draft-ietf-ccamp-wson-iv-info-00.txt   draft-ietf-ccamp-wson-iv-info-01.txt 
CCAMP G. Martinelli, Ed. CCAMP G. Martinelli, Ed.
Internet-Draft Cisco Internet-Draft Cisco
Intended status: Informational X. Zhang, Ed. Intended status: Informational X. Zhang, Ed.
Expires: April 9, 2015 Huawei Technologies Expires: September 10, 2015 Huawei Technologies
G. Galimberti G. Galimberti
Cisco Cisco
A. Zanardi A. Zanardi
D. Siracusa D. Siracusa
F. Pederzolli F. Pederzolli
CREATE-NET CREATE-NET
Y. Lee Y. Lee
F. Zhang F. Zhang
Huawei Technologies Huawei Technologies
October 6, 2014 March 9, 2015
Information Model for Wavelength Switched Optical Networks (WSONs) with Information Model for Wavelength Switched Optical Networks (WSONs) with
Impairments Validation Impairments Validation
draft-ietf-ccamp-wson-iv-info-00 draft-ietf-ccamp-wson-iv-info-01
Abstract Abstract
This document defines an information model to support Impairment- This document defines an information model to support Impairment-
Aware (IA) Routing and Wavelength Assignment (RWA) functionality. Aware (IA) Routing and Wavelength Assignment (RWA) functionality.
This information model extends the information model for impairment- This information model extends the information model for impairment-
free RWA process in WSON to facilitate computation of paths where free RWA process in WSON to facilitate computation of paths where
optical impairment constraints need to considered. optical impairment constraints need to considered.
Status of This Memo Status of This Memo
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Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet- working documents as Internet-Drafts. The list of current Internet-
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Internet-Drafts are draft documents valid for a maximum of six months Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress." material or to cite them other than as "work in progress."
This Internet-Draft will expire on April 9, 2015. This Internet-Draft will expire on September 10, 2015.
Copyright Notice Copyright Notice
Copyright (c) 2014 IETF Trust and the persons identified as the Copyright (c) 2015 IETF Trust and the persons identified as the
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1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Definitions, Applicability and Properties . . . . . . . . . . 3 2. Definitions, Applicability and Properties . . . . . . . . . . 3
2.1. Definitions . . . . . . . . . . . . . . . . . . . . . . . 4 2.1. Definitions . . . . . . . . . . . . . . . . . . . . . . . 4
2.2. Applicability . . . . . . . . . . . . . . . . . . . . . . 4 2.2. Applicability . . . . . . . . . . . . . . . . . . . . . . 4
2.3. Properties . . . . . . . . . . . . . . . . . . . . . . . 5 2.3. Properties . . . . . . . . . . . . . . . . . . . . . . . 5
3. ITU-T List of Optical Parameters . . . . . . . . . . . . . . 6 3. ITU-T List of Optical Parameters . . . . . . . . . . . . . . 6
4. Background from WSON-RWA Information Model . . . . . . . . . 8 4. Background from WSON-RWA Information Model . . . . . . . . . 8
5. Optical Impairment Information Model . . . . . . . . . . . . 9 5. Optical Impairment Information Model . . . . . . . . . . . . 9
5.1. The Optical Impairment Vector . . . . . . . . . . . . . . 10 5.1. The Optical Impairment Vector . . . . . . . . . . . . . . 10
5.2. Node Information . . . . . . . . . . . . . . . . . . . . 10 5.2. Node Information . . . . . . . . . . . . . . . . . . . . 11
5.2.1. Impairment Matrix . . . . . . . . . . . . . . . . . . 10 5.2.1. Impairment Matrix . . . . . . . . . . . . . . . . . . 11
5.2.2. Impairment Resource Block Information . . . . . . . . 13 5.2.2. Impairment Resource Block Information . . . . . . . . 12
5.3. Link Information . . . . . . . . . . . . . . . . . . . . 13 5.3. Link Information . . . . . . . . . . . . . . . . . . . . 13
5.4. Path Information . . . . . . . . . . . . . . . . . . . . 13 5.4. Path Information . . . . . . . . . . . . . . . . . . . . 13
6. Encoding Considerations . . . . . . . . . . . . . . . . . . . 14 6. Encoding Considerations . . . . . . . . . . . . . . . . . . . 13
7. Control Plane Architectures . . . . . . . . . . . . . . . . . 14 7. Control Plane Architectures . . . . . . . . . . . . . . . . . 14
7.1. IV-Centralized . . . . . . . . . . . . . . . . . . . . . 15 7.1. IV-Centralized . . . . . . . . . . . . . . . . . . . . . 15
7.2. IV-Distributed . . . . . . . . . . . . . . . . . . . . . 15 7.2. IV-Distributed . . . . . . . . . . . . . . . . . . . . . 15
8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 15 8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 15
9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 15 9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 15
10. Security Considerations . . . . . . . . . . . . . . . . . . . 16 10. Security Considerations . . . . . . . . . . . . . . . . . . . 15
11. References . . . . . . . . . . . . . . . . . . . . . . . . . 16 11. References . . . . . . . . . . . . . . . . . . . . . . . . . 16
11.1. Normative References . . . . . . . . . . . . . . . . . . 16 11.1. Normative References . . . . . . . . . . . . . . . . . . 16
11.2. Informative References . . . . . . . . . . . . . . . . . 16 11.2. Informative References . . . . . . . . . . . . . . . . . 16
Appendix A. FAQ . . . . . . . . . . . . . . . . . . . . . . . . 17 Appendix A. FAQ . . . . . . . . . . . . . . . . . . . . . . . . 17
A.1. Why the Application Code does not suffice for Optical A.1. Why the Application Code does not suffice for Optical
Impairment Validation? . . . . . . . . . . . . . . . . . 17 Impairment Validation? . . . . . . . . . . . . . . . . . 17
A.2. Are DWDM network multivendor? . . . . . . . . . . . . . . 17 A.2. Are DWDM network multivendor? . . . . . . . . . . . . . . 17
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 17 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 17
1. Introduction 1. Introduction
In the context of Wavelength Switched Optical Network (WSON), In the context of Wavelength Switched Optical Network (WSON),
[RFC6163] describes the basic framework for a GMPLS and PCE-based [RFC6163] describes the basic framework for a GMPLS and PCE-based
Routing and Wavelength Assignment (RWA) control plane. The Routing and Wavelength Assignment (RWA) control plane. The
associated information model [I-D.ietf-ccamp-rwa-info] defines associated information model [RFC7446] defines information/parameters
information/parameters required by an RWA process without optical required by an RWA process without optical impairment considerations.
impairment considerations.
There are cases of WSON where optical impairments play a significant There are cases of WSON where optical impairments play a significant
role and are considered as important constraints. The framework role and are considered as important constraints. The framework
document [RFC6566] defines the problem scope and related control document [RFC6566] defines the problem scope and related control
plane architectural options for the Impairment Aware RWA (IA-RWA) plane architectural options for the Impairment Aware RWA (IA-RWA)
operation. Options include different combinations of Impairment operation. Options include different combinations of Impairment
Validation (IV) and RWA functions in term of different combination of Validation (IV) and RWA functions in term of different combination of
control plane functions (i.e., PCE, Routing, Signaling). control plane functions (i.e., PCE, Routing, Signaling).
A Control Plane with RWA-IA will not be able to solve the optical A Control Plane with RWA-IA will not be able to solve the optical
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and the GMPLS control plane will follow its usual procedures upon and the GMPLS control plane will follow its usual procedures upon
errors and failures. A control plane will not replace a the network errors and failures. A control plane will not replace a the network
design phase that remains a foundamental step for DWDM Optical design phase that remains a foundamental step for DWDM Optical
Networks. As the non-linear impairments which need to be considered Networks. As the non-linear impairments which need to be considered
in the calculation of an optical path will be vendor-dependent, the in the calculation of an optical path will be vendor-dependent, the
parameters considered in this document is not an exhaustive list. parameters considered in this document is not an exhaustive list.
This document provides an information model for the impairment aware This document provides an information model for the impairment aware
case to allow the impairment validation function implemented in the case to allow the impairment validation function implemented in the
control plane or enabled by control plane available information. control plane or enabled by control plane available information.
This model goes in addition to [I-D.ietf-ccamp-rwa-info] and shall This model goes in addition to [RFC7446] and shall support any
support any control plane architectural option described by the control plane architectural option described by the framework
framework document (see sections 4.2 and 4.3 of [RFC6566]) where a document (see sections 4.2 and 4.3 of [RFC6566]) where a set of
set of combinations of control plane functions vs. IV function is combinations of control plane functions vs. IV function is provided.
provided.
2. Definitions, Applicability and Properties 2. Definitions, Applicability and Properties
This section provides some concepts to help understand the model and This section provides some concepts to help understand the model and
to make a clear separation from data plane definitions (ITU-T to make a clear separation from data plane definitions (ITU-T
recommendations). The first sub-section provides definitions while recommendations). The first sub-section provides definitions while
the Applicability sections uses the defined definitions to scope this the Applicability sections uses the defined definitions to scope this
document. document.
2.1. Definitions 2.1. Definitions
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G-3 Polarization Mode Dispersion (PMD). Section 9.3 G-3 Polarization Mode Dispersion (PMD). Section 9.3
G-4 Polarization Dependent Loss (PDL). Section 9.3 G-4 Polarization Dependent Loss (PDL). Section 9.3
In addition to the above, the following list of parameters has been In addition to the above, the following list of parameters has been
mentioned by [LS78]: mentioned by [LS78]:
L-1 "Channel frequency range", [ITU.G671]. This parameter is part L-1 "Channel frequency range", [ITU.G671]. This parameter is part
of the application code and encoded through Optical Interface of the application code and encoded through Optical Interface
Class as defined in [I-D.ietf-ccamp-rwa-info]. Class as defined in [RFC7446].
L-2 "Modulation format and rate". This parameter is part of the L-2 "Modulation format and rate". This parameter is part of the
application code and encoded through Optical Interface Class as application code and encoded through Optical Interface Class as
defined in [I-D.ietf-ccamp-rwa-info]. defined in [RFC7446].
L-3 "Channel power". Required by G-1. L-3 "Channel power". Required by G-1.
L-4 "Ripple". According to [ITU.G680], this parameter can be taken L-4 "Ripple". According to [ITU.G680], this parameter can be taken
into account as additional OSNR penalty. into account as additional OSNR penalty.
L-5 "Channel signal-spontaneous noise figure", [ITU.G680]. L-5 "Channel signal-spontaneous noise figure", [ITU.G680].
Required by OSNR calculation (see G-1) above. Required by OSNR calculation (see G-1) above.
L-6 "Channel chromatic dispersion (for fibre segment or network L-6 "Channel chromatic dispersion (for fibre segment or network
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L-15 "Non-linear coefficient (for a fibre segment)", [ITU.G650.2]. L-15 "Non-linear coefficient (for a fibre segment)", [ITU.G650.2].
Required for Non-Linear Optical Impairment Computational Required for Non-Linear Optical Impairment Computational
Models. Neglected by this document. Models. Neglected by this document.
The final list of parameters is G-1, G-2, G-3, G-4, L-3, L-4, L-5, The final list of parameters is G-1, G-2, G-3, G-4, L-3, L-4, L-5,
L-8, L-11, L-12, L-13, L-14. L-8, L-11, L-12, L-13, L-14.
4. Background from WSON-RWA Information Model 4. Background from WSON-RWA Information Model
In this section we report terms already defined for the WSON-RWA In this section we report terms already defined for the WSON-RWA
(impairment free) as in [I-D.ietf-ccamp-rwa-info] and (impairment free) as in [RFC7446] and
[I-D.ietf-ccamp-general-constraint-encode]. The purpose is to [I-D.ietf-ccamp-general-constraint-encode]. The purpose is to
provide essential information that will be reused or extended for the provide essential information that will be reused or extended for the
impairment case. impairment case.
In particular [I-D.ietf-ccamp-rwa-info] defines the connectivity In particular [RFC7446] Section 4.1 defines the ConnectivityMatrix
matrix as the following: explaing that it does not represent any particular internal blocking
behavior but indicates which input ports and wavelengths could
ConnectivityMatrix ::= <MatrixID> <ConnType> <Matrix> possibly be connected to a particular output port.
<ConnectivityMatrix> ::= <MatrixID> <ConnType> <Matrix>
According to [I-D.ietf-ccamp-general-constraint-encode], this According to [I-D.ietf-ccamp-general-constraint-encode], this
definition is further detailed as: definition is further detailed as:
ConnectivityMatrix ::= <ConnectivityMatrix> ::=
<MatrixID> <ConnType> ((<LinkSet> <LinkSet>) ...) <MatrixID> <ConnType> ((<LinkSet> <LinkSet>) ...)
This second formula highlights how the connectivity matrix is built This second formula highlights how the ConnectivityMatrix is built by
by pairs of LinkSet objects identifying the internal connectivity pairs of LinkSet objects identifying the internal connectivity
capability due to internal optical node constraint(s). It's capability due to internal optical node constraint(s). It's
essentially binary information and tell if a wavelength or a set of essentially binary information and tell if a wavelength or a set of
wavelengths can go from an input port to an output port. wavelengths can go from an input port to an output port.
As an additional note, connectivity matrix belongs to node As an additional note, ConnectivityMatrix belongs to node
information and is purely static. Dynamic information related to the information, is uniquely identified by adverstising node and is a
actual usage of the connections is available through specific static information. Dynamic information related to the actual state
extension to link information. of connections is available through specific extension to link
information.
Furthermore [I-D.ietf-ccamp-rwa-info] define the resource block as The [RFC7446] introduces the concept of ResourceBlockInfo and
follow: ResourcePool for the WSON nodes. The resource block is a collection
of resources behaving in the same way and having similar
characteristics. The ResourceBlockInfo is defined as follow:
ResourceBlockInfo ::= <ResourceBlockSet> [<InputConstraints>] <ResourceBlockInfo> ::= <ResourceBlockSet> [<InputConstraints>]
[<ProcessingCapabilities>] [<OutputConstraints>] [<ProcessingCapabilities>] [<OutputConstraints>]
Which is an efficient way to model constrains of a WSON node. The usage of resorurce block and resource pool is an efficient way to
model constrains within a WSON node.
5. Optical Impairment Information Model 5. Optical Impairment Information Model
The idea behind this information model is to categorize the The idea behind this information model is to categorize the
impairment parameters into three types and extend the information impairment parameters into three types and extend the information
model already defined for impairment-free WSONs. The three model already defined for impairment-free WSONs. The three
categories are: categories are:
o Node Information. The concept of connectivity matrix is reused o Node Information. The concept of connectivity matrix is reused
and extended to introduce an impairment matrix, which represents and extended to introduce an impairment matrix, which represents
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of a network element. Wavelength dependency property of optical of a network element. Wavelength dependency property of optical
paramters is also considered. paramters is also considered.
ImpairmentMatrix ::= <MatrixID> <ConnType> ImpairmentMatrix ::= <MatrixID> <ConnType>
((<LinkSet> <LinkSet> <OIV>) ...) ((<LinkSet> <LinkSet> <OIV>) ...)
Where: Where:
MatrixID. This ID is a unique identifier for the matrix. It MatrixID. This ID is a unique identifier for the matrix. It
shall be unique in scope among connectivity matrices defined in shall be unique in scope among connectivity matrices defined in
[I-D.ietf-ccamp-rwa-info] and impairment matrices defined here. [RFC7446] and impairment matrices defined here.
ConnType. This number identifies the type of matrix and it shall ConnType. This number identifies the type of matrix and it shall
be unique in scope with other values defined by impairment-free be unique in scope with other values defined by impairment-free
WSON documents. WSON documents.
LinkSet. Same object definition and usage as LinkSet. Same object definition and usage as
[I-D.ietf-ccamp-general-constraint-encode]. The pairs of LinkSet [I-D.ietf-ccamp-general-constraint-encode]. The pairs of LinkSet
identify one or more internal node constrain. identify one or more internal node constrain.
OIV. The Optical Impairment Vector defined above. OIV. The Optical Impairment Vector defined above.
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binary information through the Optical Impairment Vector associated binary information through the Optical Impairment Vector associated
with each LinkSet pair. Optical parameters in the picture are with each LinkSet pair. Optical parameters in the picture are
reported just as examples while details go into specific encoding reported just as examples while details go into specific encoding
draft [I-D.martinelli-ccamp-wson-iv-encode]. draft [I-D.martinelli-ccamp-wson-iv-encode].
This representation shows the most general case however, the total This representation shows the most general case however, the total
amount of information transported by control plane protocols can be amount of information transported by control plane protocols can be
greatly reduced by proper encoding when the same set of values apply greatly reduced by proper encoding when the same set of values apply
to all LinkSet pairs. to all LinkSet pairs.
[EDITOR NODE: first run of the information model does looks for
generality not for optimizing the quantity of information. We'll
deal with optimization in a further step.]
5.2.2. Impairment Resource Block Information 5.2.2. Impairment Resource Block Information
This information model reuses the definition of Resource Block This information model reuses the definition of Resource Block
Information adding the associated impairment vector. Information adding the associated impairment vector.
ResourceBlockInfo ::= <ResourceBlockSet> [<InputConstraints>] ResourceBlockInfo ::= <ResourceBlockSet> [<InputConstraints>]
[<ProcessingCapabilities>] [<OutputConstraints>] [<OIV>] [<ProcessingCapabilities>] [<OutputConstraints>] [<OIV>]
The object ResourceBlockInfo is than used as specified within The object ResourceBlockInfo is than used as specified within
[I-D.ietf-ccamp-rwa-info]. [RFC7446].
5.3. Link Information 5.3. Link Information
For the list of optical parameters associated to the link, the same For the list of optical parameters associated to the link, the same
approach used for the node-specific impairment information can be approach used for the node-specific impairment information can be
applied. The link-specific impairment information is extended from applied. The link-specific impairment information is extended from
[I-D.ietf-ccamp-rwa-info] as the following: [RFC7446] as the following:
<DynamicLinkInfo> ::= <LinkID> <AvailableLabels> <DynamicLinkInfo> ::= <LinkID> <AvailableLabels>
[<SharedBackupLabels>] [<OIV>] [<SharedBackupLabels>] [<OIV>]
DynamicLinkInfo is already defined in [I-D.ietf-ccamp-rwa-info] while DynamicLinkInfo is already defined in [RFC7446] while OIV is the
OIV is the Optical Impairment Vector is defined in the previous Optical Impairment Vector is defined in the previous section.
section.
5.4. Path Information 5.4. Path Information
There are cases where the optical impariments can only be described There are cases where the optical impariments can only be described
as a contrains on the overall end to end path. In such case, the as a contrains on the overall end to end path. In such case, the
optical impariment and/or parameter, cannot be derived (using a optical impariment and/or parameter, cannot be derived (using a
simple function) from the set of node / link contributions. simple function) from the set of node / link contributions.
An equivalent case is the option reported by [RFC6566] on IV- An equivalent case is the option reported by [RFC6566] on IV-
Candidate paths where, the control plane knows a list of optically Candidate paths where, the control plane knows a list of optically
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[ITU.G697] [ITU.G697]
International Telecommunications Union, "Optical International Telecommunications Union, "Optical
monitoring for dense wavelength division multiplexing monitoring for dense wavelength division multiplexing
systems", ITU-T Recommendation G.697, February 2012. systems", ITU-T Recommendation G.697, February 2012.
11.2. Informative References 11.2. Informative References
[I-D.ietf-ccamp-general-constraint-encode] [I-D.ietf-ccamp-general-constraint-encode]
Bernstein, G., Lee, Y., Li, D., and W. Imajuku, "General Bernstein, G., Lee, Y., Li, D., and W. Imajuku, "General
Network Element Constraint Encoding for GMPLS Controlled Network Element Constraint Encoding for GMPLS Controlled
Networks", draft-ietf-ccamp-general-constraint-encode-15 Networks", draft-ietf-ccamp-general-constraint-encode-20
(work in progress), August 2014. (work in progress), February 2015.
[I-D.ietf-ccamp-rwa-info]
Lee, Y., Bernstein, G., Li, D., and W. Imajuku, "Routing
and Wavelength Assignment Information Model for Wavelength
Switched Optical Networks", draft-ietf-ccamp-rwa-info-21
(work in progress), February 2014.
[I-D.martinelli-ccamp-wson-iv-encode] [I-D.martinelli-ccamp-wson-iv-encode]
Martinelli, G., Zhang, X., Galimberti, G., Siracusa, D., Martinelli, G., Zhang, X., Galimberti, G., Siracusa, D.,
Zanardi, A., Pederzolli, F., Lee, Y., and F. Zhang, Zanardi, A., Pederzolli, F., Lee, Y., and F. Zhang,
"Information Encoding for WSON with Impairments "Information Encoding for WSON with Impairments
Validation", draft-martinelli-ccamp-wson-iv-encode-04 Validation", draft-martinelli-ccamp-wson-iv-encode-04
(work in progress), July 2014. (work in progress), July 2014.
[LS78] International Telecommunications Union SG15/Q6, "LS/s on [LS78] International Telecommunications Union SG15/Q6, "LS/s on
CCAMP Liaison to ITU-T SG15 Q6 and Q12 on WSON", LS CCAMP Liaison to ITU-T SG15 Q6 and Q12 on WSON", LS
skipping to change at page 17, line 18 skipping to change at page 17, line 5
[RFC6163] Lee, Y., Bernstein, G., and W. Imajuku, "Framework for [RFC6163] Lee, Y., Bernstein, G., and W. Imajuku, "Framework for
GMPLS and Path Computation Element (PCE) Control of GMPLS and Path Computation Element (PCE) Control of
Wavelength Switched Optical Networks (WSONs)", RFC 6163, Wavelength Switched Optical Networks (WSONs)", RFC 6163,
April 2011. April 2011.
[RFC6566] Lee, Y., Bernstein, G., Li, D., and G. Martinelli, "A [RFC6566] Lee, Y., Bernstein, G., Li, D., and G. Martinelli, "A
Framework for the Control of Wavelength Switched Optical Framework for the Control of Wavelength Switched Optical
Networks (WSONs) with Impairments", RFC 6566, March 2012. Networks (WSONs) with Impairments", RFC 6566, March 2012.
[RFC7446] Lee, Y., Bernstein, G., Li, D., and W. Imajuku, "Routing
and Wavelength Assignment Information Model for Wavelength
Switched Optical Networks", RFC 7446, February 2015.
Appendix A. FAQ Appendix A. FAQ
A.1. Why the Application Code does not suffice for Optical Impairment A.1. Why the Application Code does not suffice for Optical Impairment
Validation? Validation?
Application Codes are encoded within GMPLS WSON protocol through the Application Codes are encoded within GMPLS WSON protocol through the
Optical Interface Class as defined in [I-D.ietf-ccamp-rwa-info]. Optical Interface Class as defined in [RFC7446].
The purpose of the Application Code in RWA is simply to assess the The purpose of the Application Code in RWA is simply to assess the
interface compatibility: same Application Code means that two interface compatibility: same Application Code means that two
interfaces can have an LSP connecting the two. interfaces can have an LSP connecting the two.
Application Codes contain other information useful for IV process Application Codes contain other information useful for IV process
(e.g., see the list of parameters) so they are required however (e.g., see the list of parameters) so they are required however
Computational Models requires more parameteres to assess the path Computational Models requires more parameteres to assess the path
feasibility. feasibility.
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