XCON data modeling – NETCONF, RDF and others draft-schulzrinne-sipping-emergency-req-01 draft-sipping-sosExecutive summaryData representation models“Semantic” descriptionRDFRDF, cont’d.RDF/XML exampleMore about RDFRDF: evaluationNETCONFNETCONF, cont’d.Slide 12NETCONF RPCNETCONF – subtree filteringNETCONF operationsNETCONF capabilities advertisementUser-interface orientedSlide 18XForms exampleConclusionXCON - IETF 62 (March 2005) - Minneapolis1XCON data modeling – NETCONF, RDF and othersdraft-schulzrinne-sipping-emergency-req-01draft-sipping-sosHenning SchulzrinneDept. of Computer ScienceColumbia UniversityXCON - IETF 62 (March 2005) - Minneapolis2Executive summary•XCON is an instance of a standard problem  avoid the IETF tendency to create one-off protocols–excusable a decade ago, recipe for delay now•Provide both “semantic” (tightly constrained) and user interface-oriented interface•Use XForms where user interface is needed•Consider NETCONF for object content manipulation and state retrievalXCON - IETF 62 (March 2005) - Minneapolis3Data representation models•Document model–structured document•RPC model–set/get variables•Data models–RDF–NETCONF–user-interface orientedXCON - IETF 62 (March 2005) - Minneapolis4“Semantic” description•Tightly described set of properties•No expectation that user interface would directly correspond to each element•No I18N issue  application maps description elements to UI elements in appropriate language–translation into other languages done by client–and may derive some parts through local policy, rather than user input•Well-defined extension policyXCON - IETF 62 (March 2005) - Minneapolis5RDF•“Resource Description Framework (RDF) is a language for representing information about resources in the World Wide Web.”•describing resources in terms of simple properties and property valuesXCON - IETF 62 (March 2005) - Minneapolis6RDF, cont’d.W3C RDF primerXCON - IETF 62 (March 2005) - Minneapolis7RDF/XML example<?xml version="1.0"?><rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#“xmlns:contact="http://www.w3.org/2000/10/swap/pim/contact#"><contact:Person rdf:about="http://www.w3.org/People/EM/contact#me"><contact:fullName>Eric Miller</contact:fullName><contact:mailbox rdf:resource="mailto:[email protected]"/><contact:personalTitle>Dr.</contact:personalTitle></contact:Person></rdf:RDF> W3 RDF primeridentifies the thing = subject (a URI)property = predicatevalue = objectXCON - IETF 62 (March 2005) - Minneapolis8More about RDF•Generally, “meta data”•RSS is most common usage•Also used in Composite Capabilities/Preferences Profile (CC/PP)•Has schema-like capability to describe vocabularies•Allows trees with nodes and relationships (“is-a”, “has”)XCON - IETF 62 (March 2005) - Minneapolis9RDF: evaluation•Good–limited parameter-value expressiveness–type definition–tools available•Bad:–static document, does not define protocol to get/set elements–would need XCAP, XPath or similarXCON - IETF 62 (March 2005) - Minneapolis10NETCONF•“The NETCONF protocol defines a simple mechanism through which a network device can be managed, configuration data information can be retrieved, and new configuration data can be uploaded and manipulated. The protocol allows the device to expose a full, formal, application programming interface (API).”•http://www.ietf.org/internet-drafts/draft-ietf-netconf-prot-05.txt•Defined to run over HTTP, BEEP, UDP, …XCON - IETF 62 (March 2005) - Minneapolis11NETCONF, cont’d.contentoperationsRPCapplicationprotocolconfiguration data<get-config><edit-config><rpc><rpc-reply>BEEP, SSH, SSLXCON - IETF 62 (March 2005) - Minneapolis12NETCONF•Data =–configuration data = writable  <get-config>–state data = read-only, statistics  <get>•Leaves privacy and authentication to transport layer•Supports Xpath and subtree filtering•Supports multiple “data stores”–default <running>–<candidate> allows incremental update + commitXCON - IETF 62 (March 2005) - Minneapolis13NETCONF RPC<rpc message-id="101" xmlns="urn:ietf:params:xml:ns:netconf:base:1.0"><rock-the-house xmlns="http://example.net/rock/1.0"><zip-code>27606-0100</zip-code></rock-the-house></rpc><rpc-reply message-id="101" xmlns="urn:ietf:params:xml:ns:netconf:base:1.0"><some-content><!-- contents here... --></some-content></rpc-reply>XCON - IETF 62 (March 2005) - Minneapolis14NETCONF – subtree filtering<rpc message-id="101" xmlns="urn:ietf:params:xml:ns:netconf:base:1.0"><get-config><source><running/></source><filter type="subtree"><top xmlns="http://example.com/schema/1.2/config"><users/></top></filter></get-config></rpc>XCON - IETF 62 (March 2005) - Minneapolis15NETCONF operationsgetRetrieve all or part of state + configurationget-configRetrieve all or part of a specified configuration. edit-configmerge/create/replace/delete; with possible roll-backcopy-configcompletely replaces configurationdelete-configdelete a configuration datastorelocklock configuration data storeunlockunlock configuration data storeclose-sessiongraceful termination; releases lockskill-sessionabort connectionXCON - IETF 62 (March 2005) - Minneapolis16NETCONF capabilities advertisement<hello xmlns="urn:ietf:params:xml:ns:netconf:base:1.0"><capabilities><capability>urn:ietf:params:xml:ns:netconf:base:1.0</capability><capability>urn:ietf:params:xml:ns:netconf:base:1.0#startup</capability><capability>http:/example.net/router/2.3/core#myfeature</capability></capabilities><session-id>4</session-id></hello>XCON - IETF 62 (March 2005) - Minneapolis17User-interface oriented•Describe suggested rendering on controlling client without client knowing meaning of controls–element names are just labels–e.g., can’t gateway to other systems based on equivalence•user interface can change at any time•Element names are text strings, not XML elements–no schema verification possibleXCON - IETF 62 (March 2005) - Minneapolis18User-interface oriented•Client software does not need to understand meaning of terms – just variables and prompts–includes necessary prompts and structure–needs to be translated into different languages by server•Existing work: XForms–http://www.w3.org/MarkUp/Forms/2003/xforms-for-html-authors•Allows use of CSS to render on variety of devices•Allows use of JavaScript for client-side verification•Specifies type of control (“selection”), not