Complex Types and Typed Instance Identifiers

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Complex Types and Typed Instance Identifiers

• IETF 76
• NETMOD WG
• bernd.linowski.ext_at_nsn.com
• mehmet.ersue_at_nsn.com

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Changes since IETF 75

• Complex types as YANG extensions
• Modified complex type syntax
• Renamed element(-list) to instance-(list)
• New extension keyword instance-type
• Update rules for complex types added
• Complex type feature added
• IANA considerations addressed

-gt Semantics of complex types unchanged!
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Complex Types and Typed Instance Identifiers
Specified in form of a YANG module
module complex-types //
prefix "ct" // extension
complex-type description "Defines a
complex-type." reference "chapter
2.2., complex-type extension statement"
argument type-identifier
yin-element true
extension extends description
"Defines the base type of a complex-type."
reference "chapter 2.5., extends extension
statement" argument
base-type-identifier
yin-element true
// . feature complex-types
description "This feature indicates that the
agent supports complex
types and instance identifiers."
Extension definitions
Feature indicating complex type support
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Further steps

• pyang plug-ins
• complex type validation (under construction)
• mapping to XSD and RelaxNG (planned)
• Anything to add to the draft?
• We welcome any comments
• Is anybody interested to co-author?
• How should we proceed?
• Proposed standard or Experimental?

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Thank You! Question?
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Support for High-Level abstractions
TMF SID

• Complex types
• Blueprint for instances

ctcomplex-type Equipment ctextends
PyhsicalContainer ctabstract true leaf
installStatus ctinstance-list equipment
type Equipment ctcomplex-type Card
ctextends Equipment

• Complex type instances
• single
• list

Complex types Extensions
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Recursive Structures in Model and Payload
Complex type nesting
ctcomplex-type EquipmentHolder ctextends
ManagedHardware ctabstract true ctinstance-l
ist equipment type Equipment
ctinstance-list holder type
EquipmentHolder
Recursive containment with unknown depth
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Recursive Structures in Model and Payload
ltholdergt ltobjectIdgtRack-A2lt/objectIdgt ltholder
gt ltobjectIdgtSubrack-1lt/objectIdgt ltequipmen
tgt ltobjectIdgtCard-1lt/objectIdgt lt/equipm
entgt ltholdergt ltobjectIdgtBackplane-Alt/objectId
gt ltequipmentgt ltobjectIdgtCard-1lt/object
Idgt lt/equipmentgt lt/holdergt lt/holdergt lt
/holdergt ltholdergt // more holders lt/holdergt
NETCONF payload reflects instance nesting
Simple filter to select sub-tree under a
particular tree node
ltfilter type"subtree"gt lttop xmlns"http//examp
le.com/hw"gt ltholdergt ltobjectIdgtRack-A2lt/obj
ectIdgt lt/holdergt lt/topgt lt/filtergt
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Base Type Substitution
ctcomplex-type PhysicalPort
ctabstract true key portNumber
leaf portNumber type int32
mandatory true ctcomplex-type Card
ctinstance-list port type
PhysicalPort ctcomplex-type
PluginModule ctinstance-list port type
PhysicalPort
Derived complex-type
ctcomplex-type ExtPhysicalPort
ctextends PhysicalPort

• Substitution of base type instance with derived
  type instances
• wherever the base type is used
• no need to know all places it is used

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Rich Type Definitions

• Definition of abstract types
• enforce common attributes
• must be extended to be instantiated

ctcomplex-type PhysicalPort ctabstract
true key portNumber leaf portNumber type
int32 mandatory true ctcomplex-type Card
ctinstance-list port type
PhysicalPort ctcomplex-type PluginModule
ctinstance-list port type
PhysicalPort

• Definition of types with a key
• no need to add key definitions at every place of
  use

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Type Information In Payload
ltholdergt ltobjectIdgtR31s2lt/objectIdgt ltcttypegthw
Slotlt/cttypegt ltslotNumbergt1lt/slotNumbergt ltymit
ypegthwEquipmentHolderlt/ymitypegt ltequipmentgt lt
objectIdgtATM-45252lt/objectIdgt ltcttypegthwSTMCar
dlt/cttypegt ltlevelgt16lt/levelgt ltcttypegthwCard
lt/cttypegt ltusedSlotsgt1lt/usedSlotsgt ltinstalled
gttruelt/installedgt ltversiongtA2lt/versiongt ltredun
dancygt1lt/redundancygt ltserialNumbergtA-778911-blt/s
erialNumbergt ltcommonNamegtATM-ADM
2lt/commonNamegt lt/equipmentgt ltserialNumbergtT-K473
3890x45lt/serialNumbergt ltcommonNamegtCU-Slotlt/commo
nNamegt lt/holdergt

• Use of predefined set of properties controlled by
  a type

• Type information in the payload
• Enables handling of unknown derived types
• Does not require explicit type codes
• Filtering types including derived types

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Instance Identifiers Restricted by Type
ctcomplex-type PhysicalPort
ctextends ManagedHardware leaf
portNumber type int32 mandatory true
ctcomplex-type PhysicalLink ctextends
ManagedHardware leaf-list connectedPort
type instance-identifier ctinstance-type
PhysicalPort min-elements 2
Constrains what type of entity may be identified

• Allows to refer to instances of
• referred type
• derived types added later