Networked Services Project
Request for Tender for NLA Networked
Services
Chapter 4 - Project Capabilities Sought
4.3 HTTP/Z39.50 Gateway
4.3.2 Mapping to Configurations
4.3.3 General Capabilities Sought
4.3.4 Specific Capabilities Sought
4.3.6 Links to Other Configurations
4.3.1 Overview
It is envisaged that an HTTP/Z39.50 Gateway (hereafter referred to as 'the Gateway') serve as a single point of management for all online search traffic, both chargeable and free. In this capacity the Gateway could perform both entry management functions such as user authentication and session control, as well as track user activity information, to be passed on directly to the Administrative Support System (Configuration #5), as illustrated in the Systems Architecture chapter (Chapter 1, Figure 1.1).
In addition to the above, the Gateway will perform the usual translation function to allow searching from various Web browsers to multiple Z39.50 capable databases, through a Z39.50 Client included within the Gateway package. The principal purpose of the Gateway will therefore be to allow the users a transparent mechanism for a uniform search capability across a diverse range of target data sources, each with its own search engine and specific syntax and functionality of search.
An increasing number of providers of library catalogues, abstract and index databases, and other Web based resources have started to offer Z39.50 Server capabilities. In Stage 1 of the Networked Services Project, these target data sources will be the National Bibliographic Utility, external Z39.50 resources on the Internet and (possibly) the Integrated Library Management System. In later stages of the Project, the Gateway will be able to act as a single point of access to other services sought by the Library eg, hosted databases, digital object services, and directory services.
Although Z39.50 is ratified by both the US standards body (ANSI) and the International Standards Organisation (ISO), there is a wide divergence among different implementations of Z39.50 clients and servers, due mainly to the large size/coverage of the Z39.50 Standard. One of the key issues in this Project will be to ensure optimum match among the Z39.50 Servers in tendered Configurations and the Z39.50 Client contained within the Gateway package, in order to maximise search functionality available to users.
The Library intends to provide access to the HTTP/Z39.50 Gateway via Web browser software commonly available to a wide variety of users, using a variety of desktop equipment, eg PCs, Macintosh, X-terminals and ASCII terminals, connected to the Internet through different mechanisms (see Figure 1.1). However, the user interface should be aimed at commonly used versions of graphical Web browsers, eg Microsoft Explorer and Netscape Navigator, rather than users with text only interfaces, eg Lynx.
In the present context, the HTTP/Z39.50 Gateway is also expected to perform a range of the functions of a modern versatile User Interface as described in detail in Section 4.3.3 below.
4.3.2 Mapping to Configurations
The capabilities sought in this section relate to Configurations #3.1, #3.2 and #3.3.
4.3.3 General Capabilities Sought
4.3.3.1 A single point of access from Web Browsers
a) The proposed HTTP/Z39.50 Gateway is to act as a single point of access for a user to all information resources accessible through the Library's Networked Services environment.
b) These resources would include the Library's own resources/services, ie the National Bibliographic Utility and (possibly) the Integrated Library Management System in stage 1, as well as external resources available via the Internet.
c) Access will be from Web browsers, and target resources are to include Z39.50 as well as HTTP servers.
d) For Z39.50 target servers, the Gateway will need to perform a conversion from a request from a form on a Web browser to query requests in Z39.50 protocol, prior to dispatching the query to a target Z39.50 server. Similarly, the Gateway will need to perform a reverse conversion of the result sets to HTML to send back to the browsers.
4.3.3.2 Version 3 and its Extended Services
The Library has a strong preference for a Version 3 implementation of the Z39.50 Client within the tendered Gateway package, because of its much enhanced scope over the Version 2 standard. This includes use of the Z39.50 Explain service to dynamically construct query interface screens and provide content knowledge of Z39.50 databases. In particular, the Library would like to have a range of Version 3 'Extended Services' features built into the Client, such as query saving.
4.3.3.3 Functionality of the proposed HTTP/Z39.50 Gateway
a) Establishing session control and history.
b) Provision for staff in Customer Libraries to define default profiles to control such features as managing a preferred set of target data resources.
c) Managing the searches against individual servers, or controlled 'broadcasting' of searches against multiple target resources, such that users perceive their search as being executed 'simultaneously' against such resources. Such management would include:
i. rapid sequential search submission
ii. handling of server response and non-response
iii. Gateway termination of pending searches in cases of non-response (time-out)
iv. organisation of search responses into a coherent display order
v. managing user inquiries for additional information or more detailed displays
vi. any required mapping of responses from target resources into a format consistent with the Library's standard User Interface and application framework
vii. an ability to conduct interlibrary loan requests, document delivery and downline loading operations under the control of the HTTP/Z39.50 Gateway, subject to any constraints on the source material. The Library prefers that the requesting mechanisms address both digital resources and analog (such as print material referred to in Library's catalogues) resources, with variations in detail processes as needed
viii. optionally, the provision for an Easy and an Advanced search mode to allow intuitive searching with appropriate Help facilities, and more complex and precise searching for professional search intermediaries, respectively.
4.3.4 Specific Capabilities Sought
No specific requirements are put forward for the HTTP/Z39.50 Gateway, as this is a relatively new and developing functional area. The Library is open to specific capabilities if the products meet a significant proportion of the general capabilities listed in Section 4.3.3.
4.3.5 Questions
a) Describe the scope of the HTTP/Z39.50 Gateway response, and provide a breakdown in alignment with the sections outlined in Section 4.3.3, if possible. If the Tendered System does not conform with the categories in Section 4.3.3, please state so explicitly, and describe how the Tendered System will contribute to the overall aim of the Gateway function as described in Section 4.3.1 and Section 4.3.3.
b) Where possible, describe the functions of the tendered Gateway components in terms of where these fit in the overall scenario, ie whether these functions belong to User entry management, capturing session history, providing Extended Services, etc.
c) Describe how all the linkages with various other Configurations (see Section 4.3.6 below) will work.
d) How will you ensure maximum coherence with the Z39.50 Server capabilities of the NBU and ILMS products, and future products selected by the Library for the later stages of this Project, both for initial implementation and for subsequent ongoing upgrades? Please describe the technical and the liaison process.
e) Z39.50 is a rapidly evolving standard, and large in scope. How committed is your company to maintaining a long term pro-active involvement in tracking and implementing new features/Versions ? How do you propose to conduct the decision making processes regarding the priorities, timing and content of such implementations? Please describe, and state any previous work in this area, any reference organisations, etc. Which services of Z39.50, Version 3 are supported?
f) Technical issues: please answer the generic questions in Section 5.10 as applicable to Configuration #3.
4.3.6 Links to Other Configurations
The HTTP/Z39.50 Gateway is required to link to the National Bibliographic Utility (Configuration #1) and (possibly) the Integrated Library Management System (Configuration #6). Tenderers should explain the relationships between these Configurations. Tenderers should refer to Section 1.8 and Figure 1.1 for the Library's proposed extensions to this Configuration. Tenderers are invited to comment on these extensions.
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Last updated 1 April 1997
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