2003-02-19SC25/WG1/N1028, Presentation on DCTP, ©2003 Farance Inc.1 Presentation to SC25/WG1 On DCTP Status Presentation By Frank Farance, Farance Inc.

2003-02-19 SC25/WG1/N1028, Presentation on DCTP, ©2003 Farance Inc. 1

Presentation to SC25/WG1 OnDCTP Status

Presentation By Frank Farance, Farance Inc.+1 212 486 4700, [email protected]


Rationale For DCTP

• Multiple vendors, incompatible solutions• No vendor will become the final standard• Compatibility is done via interoperability

protocols (also known as a “gateway”)• Vendors build “half-bridges” for interoperability• DCTP only addresses “transport”

– Other interoperability layered on top, e.g., lexicon


Background Information on 15067-1

• Data and Control Transfer Protocol (DCTP)• Based on work by Simon Garrett and other

contributions• Concerns interoperability (roughly layer 5)• ISO OSI stack is not implied, e.g., RS-232

transport is possible


What DCTP Does

• Common method for get/put values– Both numeric and non-numeric values

• Common method for passing params/control• Common framework for security (“plug-ins”)• Various connection frameworks

– connection vs. connectionless– point-to-point vs. broadcast– connected vs. roaming vs. sometimes-connected– bus vs. ring vs. point-to-point connectivity– depends upon underlying communications

• Very simple implementation paradigm– Supports low-memory, embedded systems– Data and control paradigms


What DCTP Does Not Do

• DCTP does not determine lexicon, e.g.,– Names of parameters– Acceptable values

• DCTP does not define naming of objects• DCTP does not require specific security services• DCTP does not specify transport facilities• DCTP does not mandate proprietary systems

change — gateways/virtualization is possible


Applications of DCTP

• Command and control (C2) for appliances/devices– Set/retrieve values– May be used for smart/dumb devices

• Bridging protocol/services among proprietary protocols/services

• DCTP can be “lower” level protocol support for higher APIs


How the Pieces Fit Together

Device/Ctrl #1

Device/Ctrl #2

Process:18012-4

Coding:18012-2 (lexicon)

ConformsTo “Registry”

Command/Control

e.g.,15067-1DCTP

Process: Determines what is entered in registry

Registry: Valid code sets; extension mechanism

Command/Control Protocol: Protocol binding of 18012-1, using 18012-2 codesets (lexicon), as maintained by 18012-4 process

Use ISO/IEC 11179-3 Metadata Registry for description

Applications: Claim conformance to: 18012-2, 15067-1

Creates/Administers

Consensus-BuildingProcess

Registry(table)


Portions of ISO/IEC 11179-3 Metamodel [1/7]

Data_Element_Concept

Conceptual_Domain

represent ing 0..*

represented_by 1..1

conceptual_domain_representat ion

represent ing

0..*

represented_by

1..1

data_el ement_representat ion

specifying

1..1

having

0..*

data_el ement_concept_conceptual_dom ain_rel ationship

expressing

0..*

expressed_by 1..1

data_el ement_concept_expression

Data_Element

Value_Domain


Derivat ion_Rulederivation_rule_administration_record[1..1] : Administrat ion_Recordderivation_rule_specification [1. .1] : String

Data_Element_Exampledata_element_example_item [1..n] : String

Data_Element_Derivation

1..1

0..*

applied_to

applying

derivation_rule_application

Value_Domainvalue_domain_administration_record [1..1] : Administrat ion_Recordvalue_domain_datatype [1. .1] : Datatypevalue_domain_unit_of_measure [0..1] : Unit_of_Measurevalue_domain_maximum_character_quantit y [0..1] : Integervalue_domain_format [0..1] : St ring

Data_Element̀data_element_administ ration_record [1. .1] : Administration_Recordrepresentation_class_qualifier [0..1] : Stringdata_element_precision [0. .1] : Integer

1..*exemplified_by

exemplifying0..*

exemplification

0..*

1..*

inputing

input_to

derivation_input

1..*

deriving0..1

derived_from

derivation_output

0..* 1..1represent ingrepresented_by

data_element_representation

Conceptual_Domain

conceptual_domain_administ ration_record [1. .1] : Administration_Recorddimensionality [0. .1] : String

0..*represent ing

represented_by 1..1

conceptual_domain_

representation

Data_Element_Conceptdata_element_concept_administ ration_record [1..1] : Administrat ion_Recorddata_element_concept_object_class [0..1] : Object_Classobject_class_qualifier [0. .1] : Stringdata_element_concept_property [0..1] : Propertyproperty_qualif ier [0..1] : St ring

0..*expressing

expressed_by1..1

data_element_concept_expression

0..*

specifying

1..1

having

data_element_concept_conceptual_domain_relationship

Enumerated_Value_Domain

Valuevalue_item [1..1] : String

Permissible_Valuepermissible_value_begin_date [1. .1] : Datepermissible_value_end_date [0..1] : Date

0..*

2..*

containing

contained_in

permissible_value_set

used_in1..1

has0..*

permitted_value

Value_Meaningvalue_meaning_ident ifier [1. .1] : Stringvalue_meaning_description [0. .1] : Stringvalue_meaning_begin_date [1..1] : Datevalue_meaning_end_date [0. .1] : Dateused_in 1..1

has 0..*

permissible_value_

meaning

Enumerated_Conceptual_Domain

1..*contained_in

containing 1..*

value_meaning_set

Non_enumerated_Value_Domainnon_enumerated_domain_description [1..1] : St ring

Non_enumerated_Conceptual_Domainnon_enumerated_conceptual_domain_description [1..1] : String

0..*

1..1

represent ing

+represented_by

non-enumerated_conceptual_domain_

representation



Property

property_administ rat ion_record [1. .1] : Adm inist ration_Record

Object_Class object_class_administration_record [1..1] : Administ rat ion_Record

concept_relati onship

Concept_Relationshipconcept_relati onship_type_description [1..1] : St ring

Concept 0.. *

0.. * using

Concept used_in

using

Conceptual_Domain

specifying

having 0.. *

Conceptual_Domain Conceptual_Domain

1.. 1

having

data_element_concept_conceptual_domai n_relat ionship


data_element_concept_object_class [0..1] : Obj ect_Class

object_class_qual ifier [0..1] : St ring data_element_concept_property [0. .1] : Property

property_qualif ier [0. .1] : St ring

data_element_concept _adm inist ration_record [1..1] : Administrati on_Record

Data_Element_Concept_Relationshipdata_element_concept_relationship_type_descript ion [1..1] : S tring

0.. *

0.. *

related to

related to data_element_concept_relationship



Dat aty pe

da tatype _na me [1 ..1] : St ringda tatype _de scriptio n [0.. 1] : Strin gda tatype _sche me_ refe ren ce [1. .1] : Str in gda tatype _an nota tion [0 ..1] : Str ing

Conceptual_Domain

con ceptu al_do main _ad ministr ation _reco rd [1..1] : Administ ratio n_Reco rddim ension ality [0 ..1] : Str ing

Value_Doma in

valu e_do main _ad ministr ation_ reco rd [1..1] : Administ ratio n_Reco rdvalu e_do main _da tatype [1..1 ] : Data type

valu e_do main _un it _of_ mea sure [0..1] : Unit_ of_M easu revalu e_do main _ma ximum _cha racte r_q uant ity [0..1 ] : Int egervalu e_do main _for mat [0..1] : String

1..1

re pre sentin g0..n

re pre sente d_by1..1

con ceptu al_do main _re pre senta tion

Repre sentat ion_Clas s

re pre senta tion_ cla ss_ad ministr ation _re cord [1..1 ] : Admin istrat io n_Re cord

0..*

0..1

type d_b y

typin g

valu e_do main _re pre senta tion_cla ss

Enume rat ed_Value _Domai n

Value

valu e_item [1.. 1] : Strin g

Permis sib le_Value

pe rmissib le_valu e_b egin_ date [1..1 ] : Datepe rmissib le_valu e_e nd_d ate [ 0..1] : Date

2..*

con taining 0..*

con taine d_in

pe rmissib le_valu e_se t

use d_in1..1

ha s0..*

pe rmitte d_va lue

Enume rat ed_Conceptual_Doma in

Value_M eaning

valu e_m eanin g_ide ntifier [1..1 ] : Strin gvalu e_m eanin g_d escript ion [0 ..1] : Str ingvalu e_m eanin g_b egin_ date [1..1 ] : Datevalu e_m eanin g_e nd_d ate [ 0..1] : Date

1..1use d_in

ha s 0..*

pe rmissib le_valu e_m ean in g

con taining1..*

con taine d_in1..*

valu e_m eanin g_se t

Non_enumerat ed_ Va lue _Domain

no n_en ume rate d_d oma in_de script io n [1 ..1] : Str ing

Non_enumerat ed_ Conceptua l_Domai n

no n_en ume rate d_co ncep tual_ dom ain_d escrip tion [1 ..1] : Str ing

0..*

1..1

re pre sentin g

re pre sente d_by

no n-e num erat ed_con ceptu al_do main _re pre senta tion

Uni t_of_M eas ure

un it_of_ mea sure _nam e [1 ..1] : Str ingun it_of_ mea sure _pr ecision [ 1..1] : Inte ger

Conceptual_Domain_ Relat ionshi p

con ceptu al_do main _re lationsh ip_typ e_d escrip tion [1 ..1] : Str ing

re lated to

re lated to0..*

0..*

con ceptu al_do main _re lationsh ip

Value_Doma in_Re lati ons hip

valu e_do main _re lationsh ip_typ e_d escrip tion [1 ..1] : Str ing

0..*

0..*

re lated to

re lated to valu e_do main _re lations hip



Conc eptual_Domain

concep tual_dom ain_admin istr ation_r ecord [1 ..1] : Administration _Recorddimen sio nality [0..1] : String

1..1rep resente d_by

1..1

concep tual_dom ain_rep resenta tio n

Value

value_ite m [1..1] : String

Permissibl e_Va lue

per missib le_value_b egin_date [1..1] : Dateper missib le_value_e nd_date [0..1] : Date

used_ in1..1

has0..*

per mitted_value

Enumera ted_ Conceptual_ Domain

Value_M eanin g

value_m eaning_ id entifier [1 ..1] : Stringvalue_m eaning_ description [0 ..1] : Stringvalue_m eaning_ begin_d ate [1..1] : Da tevalue_m eaning_ end_da te [0..1] : Da te

1..1used_ in

has 0..*

per missib le_value_m eaning

contain in g1..*

contain ed_in1..*

value_m eaning_ set

Non_ enumerated_Conce ptua l_Doma in

non _enume rated_ conceptual_ domain_d escription [1 ..1] : String

1..1rep resente d_by

non -enum erated _concep tual_dom ain_rep resenta tio n

Conc eptual_Domain_Rela tionship

concep tual_dom ain_relatio nship_type_d escription [1 ..1] : String

rela ted to

rela ted to0..*

0..*

concep tual_dom ain_relatio nship



Dat atyp e

da tatype_ nam e [1..1 ] : Stringda tatype_ descr iption [0 ..1] : Str ingda tatype_ schem e_re fere nce [1 ..1] : Str in gda tatype_ ann otation [0..1 ] : String

Value _Domain

value _dom ain_ admin is tration _re cord [1..1] : Ad ministra tion_ Re cordvalue _dom ain_ datatyp e [1. .1] : Dat atypevalue _dom ain_ unit_o f_me asure [0..1 ] : Unit_o f_Me asurevalue _dom ain_ maximu m_ch aract er_q uantity [0..1] : Integ ervalue _dom ain_ form at [0.. 1] : String

re prese nting0..n

con ceptua l_dom ain_re prese ntatio n

Repres ent ation_ Cl ass

re prese ntatio n_class_ admin istratio n_re cord [1..1] : Ad ministr ation_ Record

0..*

0..1

type d_by

typin g

value _dom ain_ repr esen tation_ class

Enumerat ed_ Val ue_Doma in

Permiss ible _Value

pe rmissible _value_ beg in _dat e [1..1 ] : Datepe rmissible _value_ end _date [0..1 ] : Date

2..*

con taining 0..*

con tained _in

pe rmissible _value_ set

ha s0..*ha s 0..*

Non_en umerated_Value_Domain

no n_en umer ated _dom ain_d escrip tion [1. .1] : Strin g

0..*re prese nting

Unit _of _Me asure

un it _of_m easu re_n ame [1..1] : Str ingun it _of_m easu re_p recision [1..1] : Inte ger

Value _Domain_Relat ionshi p

value _dom ain_ relatio nship_ type_d escript io n [1. .1] : Strin g

0..*

0..*

re lated t o

re lated t ovalue _dom ain_

re lationsh ip



Derivation_Rule

derivation_rule_administration_record[1..1] : Administration_Record

derivation_rule_specification [1..1] : String

Data_Element_Example

data_element_example_item [1..n] : String


Data_Element_Derivation

applied_to1..1

applying0..*

derivation_rule_application

Data_Element`

data_element_administration_record [1..1] : Administration_Record

representation_class_qualifier [0..1] : String

0..*

exemplified_by1..*

exemplifying

exemplification

0..*

1..1

expressing

expressed_by

data_element_concept_expression

0..* inputing0..*

input_to1..*

derivation_input

0..1 deriving0..1

derived_from1..*

derivation_output

Value_Domain

0..*

1..1

representing

represented_by 1..1

data_element_representation

Representation_Class

representation_class_administration_record [1..1] : Administration_Record

0..*

0..1

typed_by

typing

data_element_representation_class

0..*

0..1

typed_by 0..*

typing 0..1

value_domain_representation_class

data_element_precision [0..1] : Integer



Relationship to 18012 Interoperability

• Current 18012 status:– Part 1: Introduction– Part 2: Taxonomy and Lexicon– Part 3: Application Models

• At both 2001-01 and 2001-06 SC25/WG1, it was suggested that Part 4 be added:– Part 4: Registration Authority– Simplifies adoption and maintenance of 18012

series of documents


Example DCTP Binding of 18012

• Generically, the binding might look like:– PVAL lexicon_object lexicon_value

• Assuming registered in 18012-2 lexicon:– “LAMP” is a registered object– “OFF” and “ON” are registered values causing

actions “off” and “on”• Sample messages:

– PVAL LAMP OFF– PVAL LAMP ON

• MDIB (ISO/IEC 20944-*) binding:– mdib_putvalue(“LAMP”,“OFF”)– mdib_putvalue(“LAMP”,“ON”)


Methodology: Work Flow And Progressive Deliverables

Requirements

Functionality

Conceptual Model

Semantics

Bindings: APIs Bindings: Codings Bindings: Protocols

Encodings:Data Formats

Encodings: CallingConventions

Encodings: VariousCommunication Layers

The Steps of Building SuccessfulInformation Technology Standards/Specifications

“The work flow/steps promote(1) consensus-building, and

(2) long-term stability, interpretation, maintenance of

the standard/specification.”

“Consensus-building is incremental.”

“Interpretation/maintenance is stabilized: each level is dependent on higher levels.”

“Interpretation Examples:- Ambiguities in bindings are resolved by interpreting the semantics;- Ambiguities in semantics are resolved by interpreting the conceptual model.”

2003-02-19 SC25/WG1/N1028, Presentation on DCTP, ©2003 Farance Inc. 18Relatively Dynamic

Relatively Static

A Framework for Harmonization/Consistency ...Bindings: Codings, APIs, Protocols

Encodings: Calling Conventions, Data Formats, Communication LayersKeeping Pace with Technology: Long-Term vs. Short-Term Specs

Requirements

Functionality

Conceptual Model

Semantics

Bindings: Codings Bindings: Protocols



Bindings: APIs

Encodings:Calling Conventions

Topic-SpecificNormative Wording

Cross-Topic Codings,e.g.: XML, DNVP, ASN.1

Cross-Topic APIsInformative Wording

Cross-Topic APIsNormative Wording

e.g., Bindings in Java, C/C++, Perl,

JavaScript, Tcl

Topic-SpecificInformative Wording

Various Standards,e.g.:ASCII, 8859-1, UTF8

Cross-Topic Protocolse.g.: Presentation and

Session Layers

Various Standards, e.g.:Transport and Network

Layers


Interoperability (18012-1) Represents Higher Levels

Requirements

Functionality

Conceptual Model

Semantics




Bindings: APIs







JavaScript, Tcl




Session Layers


Layers


Data and Control Transfer Protocol(DCTP, ISO/IEC 15067-1) Is “Protocol-Like”

Requirements

Functionality

Conceptual Model

Semantics




Bindings: APIs







JavaScript, Tcl




Session Layers


Layers


Metadata Interoperability Bindings(ISO/IEC 20944-4x) Are “API-Like”

Requirements

Functionality

Conceptual Model

Semantics




Bindings: APIs







JavaScript, Tcl




Session Layers


Layers


APIs, Codings, Protocols —All Three Should Be Considered

Semantics

Bindings: APIs

Bindings: Codings

Bindings: Protocols

- Std APIs may be implemented viastd or proprietary Protocols- Std Protocols may be accessedby std or proprietary APIs- Both std APIs/Protocols improvewide area interoperability

- Std APIs may use std orproprietary Codings- Std Codings may be usedby std or proprietary APIs- Both std APIs/Codingsimprove portable apps/data

- Std Protocols may use std orproprietary Codings- Std Codings may be exchangedvia std or proprietary Protocols- Both std Protocols/Codingsimprove system interoperability

Harmonized standard APIs, Codings,and Protocols promote:- Application portability- Data portability- Multi-vendor, “open” solutions- Wide area, end-to-end interoperability

Prioritizing The Development OfStandards for Codings, APIs, and Protocols


Building Standards InSeveral Steps

Maintenance

Development

Review

Amendments: 2-3 yearsRevisions: 4-5 years

ConsensusBuilding

User/Vendor/Institutional/

Industry“Extensions”

“Extensions” Become Input ToNext Revision Of Standard

Industry-Relevant,Widely-Adopted

“Extensions”

The “Standard”


DCTP (15067-1) Messages Summary• CONN (connect): Connection to “repository”

– Can be ignored for simple controllers• OPEN (open): Establish session

– Can support multiple sessions– Simple controllers need only support single session

• NEGO RQAU: Request authentication/authorization– Security request

• NEGO RSAU: Respond authentication/authorization– Security response

• CLOS (close): Close session– Simple controllers can ignore

• DISC (disconnect): Disconnect from “repository”– Simple controllers can ignore


DCTP (15067-1) Messages Summary

• GSES: Get session parameters– Can be very simplistic

• PSES: Put session parameters– Can support multiple sessions– Simple controllers need only support single session

• GVAL: Get value (retrieve, variety of types)– Simple to implement for simple controllers

• PVAL: Put value (store, variety of types)– Simple to implement for simple controllers


DCTP (15067-1) Messages Summary

• LSOB: List “objects”– Easy to implement

• MKOB: New (make “object”)– Simple controllers can ignore

• RMOB: Destroy (remove “object”)– Simple controllers can ignore

• NOMD: Nomadic connection setup– Simple controllers can ignore

• GPTH: Get current path/view– Simple response for simple controllers

• PPTH: Put current path/view– Simple controllers can ignore


Integration With HomeGate

• Used inside the residential gateway• Can be used to bridge subnets for command

and control• Can be used an an intermediate language• Should be a standard, not a technical report• Definitely normative wording: implementations

will want to claim conformance


Integration With HomeGate

• Not required in a residential gateway because systems can choose to conform (or not) to ISO/IEC 15067-1

• Components can use proprietary bridging mechanism, if desired

• DCTP allows vendors to build “half-bridges” among subnets, which reduces integration complexity to N, not N*N

• Implementations already in C, C++, Perl, Java — all are small code size


Status of 15067-1 Document

• Draft 1, dated 2001-06-04• Draft 2, dated 2001-12-22• Draft 3, dated 2003-01-20

– Final WD for review by WG prior to CD submission– Review closed 2003-02-13, received one

comment

• Draft 4, CD submission

2003-02-19SC25/WG1/N1028, Presentation on DCTP, ©2003 Farance Inc.1 Presentation to SC25/WG1 On DCTP Status Presentation By Frank Farance, Farance Inc.

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