IETF69 BOF XSD for accessing SMIv2 data models

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IETF69 BOFXSD for accessing SMIv2 data models

• Yan Li
• liyan_77_at_huawei.com

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Outline

• Datatypes for Netconf Data Models
• Using Smidump to Convert MIB to XSD
• Accessing MIBs using NETCONF

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• Datatypes for Netconf Data Models
• Using Smidump to Convert MIB to XSD
• Accessing MIBs using NETCONF

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Background

• RFC 4181 Guidelines for Authors and Reviewers of
  MIB Documents lists an initial set of commonly
  used Textual Conventions. Their semantics and
  syntax could be reused by NETCONF and other
  XML-based management protocols

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Mapping of Datatypes and Textual Conventions
SMI / TC XSD
TruthValue Boolean
Enumerated INTEGER String (with an enumeration constrain)
Numeric Integer (Integer32, Counter, Gauge) Integer and its derivant (int, unsignedInt, long, unsignedLong)
Timeticks, TimeInterval, TimeStamp Duration
DateAndTime dateTime
String (OctetString, DisplayString) String and its derivant
Address (IpAddress, MacAddress, InetAddress) String (with a specific pattern)
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Mapping of Datatypes and Textual Conventions
(cont.)
SMI / TC XSD
BITS A list of enumerated string
OBJECT IDENTIFIER anyURI String representing an XPath expression
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Open Issues

• Is the EnabledStatus (P-BRIDGE-MIB) needed?
• SNMP-Specific TCs
• - TestAndIncr
• - RowStatus
• - StorageType

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Next Step

• Discuss case by case to identify which TCs are
  needed.

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• Datatypes for Netconf Data Models
• Using Smidump to Convert MIB to XSD
• Accessing MIBs using NETCONF

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Mapping of Datatypes Used by Smidump
SMI / TC XSD
Integer32 int
OctetString hexBinary (with restriction of length)
Unsigned32, Counter32, Gauge32 unsignedInt
Counter64 unsignedLong
Enumerated INTEGER NMTOKEN (with restriction of enumeration)
TimeTicks, TimeStamp unsignedInt
TimeInterval int
DateAndTime String (with a specific pattern)
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Mapping of Datatyes Used by Smidump (cont.)
SMI / TC XSD
OBJECT IDENTIFIER string (with restriction of length and pattern)
BITS A list of enumerated NMTOKEN (The list is restricted by maxLength)
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Structure of the XML Instance Documents invented
by Smidump

• Smidump invents a "flattened" structure of the
  XML instance documents

• ltsnmp-datagt
• --ltcontextgt
• --A container of scalar elements
  (one or more)
• --scalar objects
• --An instance of table entry (one
  or more)
• --columnar objects

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Example of IF-MIB

• ltsnmp-data xmlns"http//www.ibr.cs.tu-bs.de/proje
  cts/libsmi/xsd/IF-MIB"gt
• ltcontext ipaddr hostname port
  community timegt
• ltinterfacesgt
• ltifNumbergtlt/ifNumbergt
• lt/interfacesgt
• ltifMIBObjectsgt
• ltifTableLastChangegtlt/ifTableLastChang
  egt
• ltifStackLastChangegtlt/ifStackLastChang
  egt
• lt/ifMIBObjectsgt
• ltifEntry ifIndex"1"gt
• ltifTypegtlt/ifTypegt
• lt/ifEntrygt
• ltifXEntrygtlt/ifXEntrygt
• ltifStackEntrygtlt/ifStackEntrygt
• ltifTestEntrygtlt/ifTestEntrygt
• ltifRcvAddressEntrygtlt/ifRcvAddressEntrygt
• lt/contextgt
• lt/snmp-datagt

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The Output XSD of Smidump

• ltxsdelement name"ifDescr" minOccurs"0"gt
• ltxsdannotationgt
• ltxsdappinfogt
• ltmaxAccessgtread-onlylt/maxAccessgt
• ltoidgt1.3.6.1.2.1.2.2.1.2lt/oidgt
• ltstatusgtcurrentlt/statusgt
• lt/xsdappinfogt
• ltxsddocumentationgtlt/xsddocumentationgt
• lt/xsdannotationgt
• ltxsdsimpleTypegt
• ltxsdannotationgt
• ltxsdappinfogt
• ltdisplayHintgt255alt/displayHintgt
• lt/xsdappinfogt
• lt/xsdannotationgt
• ltxsdrestriction base"xsdstring"gt
• ltxsdpattern value"((((\pIsBasicLati
  n))0,255))0,1"/gt
• lt/xsdrestrictiongt
• lt/xsdsimpleTypegt

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• Datatypes for Netconf Data Models
• Using Smidump to Convert MIB to XSD
• Accessing MIBs using NETCONF

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Motivation

• There is no data model for NETCONF, even a data
  modeling language at this time. But operators
  expect device vendors support NETCONF right now.
  What data models should device vendors provide?
• The proprietary data models impair
  interoperability between devices and applications
  from different vendors. Actually it is another
  version of CLI.
• The standard data models for NETCONF are destined
  to replace the proprietary data models in the
  near future. So device vendors will gain little
  return from developing proprietary data models
• There is a need for standard data models for
  transiting toward NETCONF, the SMI MIB is an
  alternative
• - SMI MIB is widely used for a long time,
  there are over 200 standard MIB modules
• -There is an open source tool, libsmi,
  which can convert SMI MIB into XSD conveniently
• A standard approach for accessing MIB may be used
  by not only NETCONF, but other XML-based NM
  protocols as well.

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Approach for Accessing MIB

• Use the XSD converted by smidump as data model
• Add a capability for NETCONF
• The capability contains two SNMP-specific
  operations
• - ltmib-getgt, has a optional
  max-repetitions attribute for retrieving table
  entries.
• - ltmib-setgt, has a optional operation
  attribute for creating or deleting a table entry.

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Example of ltmib-getgt

• ltrpc message-id"101"
• xmlns"urnietfparamsxmlnsnetconfbase1
  .0"
• xmlnsmib"urnietfparamsxmlnsnetconfmi
  b1.0"gt
• ltmibmib-getgt
• ltfilter type"subtree"gt
• ltsnmp-data
• xmlns"http//www.ibr.cs.tu-bs.de/projec
  ts/libsmi/xsd/IF-MIB"gt
• ltcontext ipaddr"192.0.2.1" port"830"
• community"public"
  time"2006-12-05T080808Z"gt
• ltifEntry ifIndex"1"gt
• ltifType/gt
• ltifMtu/gt
• lt/ifEntrygt
• lt/contextgt
• lt/snmp-datagt
• lt/filtergt
• lt/mibmib-getgt
• lt/rpcgt

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Example of ltmib-setgt

• ltrpc message-id"101"
• xmlns"urnietfparamsxmlnsnetconfbase
  1.0"
• xmlnsmib"urnietfparamsxmlnsnetconf
  mib1.0"gt
• ltmibmib-setgt
• ltsnmp-data
• xmlns"http//www.ibr.cs.tu-bs.de/projec
  ts/libsmi/xsd/IF-MIB"gt
• ltcontext ipaddr"192.0.2.1" port"830"
• community"public"
  time"2006-12-05T080808Z"gt
• ltifStackEntry ifStackHigherLayer"1"
  ifStackLowerLayer"2"
• miboperation"create"/gt
  
• lt/contextgt
• lt/snmp-datagt
• lt/mibmib-setgt
• lt/rpcgt

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Open Issues

• ltmib-getgt vs. ltgetgt
• Should the max-repetitions attribute be
  inherited from SNMP?
• Is the set functionality needed?

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Thank You

• Questions?

• Contact info
• Yan Li liyan_77_at_huawei.com