Meeting the Challenge of Managing Client/Server Document Distribution and Printing. PrintXchange White Paper Xerox Corporation

Transcription

1 Meeting the Challenge of Managing /Server Document Distribution and Printing PrintXchange White Paper 1999 Xerox Corporation

2 You glance at the clock. Good. Just enough time to print out the report you ve run and the presentation you ve been working on all day and get to the BIG meeting. You send them to the printer that is in the building the meeting is in and receive confirmation the document was printed. What planning! You have time to return some important calls before you leave. You walk over to the next building with enough time to swing by the printer and pick them up, bind the report and set up the presentation before everyone arrives. Sounds like things are under control, right? Wrong. The documents aren t there. You run back to your office to check the print manager on your PC, but it says the printer is idle. You panic and send the job again, this time to a different (B&W only) printer right down the hall from your office because you don t have time for color to print out. You run down to that printer and find that it is already busy printing other jobs. How many jobs are ahead of yours? No way to tell! Meanwhile, right next to the printer you selected is a second printer sitting idle. "Why can t this system route to a printer that is not busy?" you wonder, "And why can t I ever get an accurate status for a job I have printed?" Does this sound familiar? Today, document distribution and distributed print management protocols are inadequate to meet client server printing needs. The fact that these services are implemented differently in the major distributed computing platforms only compounds the customer s network resource management problem. The problem promises to get worse over time unless the industry changes the way it provides customers with basic network services. Why? Because businesses increasing rely on client server applications to manage mission critical business applications. As they do so, they find that the industry has not provided them with software tools and products to enable IT to manage the migration of document distribution and printing applications from legacy systems to client server environments. How significant is this problem? According to a survey by BIS Strategic Decisions of LAN system administrators, a top complaint managing LAN operations was printer contention and problem resolution. According to an informal survey of large corporate companies, many mainframes are still maintained solely because printing cannot be rightsized. One particular IT Director of a large bank estimates that 30% of the company s MIS budget is spent on printing related issues. As more and more business applications migrate to client server platforms, their operational challenges increase. The center of the database market has moved swiftly from mainframes to Midrange, UNIX and NT server systems. As databases move, so too does the processing of business applications. UNIX and NT servers and TCP/IP networks have become the network backbone for production client server applications. This shift in computing paradigms is having a significant impact on enterprise printing applications. What do customers want and need? Minimally, end users want to be informed of the status of their print jobs, notified if there s a problem, or able to reroute their print jobs --no matter where in the enterprise they originally directed their job to be printed Increasingly, applications that emit reports, statements, and other computer generated documents without operator involvement will be directing that output to other network services residing on distributed network nodes. The builders of those applications will require consistent ways of naming, finding, and aggregating the resources necessary to produce, audit, and account for the job. Systems Administrators and IT network management personnel will be required to do remote problem solving on print resources distributed on their networks. They will be required to do traffic analyses to determine peak load demand to resolve contention problems. Applications developers will be required to develop new classes of production applications that distribute then print, print on demand, or distribute for viewing with print options. And, they will be directed by their management to develop those applications so as not to be dependent upon any specific manufacturer s platforms. PrintXchange steps up to the challenge

3 Xerox is addressing these customer needs by building PrintXchange, a common implementation of a distributed print service. The PrintXchange server currently runs on Sun Solaris, Compaq Tru64 Unix, and Windows NT Server. To ensure interoperability, all PrintXchange systems are based on the same source code pool and the APIs and portability libraries will be standard on all platforms. PrintXchange is designed to enable printer manufacturers, system vendors, ISVs and system integrators to develop and bring to market conformant printers and value added applications. The architecture, APIs and portability libraries have been designed to allow server support to span UNIX and NT operating systems while client submission is supported from almost any operating system -- UNIX, Windows NT and 95/98 and Mac OS to name a few. PrintXchange will appeal to a wide variety of audiences including the following: CIO s struggling with the cost and frustration of managing a heterogeneous computing environment and creating a print management and document distribution strategy that takes advantage of the company s IT investments. PrintXchange will allow them to more easily manage printing as well as provide the foundation for better resource and cost management. System managers and LAN administrators who manage networked printing, but have no central control of the different devices on their network. PrintXchange provides a single point of control for all of the printers on their network and allows advanced configuration options that allow greater flexibility in routing and scheduling of jobs. Users eager for additional capabilities and flexibility from their printing infrastructure. PrintXchange will allow them to more easily utilize resources on the network. The print service will allow users to print and share information with others when and where they need, freeing up more time to spend on adding value to their jobs and documents. System Integrators - PrintXchange represents a new business opportunity for system integrators and value-added resellers. PrintXchange provides a platform on which to incorporate new functionality in next generation applications and build value-add printing applications that capitalize on their customers IT and printer investments. System Vendors have been struggling for some time with the complexity of implementing and supporting client/server enterprise-wide computing. PrintXchange provides the standard architecture foundation for interoperability and plug-and-play functionality the industry is demanding. Printer Manufacturers - By incorporating and supporting PrintXchange into their printer design, printer manufactures will easily be able to support a variety of applications, operating and networking systems. Built Using Standards Xerox is developing PrintXchange to the ISO standard for networked document distribution and printing services and the POSIX standards for application interfaces and command line interface (CLI). Since PrintXchange is built on such open standards, other companies can build conformant printers and other value added products. All of the specifications, technologies and products built into PrintXchange will be designed to preserve compatibility with existing printing services and applications. Xerox, with more than two decades of experience in distributed computing print services from research and development conducted at its Palo Alto Research Center, is applying its vast understanding of printing technology to PrintXchange. Xerox has developed the PrintXchange spooler and clients including developing, publishing and supporting PrintXchange Application Programming Interfaces (APIs), Command Line Interfaces (CLIs) and Graphical User Interfaces (GUIs). The PrintXchange Distributed Printing Model The cornerstone of a distributed print system such as PrintXchange is its ability to distribute printing functions in a networked heterogeneous computing environment. In such an environment, a user expects the ability to print anywhere on the network and to be informed about the status of his or her job during the printing process.

4 Furthermore, this idea of distributed computing also applies to the management of this print system. System managers may manage the distributed components and devices from one or more management centers in the network. Conceptually, this is not difficult to envision. However, its implementation is considerably more complex. The print system must be scaleable and modular to support flexibility in deployment. Additionally, the print system must interface seamlessly with the operating system for performance purposes. Lastly, the print system must interface with such network infrastructure services as directories, security, and transport level protocols to function natively as a network service. PrintXchange is designed with such modularity and integration in mind. PrintXchange is organized around three primary functions: those that implement the print system itself, those that provide the network interface, and those that provide the operating system interface. The functional organization into printing, network, and operating system is key to providing portability and interoperability of the PrintXchange print system. The PrintXchange Print System SAP R/3 Interface GUI CLI CLI SDK API Lpr, Lpr, LM, LM, NetWare, NetWare, & & IPP IPP Inbound Inbound Gateways Gateways O/S O/S Filter and Accounting API s Spooler Infrastructure Network Network Filter API Supervisor Front End DDK API XPP XPP Lpq/lprm Lpq/lprm Lpr Lpr Stream Stream CPAP CPAP DocuShare DocuShare Fax Fax... Output Devices DocuPrint NPS DocuSP Generic lpd DocuCentre Family DocuPrint N Family Serial & Parallel CPAP Printer WEB Repository Remote Fax Figure 1. Illustrates the relationship of the PrintXchange print system modules The PrintXchange print system consists of three distinct system software modules based on the Palladium print system of MIT Project Athena. These modules include a client program that initiates print system requests, a spooler that operates on print system requests as well as stores data to be printed, and a print supervisor that operates on print system requests as well as controls one or more output devices. Each PrintXchange program can run independently on any node of a network or any and all modules of PrintXchange can run on a single node of a network. This allows the PrintXchange components to actually be distributed and running on a number of systems in a number of different locations. This flexibility is needed to distribute the computing load and enable a distributed print system. In addition, this design modularity ensures that

5 systems vendors, printer manufacturers and application developers have enormous flexibility in product designs which will result in scaleable and interoperable products to address changing customer requirements. The software modules interoperate via the PrintXchange print system protocol which includes the current versions of the ISO protocol for printing documents and the POSIX extensions for print system management. The protocol is datastream independent and supports bi-directional conversations between print service modules. Network Infrastructure PrintXchange is designed to be independent of underlying network protocols. This independence allows porting to, and interoperation with, multiple network protocols. PrintXchange uses an abstracted network interface to support the needs of the print system components (i.e., the client, the spooler, the supervisor, and the library). The abstracted network interface is designed so that support using different network protocols (e.g. TCP/IP, IPX/SPX, DECnet, OSI, etc.) can be added without changing the other print system components. PrintXchange is designed to be independent of the underlying operating system. This independence allows porting to different operating systems and platforms. The modularity of this design directly benefits other systems vendors who license the PrintXchange distributed print service because it enables them to tune the service to the unique characteristics of their operating systems. Summary The promise of open systems computing in which network services provide the foundation for application interoperability has been an elusive goal for the computer industry. With the PrintXchange distributed print system, Xerox is providing a system level resource that represents significant progress toward the attainment of this industry objective.