Proposal To Extend the X.500 Directory User Agent Project Andrew Findlay Damanjit Mahl Stefan Nahajski Brunel University X500@uk.ac.brunel 29 June 1990 1. Background In 1989, the Computer Board issued a contract to Brunel University for the development of User Interfaces for the X.500 Directory. Work started in September 1989, and several working prototypes have been released to the commun- ity for comment. Feedback from the community has been taken into account, and an interface design produced. This design is rather more ambitious than the one described in the original proposal. Is is therefore proposed that the development contract should be modified and extended to allow the design to be fully implemented. 2. New work items 2.1. DSAP implementation for PC The original proposal assumed that an ISODE-like implementa- tion of DSAP would be provided for the PC. Since the JNT's PC-comms Group has now decided to buy in and modify a com- mercial ISO stack for the PC, it will be necessary to imple- ment a new DSAP library to interface with it. This item also covers the extra work that will be required to make use of other services (like ASN.1 conversion) where the inter- face will not be ISODE-like. Deliverable: DSAP library for PC, programmers guide. 2.2. Conversion of existing design to use asynchronous interface to DSAP The existing DUA design assumes a DSAP interface as speci- fied in ISODE 6.0 which is purely synchronous. There are advantages to using an asynchronous interface. This item covers the conversion effort. 2.3. Extra work required due to more ambitious and flexible design The original proposal was written on the assumption that the final product would have functionality approximately the same as Pod. During the development of the design, it has become apparent that users (or system managers at least!) require more flexibility. The design document for Xdir reflects this. In particular, the design now calls for much greater control of appearance and function by configuration files. Providing this flexibility and the configuration tools to use it easily will require significant effort beyond that originally estimated. Deliverables: Advanced user interfaces for Unix and DOS 2.4. Character-based interface for Unix machines In the early stages of the project, a character-based inter- face was produced for experimental purposes and to encourage user feedback. It was not intended that this interface would be supported once the X and PC interfaces were avail- able. Taking account of comments from the community, it now appears that there will be a substantial demand for character-based interfaces for some years yet. It is there- fore proposed that sd should be re-implemented on top of the new query engine, and using some of the configuration files applicable to Xdir. This interface will provide as many of the functions of Xdir as possible on a character screen, but it will not be confi- gurable to the same extent as the X-based interface. Deliverables: Character based interface. 2.5. Special implementation for low-end PCs The PC-comms group has defined two PC scenarios. One is a `high-end' PC running a full ISO stack and several Windows applications simultaneously. The other is a `low-end' PC which can manage only one small application at a time. MS- Windows will not be used, so the programming environment is rather different. This work item covers the production of a cut-down version of the PC DUA that will run on these smaller machines. Some of the functions and flexibility of the full interface will inevitably be lost, but the inter- face should still be useful for most day-to-day tasks. The application will make use of a mouse where this is avail- able, but will not require one. Deliverables: Interface that will run on a `low-end' PC. 2.6. Motif implementation It is proposed that the first implementation of Xdir for X will use the Athena widget set. This allows the interface to be used by any site that has X, as the Athena widgets are part of the standard distribution. Some sites may begin using Motif in the future, depending on licence requirements and cost. This work item covers the production of a Motif- based version of Xdir which can be used by those sites with Motif licences. Deliverables: Motif version of Xdir 3. Modification of existing contract Several of the work items described above affect the exist- ing work, so it is proposed that: An enhanced version of the Pod interface will be delivered and invoiced as the `Unix interface' for stage 5. Delivery of the `PC interface' for stage 5 will be delayed until a working prototype can be produced, rather than delivering a non-functioning interface with no ISO stack. After a short period of evaluation in the community, this interface will be delivered and invoiced for. Work will start immediately on implementation of the full design.