then ask applications to use that interface. then ask applications to use that interface. • This approach is particularly valuable for future This approach is particularly valuable for future

upgrades or a complete replacement of the adopted upgrades or a complete replacement of the adopted software with another one.software with another one.

It is strongly recommended that open source It is strongly recommended that open source software is used “as is”, without modifying the software is used “as is”, without modifying the open source implementation. open source implementation. • If necessary, complementary functionality that enhances If necessary, complementary functionality that enhances

an open source product should be integrated with--not an open source product should be integrated with--not embedded within--the implementation. embedded within--the implementation.

• This approach facilitates maintenance and support and This approach facilitates maintenance and support and the ability to upgrade to future versions of the software the ability to upgrade to future versions of the software more easily.more easily.


Open Source Open Source Adoption ProcessAdoption Process

The software adoption is not free, even if the software is! The software adoption is not free, even if the software is! Hence, a careful evaluation must be done if the cost of Hence, a careful evaluation must be done if the cost of adoption (checking for licensing, doing various reviews and adoption (checking for licensing, doing various reviews and training) is cost effective over simply buying a commercial training) is cost effective over simply buying a commercial product or even custom building the same. product or even custom building the same.

Check with your Software Governance Teams before Check with your Software Governance Teams before beginning the evaluation of open source software. There beginning the evaluation of open source software. There may already be a standard solution that meets the may already be a standard solution that meets the identified requirements and can be used immediately.identified requirements and can be used immediately.

Involve your Software Governance Teams in the review of Involve your Software Governance Teams in the review of Open Source IT.Open Source IT.

Try not to adopt the latest version, unless it is stable. Try not to adopt the latest version, unless it is stable. Adopt the version just before the latest version, unless it is Adopt the version just before the latest version, unless it is deemed to be unstable or error prone.deemed to be unstable or error prone.

Consider the user base of the open source software. If you Consider the user base of the open source software. If you are the only one who is adopting it, then you could be are the only one who is adopting it, then you could be inviting trouble.inviting trouble.


Buy versus BuildBuy versus Build The decision on whether to build software versus The decision on whether to build software versus

acquiring software should be made using a sound acquiring software should be made using a sound economic model. economic model.

True costs of software development and the True costs of software development and the savings that result from reuse should be savings that result from reuse should be evaluated. Costs include:evaluated. Costs include:• Listing Requirements for the component.Listing Requirements for the component.• Searching, acquiring, and testing the component to Searching, acquiring, and testing the component to

validate that it meets the requirements.validate that it meets the requirements.• Integrating the component into the application.Integrating the component into the application.• Customizing the component to meet the specific Customizing the component to meet the specific

application requirements.application requirements.


Open Source Open Source Assessment CriteriaAssessment Criteria

The need for an Open Source Assessment Checklist The need for an Open Source Assessment Checklist is essential to a quality experienceis essential to a quality experience• Features of productFeatures of product• Risks to acquiring or failure to acquireRisks to acquiring or failure to acquire• Alternatives worth investigatingAlternatives worth investigating• Licensing DetailsLicensing Details• Vendor DetailsVendor Details• Support DetailsSupport Details• Quality AssessmentQuality Assessment• Stability AssessmentStability Assessment• Security AssessmentSecurity Assessment• Notable Gaps in any of the aboveNotable Gaps in any of the above


Assessment QuestionsAssessment Questions

Examples of questions to be asked regarding Examples of questions to be asked regarding assessment of Open Source product might assessment of Open Source product might include:include:

Is there a programmer's guide available Is there a programmer's guide available explaining the usage of this component? explaining the usage of this component?

Is the change history for this component well Is the change history for this component well documented? documented?

Is the component independent of other open Is the component independent of other open source components? source components?

Are there formal API specifications available for Are there formal API specifications available for the component identified? the component identified?

Etc.Etc.


ConclusionsConclusions Any and all developers that work on an open-Any and all developers that work on an open-

source product that has been altered (by said source product that has been altered (by said developers) must be able to access detailed developers) must be able to access detailed information concerning modifications; doing so information concerning modifications; doing so requires rigorous documentation. requires rigorous documentation.

Licensing models currently in use for open source Licensing models currently in use for open source must be understood for each project under must be understood for each project under consideration.consideration.

A well-defined process should be employed when A well-defined process should be employed when adopting open source components and/or adopting open source components and/or services. services.


ConclusionsConclusions Companies should strongly consider adopting any Companies should strongly consider adopting any

open source tools that help in improving open source tools that help in improving productivity. productivity.

Under most circumstances, infrastructure Under most circumstances, infrastructure software should only be adopted if there is software should only be adopted if there is backing and support provided by a reliable third backing and support provided by a reliable third party company.party company.

Service levels for open source software have Service levels for open source software have proven to be comparable, and at times superior proven to be comparable, and at times superior to proprietary software to proprietary software


Before and AfterBefore and After



QuestionsQuestions??


Additional ReferencesAdditional References SourceForge SourceForge

http://cvs.sourceforge.net/viewcvs.py/tn5250/tn5http://cvs.sourceforge.net/viewcvs.py/tn5250/tn5250/src/250/src/

TELNET RFC TELNET RFC http://www.faqs.org/rfcs/rfc854.htmlhttp://www.faqs.org/rfcs/rfc854.html TELNET 3270 RFC TELNET 3270 RFC

http://www.faqs.org/rfcs/rfc1041.htmlhttp://www.faqs.org/rfcs/rfc1041.html TN3270 Enhancements RFC TN3270 Enhancements RFC

http://www.faqs.org/rfcs/rfc1647.htmlhttp://www.faqs.org/rfcs/rfc1647.html Open Source Development Open Source Development

http://www-306.ibm.com/software/htp/tpf/tpfug/tgs03/tgs03u.pdf



Thank you for your time.Thank you for your time.

Please forward any comments and/or suggestions Please forward any comments and/or suggestions to:to:

[email protected]@aexp.com

Tn3270 3270 Without the SNA A presentation for: TPF Users Group October 18, 2005 Copyright: Copyright: John Rojewski [email protected].

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