Path: news1.ucsd.edu!ihnp4.ucsd.edu!agate!howland.reston.ans.net!math.ohio-state.edu!uwm.edu!lll-winken.llnl.gov!apple.com!seeding.apple.com!user From: garryh@seeding.apple.com (Garry Hornbuckle) Newsgroups: comp.sys.mac.comm Subject: Open Transport FAQ part 1 (General Info) Date: Tue, 31 Oct 1995 08:43:17 -0800 Organization: Apple Computer, Inc. Lines: 270 Message-ID: NNTP-Posting-Host: seeding.apple.com Apple Open Transport Frequently Asked Questions Part One - General Information Extracted from: Open Transport Background Q & A Version 1.8 (OT 1.0.8 Release) October 19, 1995 General Information Q: What is Apple Open Transport? A: Apple Open Transport is the modern networking and communications subsystem for the Mac(tm) OS. Open Transport is based on industry standards and brings a new level of networking connectivity, control, and compatibility to MacOS systems, while preserving and enhancing the hallmark of the Macintosh and MacOS - built-in support for easy-to-use networking. Q: What long-range Apple goals are advanced through Open Transport? A: Apple believes that communications and collaboration technologies are integral and fundamental to personal and workgroup computing. With Open Transport our goal is to provide the foundation to make the MacOS the best desktop OS for multiprotocol networking, anywhere. Q: What needs must be addressed to be "the best"? A: Networking and communications technologies are mission critical - thus reliability is a base-level requirement. Organizations require interoperability in heterogeneous environments; full compliance with standards is necessary. High performance is also key. Increasing file sizes - often related to the rich media types found in graphics and publishing, multimedia, video production, and technical markets - create a demand for effective use of higher bandwidth communications technologies such as ISDN, FDDI, fast ethernet and ATM. Beyond these base-level requirements network managers, end-users and developers each have additional needs. * Network managers need networked systems to support a flexible model of administration that accommodates both centralized and decentralized management models. * Users are typically more interested in using communications as a basis for productivity applications. As such, they want networking that is easy to set up and easy to use. This becomes even more important when users are mobile, needing access to networking services from wherever they may be - without requiring complex reconfiguration for each connection type. * Developers need to address the broadest possible markets with minimum incremental investment. In short, they need standards-based, cross-platform APIs and development tools. Q: What were some of the key goals driving the development of Open Transport? A: Apple began with two key assumptions: that networking is inherently a multiplatform, multiprotocol proposition; and that customers cannot (and should not have to!) start over to achieve networking interoperability. This led us to adopt five key design goals: * Open Transport must protect customer and developer investments in existing network infrastructure and applications. * Open Transport must be based on existing cross-platform industry standards. * Open Transport must provide users with an easy to set-up, easy to use abstraction of the underlying complexity of multiprotocol networking. * Open Transport must also provide a complementary abstraction of networking and communications services for applications developers. * Open Transport must offer a flexible run time model - one that lets a specific protocol be configured and selected at run time, rather than linked at compile time. Key Features and Benefits Q: How will Open Transport benefit users? A: Open Transport provides individual computer users with many benefits. Two of the most immediately visible and important benefits relate to making networking more accessible. First, Open Transport makes it easy to switch from one network configuration to another. A computer user "on the go" might want to hook up to the Internet in various locations, each requiring a different network configuration. With Open Transport settings for each network location can be stored for easy access and use. Changed settings are available immediately - no reboot of the computer is required to use the new configuration. Second, Open Transport integrates on-line help, based on AppleGuide(tm) technology, to make it easier for an individual to hook up to an network, with fewer demands on network manager and support resources. Q: How will Open Transport benefit network managers and organizations? A: Open Transport provides significant new flexibility in setting up network configurations; with Open Transport, the network manager can recommend or require configuration settings for users on the network, or allow users to determine their own settings. Open Transport also improves support for centralized configuration management. For example, Open Transport/TCP supports the Dynamic Host Configuration Protocol (DHCP), allowing network managers to administer addressing and other TCP/IP configuration information from a central server. Q: How will Open Transport benefit developers? A: Open Transport is designed to make it easier and more cost-effective to develop Macintosh-based applications for a wide variety of customers and markets. With Open Transport the MacOS has built-in networking and communications based on cross-platform industry standards, including the POSIX compliant X/Open Transport Interface (XTI), UNIX STREAMs and Data Link Provider Interface (DLPI). Applications written to support Open Transport can directly support a wide range of networking environments (serial, dial-up network, LAN, and WAN), and multiple protocols (AppleTalk, TCP/IP, serial, and others) from a common code base. This capability is sometimes referred to as transport independence. Q: What is transport independence? Why is it important? A: Different people judge networking in different ways. End-users focus on what they can do using the network, and tend to select applications based on functionality and ease of use. Network managers are interested in delivering reliable network services in a cost efficient manner. Developers want to create compelling functionality for users, but are strongly influenced by the availability of networking infrastructure. Unfortunately, with current networking tools and systems developers are forced to tie their applications to specific network infrastructure requirements - driven by their API choices. This creates a potential conflict between individual and organizational needs. If network managers restrict protocols to control support costs, users may not have access to the applications they need. If user require specific applications they may increase support costs for the network manager by "dragging along" specific network infrastructure requirements. Developer are stuck in the middle, making decisions for both users and network managers by selection of an API at compile time. Transport independence is a concept that breaks this undesirable linkage. When implemented, it allows developers to write to a uniform set of APIs, users to focus on selecting the best applications, and network managers to make independent decisions about network infrastructure, all on an ongoing basis. Q: What benefits can be realized from transport independent applications? A: For end-users, transport independence brings an increased freedom to select applications that meet their needs, without being concerned with the bits and bytes of networking protocols. For network managers, transport independence allows increased flexibility in designing and controlling infrastructure demands arising from support of end-user applications, i.e., the freedom to manage the bits and bytes of networking protocols. Developers who create transport independent applications will find access to broader markets with incremental resources; code written for the AppleTalk market, for example, can be delivered to TCP/IP markets as well. Q: How does Open Transport enable transport independence? A: Open Transport brings together four technologies to support the development and deployment of transport independent applications on the MacOS: * a set of look-and-feel guidelines that promote consistency for configuration of network services across protocols, * a unified set of cross-platform, standards-based APIs for all networking and communications protocols; for example, applications can send and receive data over an AppleTalk LAN or the TCP/IP-based Internet using the same programming interfaces, * a dynamic link-and-load architecture and set of protocols; protocols are loaded and unloaded on demand, conserving system resources, and making it possible to substitute TCP for ADSP at the application launch time (for example), and * an addressing and naming support tool box; for example, applications can open a communications end-point by name (i.e., "seeding.apple.com" or "printer16:LaserWriter@sales"; Open Transport will automatically provide the appropriate name-to-address mapping services (i.e., DNR, NBP, etc.). Together these support the creation of transport independent applications on the MacOS. Q: Are all Open Transport applications transport independent? A: No. While Open Transport provides the necessary foundation, there are certain guidelines and programming practices required for developers to create transport independent applications. For example, most protocols have many features in common - but also some features that are protocol-specific. If an application depends on a protocol-specific feature, then it will depend upon that protocol as well. In some cases it may be appropriate or desirable to develop a transport-specific application. For example, an MBone client is currently only useful when communicating using TCP/IP. Q: Does transport independence imply that my organization can offer "AppleTalk services" without supporting "AppleTalk protocols"? A: For each service and network environment, protocol and services choices will be determined by a combination of factors; transport independence is only one of them. This begins with both the client and the server implementations of the particular service of interest (file, print, e-mail, directory, security, back-up, calendar, etc.) supporting the Open Transport APIs. Next, both the client and server must have the protocol stack(s) of choice installed. Finally, the server application must include some administration utility to allow the network manager to specify the protocol(s) over which application and/or presentation layer services are to be provided. The user experience for selecting the server (i.e., "Choosing", or "name-binding") may vary depending on the underlying protocol. For example, AppleTalk offers a distinctive user experience through the "Chooser" and the underlying NBP/ZIP protocols. TCP/IP offers a substantially different model for name-to-address translation (DNS); NetWare/IPX still another (NDS). For More Information Q: How can interested parties get more information on Open Transport? A: Documentation for Open Transport is publicly available by anonymous ftp on the Internet at ftp://seeding.apple.com/opentransport/. There you will find release notes, general information (including the latest version of this Q&A), and developer notes from the SDK. Q: How can interested customers apply to receive pre-release copies of Open Transport for implementation testing? A: The Open Transport Early Access program was announced in March 1995. Based on the overwhelming customer response this program is now enrolled to capacity - no further applications can be accepted or approved. Alternatively, you should contact your local Apple Computer support representative concerning locally supported seeding programs. The final Open Transport 1.1 software will be available in the near future. Q: How can interested developers apply to receive pre-release copies of Open Transport for development and testing? A: The Open Transport developer seeding program has reached over 5,000 developers to date. As the final code for Open Transport 1.1 is nearing completion, Apple will move to make the Open Transport Software Developers Kit (SDK) widely available through electronic information services, including select sites on the Internet. The Open Transport SDK will also be included on the next issue of the MacOS SDK, available from APDA. To further pre-release seeding of the Open Transport 1.1 SDK is planned at this time. Following the shipment of version 1.1, a new seeding program is planned for future versions of Open Transport. Details of additional seeding programs will be announced at a later date. Q: How can developers get support while developing Open Transport applications? A: Open Transport is a strategic and supported technology. Apple Developer Support services have engineering specialists fully trained on Open Transport development and debugging. Access to these engineers is just one of the benefits of the Apple Developer Partner's program. For more information on Apple's Developer Support services, including information on how to register as an Apple Developer Partner, contact the Macintosh Developer Services Information Line at US +1(408) 974-4897. For developers who are not a part of one of Apple's Developer Support services programs, the Open Transport engineering team has established an email address for general feedback: opentpt@applelink.apple.com. This address is not for technical support, however, nor can all inquiries can be acknowledged. Q: Are there general reference sources on XTI, STREAMs and DLPI? A: Sources of information that are applicable to XTI and STREAMs include: * OSF/1 Operating System: Network Applications Programmer's Guide; Open Software Foundation, Prentice Hall, ISBN 0-13-640145-7 * UNIX Network Programming; W. Richard Stevens, Prentice Hall, ISBN 0-13-949876-1 * UNIX System V Release 4: Programmer's Guide: STREAMs; Unix Press (A Prentice Hall title), ISBN - 0-13-020660-1 * Programming UNIX SVR4.2: Network Programming Interfaces; UNIX Press (A Prentice Hall title), ISBN 0-13-017641-9 * X/Open CAE Specification: X/Open Transport Interface (XTI); X/Open Company, Ltd. (XO/CAE/91/600) ISBN 1-872630-29-4 * Transport Provider Interface Specification, rev 1.5 (92/12/10); UNIX International, OSI Special Interest Group * Data Link Provider Interface Specification, rev 2.0.0 (91/08/20); UNIX International, OSI Work Group ------------------------------------------------------------------- Garry Hornbuckle Product Manager, Communications & Collaboration ------------------------------------------------------------------- "If I told you that I | email garryh@seeding.apple.com spoke only for myself | applelink HORNBUCKLE1 would you believe me?" | fax (408) 974-1211 ------------------------------------------------------------------- .