Network Working Group S.E. Kille INTERNET--DRAFT University College London March 1991 Handling QOS (Quality of service) in the Directory Status of this Memo This document describes a mechanism for specifying the Quality of Service for DSA Operations and Data in the Internet Pilot Directory Service [Kil90]. This draft document will be submitted to the RFC editor as a protocol specification. Distribution of this memo is unlimited. Please send comments to the author or to the discussion group . INTERNET--DRAFT QOS in the Directory March 1991 1 Introduction There have been a lot of problems with the variable quality of data and service over the directory. These attributes are proposed for use in the overall pilot (not implementation specific). In order that these attributes may be useful, it will be necessary to ensure that they are used throughout the pilot. For this reason, this specification is being made into a protocol standard. The usage of these attributes will be registered in the Cosine and Internet X.500 Sechema [BK91]. The QOS definitions can be used in the following ways: 1. By a user as additional information 2. By a system manager to determine what course of action to take following operational problems 3. By a DSA, as a heuristic to improve distributed operation (DSA choice) 4. By a DUA, perhaps to hide experimental stuff, or to indicate the quality of data/service to the user Parameters are given encoded values to facilitate automatic processing, and string values as it is recognised that useful subtleties of service can be indicated which are useful to the end user (e.g., as to which aspects of the data can be trusted) 2 DSA Controls The following attributes should be mandatory in the entry in the DIT which represents each pilot DSA. When information in the DIT is of high quality, it should be stored in DSAs of an appropriate service level. DSAQuality ATTRIBUTE WITH ATTRIBUTE-SYNTAX DSAQualitySyntax SINGLE VALUE DSAQualitySyntax ::= SEQUENCE - serviceQuality ENUMERATED - defunct(0), -- not present Kille Page 1 INTERNET--DRAFT QOS in the Directory March 1991 experimental (1), -- unlikely to be present best-effort (2), -- no guaranteed support pilot-service (3), -- aim for >90% availability full-service (4) -- expect >95% availability -- ", description PrintableString OPTIONAL " 3 DIT Controls The following attributes are defined, and should be present in every non-leaf entry in the DIT. If it is not present, the value of the attributes in the parent entry are assumed. QualityLabelledData OBJECT-CLASS SUBCLASS OF top MUST CONTAIN -SingleLevelQuality" MAY CONTAIN -SubtreeMinimumQuality, SubtreeMaximumQuality" SingleLevelQuality ATTRIBUTE WITH ATTRIBUTE-SYNTAX DataQualitySyntax SINGLE VALUE -- Note that Subtree quality excludes the entries at the first level -- It summarises the quality attributes at the levels below SubtreeMaximumQuality ATTRIBUTE WITH ATTRIBUTE-SYNTAX DataQualitySyntax SINGLE VALUE -- Defaults to SingleLevelQuality SubtreeMinimumQuality ATTRIBUTE WITH ATTRIBUTE-SYNTAX DataQualitySyntax SINGLE VALUE -- Defaults to SingleLevelQuality DataQualitySyntax ::= SEQUENCE - namespace-completeness Completeness, defaultAttributeQuality AttributeQuality, attributeQuality SET OF SEQUENCE - AttributeType, AttributeQuality ", Kille Page 2 INTERNET--DRAFT QOS in the Directory March 1991 description PrintableString OPTIONAL " Completeness ::= ENUMERATED - none(1), sample(2), -- small number present at random selected(3), -- partial coverage with most significant -- values present substantial(4), -- >80% coverage full(5) -- all values present ", AttributeQuality ::= SEQUENCE - maintenance-level ENUMERATED - unknown(1), -- may be suspect external(2), -- downloaded from external source -- of variable quality system-maintained(3), -- if there is a value, it will -- be present and reasonably -- accurate user-supplied(4) " attribute-completeness DEFAULT full " The SingleLevelQuality attribute refers to the entries one level below. Where there are further levels, the other two attributes give an indication of the spectrum of quality of data in the lower levels. The quality of the data indicates both its coverage (of the entries named), and the quality of attributes within the entries. Note: It might be appropriate to measure data quality on the basis of object classes at the level below. Comments are solicited about this increase in complexity. References [BK91] P. Barker and S.E. Kille. The COSINE and Internet X.500 Kille Page 3 INTERNET--DRAFT QOS in the Directory March 1991 schema, March 1991. Internet Draft: draft-ietf-osids-cosinex500-02.txt. [Kil90] S.E. Kille. Building and internet directory using X.500, November 1990. Internet Draft: draft-ietf-osix500-directories-01.txt. 4 Security Considerations Security considerations are not discussed in this INTERNET--DRAFT . 5 Author's Address Steve Kille Department of Computer Science University College London Gower Street WC1E 6BT England Phone: +44-71-380-7294 EMail: S.Kille@CS.UCL.AC.UK Kille Page 4