1、7/13/98,WISEN - Internet Printing Events and Notification,1,Internet Printing Events and Notification,Scott Isaacson () Corporate Architect, Novell Inc. Principal Editor, IETF IPP,7/13/98,WISEN - Internet Printing Events and Notification,2,Agenda,Background and Context Requirements and Solutions Con
2、clusions and Recommendations,7/13/98,WISEN - Internet Printing Events and Notification,3,Printer Working Group (PWG),PWG is a loose coalition of companies interested in network printing products and systems http:/www.pwg.org Printer Management SNMP Alerts: Printer MIB, Job Monitoring MIB Sense IEEE
3、1284.1 (aka TIPSI, aka NPAP) Solid experience base for Printer and Printing related events and event semantics e.g: “online” and “offline”,7/13/98,WISEN - Internet Printing Events and Notification,4,Internet Printing Protocol (IPP) IETF Working Group,Internet Printing Protocol (IPP) Internet-Drafts
4、http:/www.ietf.org/internet-drafts/draft-ietf-ipp-model-10.txt http:/www.ietf.org/internet-drafts/draft-ietf-ipp-protocol-06.txt http:/www.ietf.org/internet-drafts/draft-ietf-ipp-not-01.txt IPP/1.0 Query only (no event push semantics) Extensible (new attributes, new operations) Working Group next st
5、eps (soon to be Internet-Drafts)ftp:/ftp.pwg.org/pub/pwg/ipp/new_NOT/ ipp-notifications-very-short-980701.pdf ipp-notification-printer-980701.pdf,7/13/98,WISEN - Internet Printing Events and Notification,5,Industry “Standards” Survey,OMG Event Service Notification Service The Open Group Java Message
6、 Service (JMS) Topics and Queues SNMPv3 Traps and Informs Event MIB Notification MIB,7/13/98,WISEN - Internet Printing Events and Notification,6,No Channel Abstraction,7/13/98,WISEN - Internet Printing Events and Notification,7,Scalability: Channel Abstraction,Channel,7/13/98,WISEN - Internet Printi
7、ng Events and Notification,8,Communities of Interest: Multiple Channels,7/13/98,WISEN - Internet Printing Events and Notification,9,Very Large Numbers of Clients,7/13/98,WISEN - Internet Printing Events and Notification,10,Findings: Common Themes,Event Consumer(s) and Event Producer(s) Intermediary
8、“channel” abstraction Queues, Topics, Items, Events, Push, Pull QoS privacy, authentication, authorization, latency Variants durable, once, at-least-once, at-most-once, maybe Event subsystem is not unique to Printing No need to invent a print-specific mechanism Only events semantics, groupings, and
9、optimizations are unique,7/13/98,WISEN - Internet Printing Events and Notification,11,Printing and Event Notification,Event Consumer(s) Humans, programs, databases Event Producer(s) IPP objects: “Printer” and “Print Job” Multiple notification methods e-mail programmatic log file etc.,7/13/98,WISEN -
10、 Internet Printing Events and Notification,12,Printing and Event Notification (cont.),Multiple Human Roles Job Recipient Job Recipient Proxy Notification Recipient Notification Recipient Agent Events Groups Job vs Device Errors, Warnings, or Reports Frequency (“Job Complete” vs “Page 3 Complete”),7/
11、13/98,WISEN - Internet Printing Events and Notification,13,Printing and Event Notification (cont.),Event Report Fully describes the event (what the event was, where it occurred, when it occurred, etc.) Human Consumable Machine Consumable Mixed Format Types of Notification (tied to delivery method?)
12、Immediate Notification Queued Notification,7/13/98,WISEN - Internet Printing Events and Notification,14,Notification Architecture without an Event Service,Print Request,Report,Event Producer,Job Submitting End User,Notification Recipient,Agent,7/13/98,WISEN - Internet Printing Events and Notificatio
13、n,15,Notification Architecture with an Event Service,Registration / Query,Print Request,Report,Persistent Requests,Event Producer,Job Submitting End User,Notification Recipient,Configuration Data,Agent,Separate Subscription,Report,Query,7/13/98,WISEN - Internet Printing Events and Notification,16,IP
14、P Notification Scenario,7/13/98,WISEN - Internet Printing Events and Notification,17,Printer Finds a Channel,Admin configuration option Name, address Browse a directory - LDAP Directory object for the channel Service Location Protocol (SLP) Registered “notification service”,7/13/98,WISEN - Internet
15、Printing Events and Notification,18,Submitting a Subscription,Subscription with Job Policy: OK if end-user is allowed to print Job and Printer events Job events: Only this Job Printer events: Only while this Job is active Profile outside of Job Policy: OK if “operator” Job and Printer events Job Eve
16、nts: All jobs Printer Events: Any/All printer event,7/13/98,WISEN - Internet Printing Events and Notification,19,I18N,Client requests a “language” and “charset” Report Contains Identifiers (not localized) Strings (localized) In client preference, if possible In Printer default, otherwise Assume: Cli
17、ent has access to a “identifier to localized string” database/cache,7/13/98,WISEN - Internet Printing Events and Notification,20,Report Content: Format,application/ipp machine consumable content using the application/ipp MIME media type text/plain human consumable content type Others: XML Format dep
18、endent on delivery method?,7/13/98,WISEN - Internet Printing Events and Notification,21,Subscription Options,Subscribe by groups or events? All Printer events All Printer Error events Specific Printer Error events Subscribe to multiple methods? These events via email Those events via beeper Ask for
19、more info? When the event happens, tell me this other things,7/13/98,WISEN - Internet Printing Events and Notification,22,Current Issues / Discussion Items,Is there the difference in functionality between end-user to IPP Printer (job complete) printer server to device (flow control) What are the “st
20、andard” delivery methods email - SMTP log file - FTP, HTTP programmatic - ? Others - ? What are the methods that MUST be supported?,7/13/98,WISEN - Internet Printing Events and Notification,23,Conclusions and Recommendations,Do not invent a print-specific event subsystem Subscribe via the Printer Pr
21、int clients already interact with the Printer No need to find a separate Topic or Message Queue Subscription is sent along with the print request Support Internationalization/Localization Support for additional attributes data Allow for multiple delivery methods Standardize on Printer MIB, Job MIB, and IPP defined events and semantics,
