draft-ietf-ccamp-rwa-info-11.txt   draft-ietf-ccamp-rwa-info-12.txt 
Network Working Group Y. Lee Network Working Group Y. Lee
Internet Draft Huawei Internet Draft Huawei
Intended status: Informational G. Bernstein Intended status: Informational G. Bernstein
Expires: September 2011 Grotto Networking Expires: March 2012 Grotto Networking
D. Li D. Li
Huawei Huawei
W. Imajuku W. Imajuku
NTT NTT
March 14, 2011 September 9, 2011
Routing and Wavelength Assignment Information Model for Wavelength Routing and Wavelength Assignment Information Model for Wavelength
Switched Optical Networks Switched Optical Networks
draft-ietf-ccamp-rwa-info-11.txt draft-ietf-ccamp-rwa-info-12.txt
Status of this Memo Status of this Memo
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Copyright Notice Copyright Notice
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Abstract Abstract
This document provides a model of information needed by the routing This document provides a model of information needed by the routing
and wavelength assignment (RWA) process in wavelength switched and wavelength assignment (RWA) process in wavelength switched
optical networks (WSONs). The purpose of the information described optical networks (WSONs). The purpose of the information described
in this model is to facilitate constrained optical path computation in this model is to facilitate constrained lightpath computation in
in WSONs. This model takes into account compatibility constraints WSONs. This model takes into account compatibility constraints
between WSON signal attributes and network elements but does not between WSON signal attributes and network elements but does not
include constraints due to optical impairments. Aspects of this include constraints due to optical impairments. Aspects of this
information that may be of use to other technologies utilizing a information that may be of use to other technologies utilizing a
GMPLS control plane are discussed. GMPLS control plane are discussed.
Table of Contents Table of Contents
1. Introduction...................................................3 1. Introduction...................................................3
1.1. Revision History..........................................4 1.1. Revision History..........................................4
1.1.1. Changes from 01......................................4 1.1.1. Changes from 01......................................4
1.1.2. Changes from 02......................................4 1.1.2. Changes from 02......................................4
1.1.3. Changes from 03......................................4 1.1.3. Changes from 03......................................5
1.1.4. Changes from 04......................................5 1.1.4. Changes from 04......................................5
1.1.5. Changes from 05......................................5 1.1.5. Changes from 05......................................5
1.1.6. Changes from 06......................................5 1.1.6. Changes from 06......................................5
1.1.7. Changes from 07......................................5 1.1.7. Changes from 07......................................5
1.1.8. Changes from 08......................................5 1.1.8. Changes from 08......................................5
1.1.9. Changes from 09......................................5 1.1.9. Changes from 09......................................5
1.1.10. Changes from 10.....................................6 1.1.10. Changes from 10.....................................6
1.1.11. Changes from 11.....................................6
2. Terminology....................................................6 2. Terminology....................................................6
3. Routing and Wavelength Assignment Information Model............6 3. Routing and Wavelength Assignment Information Model............7
3.1. Dynamic and Relatively Static Information.................7 3.1. Dynamic and Relatively Static Information.................7
4. Node Information (General).....................................7 4. Node Information (General).....................................7
4.1. Connectivity Matrix.......................................8 4.1. Connectivity Matrix.......................................8
4.2. Shared Risk Node Group....................................8 4.2. Shared Risk Node Group....................................9
5. Node Information (WSON specific)...............................9 5. Node Information (WSON specific)...............................9
5.1. Resource Accessibility/Availability......................10 5.1. Resource Accessibility/Availability......................10
5.2. Resource Signal Constraints and Processing Capabilities..14 5.2. Resource Signal Constraints and Processing Capabilities..14
5.3. Compatibility and Capability Details.....................15 5.3. Compatibility and Capability Details.....................15
5.3.1. Shared Ingress or Egress Indication.................15 5.3.1. Shared Input or Output Indication...................15
5.3.2. Modulation Type List................................15 5.3.2. Modulation Type List................................15
5.3.3. FEC Type List.......................................15 5.3.3. FEC Type List.......................................15
5.3.4. Bit Rate Range List.................................15 5.3.4. Bit Rate Range List.................................15
5.3.5. Acceptable Client Signal List.......................16 5.3.5. Acceptable Client Signal List.......................16
5.3.6. Processing Capability List..........................16 5.3.6. Processing Capability List..........................16
6. Link Information (General)....................................16 6. Link Information (General)....................................16
6.1. Administrative Group.....................................17 6.1. Administrative Group.....................................17
6.2. Interface Switching Capability Descriptor................17 6.2. Interface Switching Capability Descriptor................17
6.3. Link Protection Type (for this link).....................17 6.3. Link Protection Type (for this link).....................17
6.4. Shared Risk Link Group Information.......................17 6.4. Shared Risk Link Group Information.......................17
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11.1. Normative References....................................23 11.1. Normative References....................................23
11.2. Informative References..................................24 11.2. Informative References..................................24
12. Contributors.................................................25 12. Contributors.................................................25
Author's Addresses...............................................25 Author's Addresses...............................................25
Intellectual Property Statement..................................26 Intellectual Property Statement..................................26
Disclaimer of Validity...........................................27 Disclaimer of Validity...........................................27
1. Introduction 1. Introduction
The purpose of the following information model for WSONs is to The purpose of the following information model for WSONs is to
facilitate constrained optical path computation and as such is not a facilitate constrained lightpath computation and as such is not a
general purpose network management information model. This constraint general purpose network management information model. This constraint
is frequently referred to as the "wavelength continuity" constraint, is frequently referred to as the "wavelength continuity" constraint,
and the corresponding constrained optical path computation is known and the corresponding constrained lightpath computation is known as
as the routing and wavelength assignment (RWA) problem. Hence the the routing and wavelength assignment (RWA) problem. Hence the
information model must provide sufficient topology and wavelength information model must provide sufficient topology and wavelength
restriction and availability information to support this computation. restriction and availability information to support this computation.
More details on the RWA process and WSON subsystems and their More details on the RWA process and WSON subsystems and their
properties can be found in [WSON-Frame]. The model defined here properties can be found in [RFC6163]. The model defined here includes
includes constraints between WSON signal attributes and network constraints between WSON signal attributes and network elements, but
elements, but does not include optical impairments. does not include optical impairments.
In addition to presenting an information model suitable for path In addition to presenting an information model suitable for path
computation in WSON, this document also highlights model aspects that computation in WSON, this document also highlights model aspects that
may have general applicability to other technologies utilizing a may have general applicability to other technologies utilizing a
GMPLS control plane. The portion of the information model applicable GMPLS control plane. The portion of the information model applicable
to other technologies beyond WSON is referred to as "general" to to other technologies beyond WSON is referred to as "general" to
distinguish it from the "WSON-specific" portion that is applicable distinguish it from the "WSON-specific" portion that is applicable
only to WSON technology. only to WSON technology.
1.1. Revision History 1.1. Revision History
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Section 5.2: Formatting fixes. Section 5.2: Formatting fixes.
1.1.10. Changes from 10 1.1.10. Changes from 10
Enhanced the explanation of shared fiber access to resources and Enhanced the explanation of shared fiber access to resources and
updated Figure 2 to show a more general situation to be modeled. updated Figure 2 to show a more general situation to be modeled.
Removed all 1st person idioms. Removed all 1st person idioms.
1.1.11. Changes from 11
Replace all instances of "ingress" with "input" and all instances of
"egress" with "output". Added clarifying text on relationship between
resource block model and physical entities such as line cards.
2. Terminology 2. Terminology
CWDM: Coarse Wavelength Division Multiplexing. CWDM: Coarse Wavelength Division Multiplexing.
DWDM: Dense Wavelength Division Multiplexing. DWDM: Dense Wavelength Division Multiplexing.
FOADM: Fixed Optical Add/Drop Multiplexer. FOADM: Fixed Optical Add/Drop Multiplexer.
ROADM: Reconfigurable Optical Add/Drop Multiplexer. A reduced port ROADM: Reconfigurable Optical Add/Drop Multiplexer. A reduced port
count wavelength selective switching element featuring ingress and count wavelength selective switching element featuring input and
egress line side ports as well as add/drop side ports. output line side ports as well as add/drop side ports.
RWA: Routing and Wavelength Assignment. RWA: Routing and Wavelength Assignment.
Wavelength Conversion. The process of converting an information Wavelength Conversion. The process of converting an information
bearing optical signal centered at a given wavelength to one with bearing optical signal centered at a given wavelength to one with
"equivalent" content centered at a different wavelength. Wavelength "equivalent" content centered at a different wavelength. Wavelength
conversion can be implemented via an optical-electronic-optical (OEO) conversion can be implemented via an optical-electronic-optical (OEO)
process or via a strictly optical process. process or via a strictly optical process.
WDM: Wavelength Division Multiplexing. WDM: Wavelength Division Multiplexing.
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Note that multiple connectivity matrices are allowed and hence can Note that multiple connectivity matrices are allowed and hence can
fully support the most general cases enumerated in [Switch]. fully support the most general cases enumerated in [Switch].
4.1. Connectivity Matrix 4.1. Connectivity Matrix
The connectivity matrix (ConnectivityMatrix) represents either the The connectivity matrix (ConnectivityMatrix) represents either the
potential connectivity matrix for asymmetric switches (e.g. ROADMs potential connectivity matrix for asymmetric switches (e.g. ROADMs
and such) or fixed connectivity for an asymmetric device such as a and such) or fixed connectivity for an asymmetric device such as a
multiplexer. Note that this matrix does not represent any particular multiplexer. Note that this matrix does not represent any particular
internal blocking behavior but indicates which ingress ports and internal blocking behavior but indicates which inputinput ports and
wavelengths could possibly be connected to a particular output port. wavelengths could possibly be connected to a particular output port.
Representing internal state dependent blocking for a switch or ROADM Representing internal state dependent blocking for a switch or ROADM
is beyond the scope of this document and due to its highly is beyond the scope of this document and due to its highly
implementation dependent nature would most likely not be subject to implementation dependent nature would most likely not be subject to
standardization in the future. The connectivity matrix is a standardization in the future. The connectivity matrix is a
conceptual M by N matrix representing the potential switched or fixed conceptual M by N matrix representing the potential switched or fixed
connectivity, where M represents the number of ingress ports and N connectivity, where M represents the number of inputinput ports and N
the number of egress ports. This is a "conceptual" matrix since the the number of outputoutput ports. This is a "conceptual" matrix since
matrix tends to exhibit structure that allows for very compact the matrix tends to exhibit structure that allows for very compact
representations that are useful for both transmission and path representations that are useful for both transmission and path
computation [Encode]. computation [Encode].
Note that the connectivity matrix information element can be useful Note that the connectivity matrix information element can be useful
in any technology context where asymmetric switches are utilized. in any technology context where asymmetric switches are utilized.
ConnectivityMatrix ::= <MatrixID> <ConnType> <Matrix> ConnectivityMatrix ::= <MatrixID> <ConnType> <Matrix>
Where Where
<MatrixID> is a unique identifier for the matrix. <MatrixID> is a unique identifier for the matrix.
<ConnType> can be either 0 or 1 depending upon whether the <ConnType> can be either 0 or 1 depending upon whether the
connectivity is either fixed or potentially switched. connectivity is either fixed or potentially switched.
<Matrix> represents the fixed or switched connectivity in that <Matrix> represents the fixed or switched connectivity in that
Matrix(i, j) = 0 or 1 depending on whether ingress port i can connect Matrix(i, j) = 0 or 1 depending on whether inputinput port i can
to egress port j for one or more wavelengths. connect to outputoutput port j for one or more wavelengths.
4.2. Shared Risk Node Group 4.2. Shared Risk Node Group
SRNG: Shared risk group for nodes. The concept of a shared risk link SRNG: Shared risk group for nodes. The concept of a shared risk link
group was defined in [RFC4202]. This can be used to achieve a desired group was defined in [RFC4202]. This can be used to achieve a desired
"amount" of link diversity. It is also desirable to have a similar "amount" of link diversity. It is also desirable to have a similar
capability to achieve various degrees of node diversity. This is capability to achieve various degrees of node diversity. This is
explained in [G.7715]. Typical risk groupings for nodes can include explained in [G.7715]. Typical risk groupings for nodes can include
those nodes in the same building, within the same city, or geographic those nodes in the same building, within the same city, or geographic
region. region.
Since the failure of a node implies the failure of all links Since the failure of a node implies the failure of all links
associated with that node a sufficiently general shared risk link associated with that node a sufficiently general shared risk link
group (SRLG) encoding, such as that used in GMPLS routing extensions group (SRLG) encoding, such as that used in GMPLS routing extensions
can explicitly incorporate SRNG information. can explicitly incorporate SRNG information.
5. Node Information (WSON specific) 5. Node Information (WSON specific)
As discussed in [WSON-Frame] a WSON node may contain electro-optical As discussed in [RFC6163] a WSON node may contain electro-optical
subsystems such as regenerators, wavelength converters or entire subsystems such as regenerators, wavelength converters or entire
switching subsystems. The model present here can be used in switching subsystems. The model present here can be used in
characterizing the accessibility and availability of limited characterizing the accessibility and availability of limited
resources such as regenerators or wavelength converters as well as resources such as regenerators or wavelength converters as well as
WSON signal attribute constraints of electro-optical subsystems. As WSON signal attribute constraints of electro-optical subsystems. As
such this information element is fairly specific to WSON such this information element is fairly specific to WSON
technologies. technologies.
A WSON node may include regenerators or wavelength converters A WSON node may include regenerators or wavelength converters
arranged in a shared pool. As discussed in [WSON-Frame] this can arranged in a shared pool. As discussed in [RFC6163] this can include
include OEO based WDM switches as well. There are a number of OEO based WDM switches as well. There are a number of different
different approaches used in the design of WDM switches containing approaches used in the design of WDM switches containing regenerator
regenerator or converter pools. However, from the point of view of or converter pools. However, from the point of view of path
path computation the following need to be known: computation the following need to be known:
1. The nodes that support regeneration or wavelength conversion. 1. The nodes that support regeneration or wavelength conversion.
2. The accessibility and availability of a wavelength converter to 2. The accessibility and availability of a wavelength converter to
convert from a given ingress wavelength on a particular ingress convert from a given inputinput wavelength on a particular
port to a desired egress wavelength on a particular egress port. inputinput port to a desired outputoutput wavelength on a
particular outputoutput port.
3. Limitations on the types of signals that can be converted and the 3. Limitations on the types of signals that can be converted and the
conversions that can be performed. conversions that can be performed.
For modeling purposes and encoding efficiency identical processing Since resources tend to be packaged together in blocks of similar
resources such as regenerators or wavelength converters with devices, e.g., on line cards or other types of modules, the
identical limitations, and processing and accessibility properties fundamental unit of identifiable resource in this document is the
are grouped into "blocks". Such blocks can consist of a single "resource block". A resource block may contain one or more resources.
resource, though grouping resources into blocks leads to more As resource blocks are the smallest identifiable unit of processing
efficient encodings. The resource pool model is composed of one or resource, one can group together resources into blocks if they have
more resource blocks where the accessibility to and from any resource similar characteristics relevant to the optical system being modeled,
within a block is the same. e.g., processing properties, accessibility, etc.
This leads to the following formal high level model: This leads to the following formal high level model:
<Node_Information> ::= <Node_ID> [<ConnectivityMatrix>...] <Node_Information> ::= <Node_ID> [<ConnectivityMatrix>...]
[<ResourcePool>] [<ResourcePool>]
Where Where
<ResourcePool> ::= <ResourceBlockInfo>... <ResourcePool> ::= <ResourceBlockInfo>...
[<ResourceBlockAccessibility>...] [<ResourceWaveConstraints>...] [<ResourceAccessibility>...] [<ResourceWaveConstraints>...]
[<RBPoolState>] [<RBPoolState>]
First the accessibility of resource blocks is addressed then their First the accessibility of resource blocks is addressed then their
properties are discussed. properties are discussed.
5.1. Resource Accessibility/Availability 5.1. Resource Accessibility/Availability
A similar technique as used to model ROADMs and optical switches can A similar technique as used to model ROADMs and optical switches can
be used to model regenerator/converter accessibility. This technique be used to model regenerator/converter accessibility. This technique
was generally discussed in [WSON-Frame] and consisted of a matrix to was generally discussed in [RFC6163] and consisted of a matrix to
indicate possible connectivity along with wavelength constraints for indicate possible connectivity along with wavelength constraints for
links/ports. Since regenerators or wavelength converters may be links/ports. Since regenerators or wavelength converters may be
considered a scarce resource it is desirable that the model include, considered a scarce resource it is desirable that the model include,
if desired, the usage state (availability) of individual regenerators if desired, the usage state (availability) of individual regenerators
or converters in the pool. Models that incorporate more state to or converters in the pool. Models that incorporate more state to
further reveal blocking conditions on ingress or egress to particular further reveal blocking conditions on input or output to particular
converters are for further study and not included here. converters are for further study and not included here.
The three stage model is shown schematically in Figure 1 and Figure The three stage model is shown schematically in Figure 1 and Figure
2. The difference between the two figures is that Figure 1 assumes 2. The difference between the two figures is that Figure 1 assumes
that each signal that can get to a resource block may do so, while in that each signal that can get to a resource block may do so, while in
Figure 2 the access to sets of resource blocks is via a shared fiber Figure 2 the access to sets of resource blocks is via a shared fiber
which imposes its own wavelength collision constraint. The which imposes its own wavelength collision constraint. The
representation of Figure 1 can have more than one ingress to each representation of Figure 1 can have more than one input to each
resource block since each ingress represents a single wavelength resource block since each input represents a single wavelength
signal, while in Figure 2 shows a single multiplexed WDM ingress or signal, while in Figure 2 shows a single multiplexed WDM inputinput
egress, e.g., a fiber, to/from each set of block. or output, e.g., a fiber, to/from each set of block.
This model assumes N ingress ports (fibers), P resource blocks This model assumes N input ports (fibers), P resource blocks
containing one or more identical resources (e.g. wavelength containing one or more identical resources (e.g. wavelength
converters), and M egress ports (fibers). Since not all ingress ports converters), and M output ports (fibers). Since not all input ports
can necessarily reach each resource block, the model starts with a can necessarily reach each resource block, the model starts with a
resource pool ingress matrix RI(i,p) = {0,1} whether ingress port i resource pool input matrix RI(i,p) = {0,1} whether input port i can
can reach potentially reach resource block p. reach potentially reach resource block p.
Since not all wavelengths can necessarily reach all the resources or Since not all wavelengths can necessarily reach all the resources or
the resources may have limited input wavelength range the model has a the resources may have limited input wavelength range the model has a
set of relatively static ingress port constraints for each resource. set of relatively static input port constraints for each resource. In
In addition, if the access to a set of resource blocks is via a addition, if the access to a set of resource blocks is via a shared
shared fiber (Figure 2) this would impose a dynamic wavelength fiber (Figure 2) this would impose a dynamic wavelength availability
availability constraint on that shared fiber. The resource block constraint on that shared fiber. The resource block input port
ingress port constraint is modeled via a static wavelength set constraint is modeled via a static wavelength set mechanism and the
mechanism and the case of shared access to a set of blocks is modeled case of shared access to a set of blocks is modeled via a dynamic
via a dynamic wavelength set mechanism. wavelength set mechanism.
Next a state vector RA(j) = {0,...,k} is used to track the number of Next a state vector RA(j) = {0,...,k} is used to track the number of
resources in resource block j in use. This is the only state kept in resources in resource block j in use. This is the only state kept in
the resource pool model. This state is not necessary for modeling the resource pool model. This state is not necessary for modeling
"fixed" transponder system or full OEO switches with WDM interfaces, "fixed" transponder system or full OEO switches with WDM interfaces,
i.e., systems where there is no sharing. i.e., systems where there is no sharing.
After that, a set of static resource egress wavelength constraints After that, a set of static resource output wavelength constraints
and possibly dynamic shared egress fiber constraints maybe used. The and possibly dynamic shared output fiber constraints maybe used. The
static constraints indicate what wavelengths a particular resource static constraints indicate what wavelengths a particular resource
block can generate or are restricted to generating e.g., a fixed block can generate or are restricted to generating e.g., a fixed
regenerator would be limited to a single lambda. The dynamic regenerator would be limited to a single lambda. The dynamic
constraints would be used in the case where a single shared fiber is constraints would be used in the case where a single shared fiber is
used to egress the resource block (Figure 2). used to output the resource block (Figure 2).
Finally, to complete the model, a resource pool egress matrix RE(p,k) Finally, to complete the model, a resource pool output matrix RE(p,k)
= {0,1} depending on whether the output from resource block p can = {0,1} depending on whether the output from resource block p can
reach egress port k, may be used. reach output port k, may be used.
I1 +-------------+ +-------------+ E1 I1 +-------------+ +-------------+ E1
----->| | +--------+ | |-----> ----->| | +--------+ | |----->
I2 | +------+ Rb #1 +-------+ | E2 I2 | +------+ Rb #1 +-------+ | E2
----->| | +--------+ | |-----> ----->| | +--------+ | |----->
| | | | | | | |
| Resource | +--------+ | Resource | | Resource | +--------+ | Resource |
| Pool +------+ +-------+ Pool | | Pool +------+ +-------+ Pool |
| | + Rb #2 + | | | | + Rb #2 + | |
| Ingress +------+ +-------| Egress | | Input +------+ +-------| Output |
| Connection | +--------+ | Connection | | Connection | +--------+ | Connection |
| Matrix | . | Matrix | | Matrix | . | Matrix |
| | . | | | | . | |
| | . | | | | . | |
IN | | +--------+ | | EM IN | | +--------+ | | EM
----->| +------+ Rb #P +-------+ |-----> ----->| +------+ Rb #P +-------+ |----->
| | +--------+ | | | | +--------+ | |
+-------------+ ^ ^ +-------------+ +-------------+ ^ ^ +-------------+
| | | |
| | | |
| | | |
| | | |
Ingress wavelength Egress wavelength Input wavelength Output wavelength
constraints for constraints for constraints for constraints for
each resource each resource each resource each resource
Figure 1 Schematic diagram of resource pool model. Figure 1 Schematic diagram of resource pool model.
I1 +-------------+ +-------------+ E1 I1 +-------------+ +-------------+ E1
----->| | +--------+ | |-----> ----->| | +--------+ | |----->
I2 | +======+ Rb #1 +-+ + | E2 I2 | +======+ Rb #1 +-+ + | E2
----->| | +--------+ | | |-----> ----->| | +--------+ | | |----->
| | |=====| | | | |=====| |
| Resource | +--------+ | | Resource | | Resource | +--------+ | | Resource |
| Pool | +-+ Rb #2 +-+ | Pool | | Pool | +-+ Rb #2 +-+ | Pool |
| | | +--------+ + | | | | +--------+ + |
| Ingress |====| | Egress | | Input |====| | Output |
| Connection | | +--------+ | Connection | | Connection | | +--------+ | Connection |
| Matrix | +-| Rb #3 |=======| Matrix | | Matrix | +-| Rb #3 |=======| Matrix |
| | +--------+ | | | | +--------+ | |
| | . | | | | . | |
| | . | | | | . | |
| | . | | | | . | |
IN | | +--------+ | | EM IN | | +--------+ | | EM
----->| +======+ Rb #P +=======+ |-----> ----->| +======+ Rb #P +=======+ |----->
| | +--------+ | | | | +--------+ | |
+-------------+ ^ ^ +-------------+ +-------------+ ^ ^ +-------------+
| | | |
| | | |
| | | |
Single (shared) fibers for block ingress and egress Single (shared) fibers for block input and output
Ingress wavelength Egress wavelength Input wavelength Output wavelength
availability for availability for availability for availability for
each block ingress fiber each block egress fiber each block input fiber each block output fiber
Figure 2 Schematic diagram of resource pool model with shared block Figure 2 Schematic diagram of resource pool model with shared block
accessibility. accessibility.
Formally the model can be specified as: Formally the model can be specified as:
<ResourceBlockAccessibility> ::= <PoolIngressMatrix> <ResourceAccessibility ::= <PoolInputMatrix> <PoolOutputMatrix>
<PoolEgressMatrix>
<ResourceWaveConstraints> ::= <IngressWaveConstraints> [<ResourceWaveConstraints> ::= <InputWaveConstraints>
<EgressWaveConstraints> <OutputOutputWaveConstraints>
<RBPoolState> <RBPoolState>
::=(<ResourceBlockID><NumResourcesInUse><InAvailableWavelengths><OutA ::=(<ResourceBlockID><NumResourcesInUse><InAvailableWavelengths><OutA
vailableWavelengths>)... vailableWavelengths>)...
Note that except for <RBPoolState> all the other components of Note that except for <ResourcePoolState> all the other components of
<ResourcePool> are relatively static. Also the <ResourcePool> are relatively static. Also the
<InAvailableWavelengths> and <OutAvailableWavelengths> are only used <InAvailableWavelengths> and <OutAvailableWavelengths> are only used
in the cases of shared ingress or egress access to the particular in the cases of shared input or output access to the particular
block. See the resource block information in the next section to see block. See the resource block information in the next section to see
how this is specified. how this is specified.
5.2. Resource Signal Constraints and Processing Capabilities 5.2. Resource Signal Constraints and Processing Capabilities
The wavelength conversion abilities of a resource (e.g. regenerator, The wavelength conversion abilities of a resource (e.g. regenerator,
wavelength converter) were modeled in the <EgressWaveConstraints> wavelength converter) were modeled in the <OutputWaveConstraints>
previously discussed. As discussed in [WSON-Frame] the constraints on previously discussed. As discussed in [RFC6163] the constraints on an
an electro-optical resource can be modeled in terms of input electro-optical resource can be modeled in terms of input
constraints, processing capabilities, and output constraints: constraints, processing capabilities, and output constraints:
<ResourceBlockInfo> ::= ([<ResourceSet>] <InputConstraints> <ResourceBlockInfo> ::= ([<ResourceSet>] <InputConstraints>
<ProcessingCapabilities> <OutputConstraints>)* <ProcessingCapabilities> <OutputConstraints>)*
Where <ResourceSet> is a list of resource block identifiers with the Where <ResourceSet> is a list of resource block identifiers with the
same characteristics. If this set is missing the constraints are same characteristics. If this set is missing the constraints are
applied to the entire network element. applied to the entire network element.
The <InputConstraints> are signal compatibility based constraints The <InputConstraints> are signal compatibility based constraints
and/or shared access constraint indication. The details of these and/or shared access constraint indication. The details of these
constraints are defined in section 5.3. constraints are defined in section 5.3.
<InputConstraints> ::= <SharedIngress> <ModulationTypeList> <InputConstraints> ::= <SharedInput> <ModulationTypeList>
<FECTypeList> <BitRateRange> <ClientSignalList> <FECTypeList> <BitRateRange> <ClientSignalList>
The <ProcessingCapabilities> are important operations that the The <ProcessingCapabilities> are important operations that the
resource (or network element) can perform on the signal. The details resource (or network element) can perform on the signal. The details
of these capabilities are defined in section 5.3. of these capabilities are defined in section 5.3.
<ProcessingCapabilities> ::= <NumResources> <ProcessingCapabilities> ::= <NumResources>
<RegenerationCapabilities> <FaultPerfMon> <VendorSpecific> <RegenerationCapabilities> <FaultPerfMon> <VendorSpecific>
The <OutputConstraints> are either restrictions on the properties of The <OutputConstraints> are either restrictions on the properties of
the signal leaving the block, options concerning the signal the signal leaving the block, options concerning the signal
properties when leaving the resource or shared fiber egress properties when leaving the resource or shared fiber output
constraint indication. constraint indication.
<OutputConstraints> ::= <SharedEgress> <ModulationTypeList> <OutputConstraints> := <SharedOutput> <ModulationTypeList>
<FECTypeList> <FECTypeList>
5.3. Compatibility and Capability Details 5.3. Compatibility and Capability Details
5.3.1. Shared Ingress or Egress Indication 5.3.1. Shared Input or Output Indication
As discussed in the previous section and shown in Figure 2 the As discussed in the previous section and shown in Figure 2 the input
ingress or egress access to a resource block may be via a shared or output access to a resource block may be via a shared fiber. The
fiber. The <SharedIngress> and <SharedEgress> elements are indicators <SharedInput> and <SharedOutput> elements are indicators for this
for this condition with respect to the block being described. condition with respect to the block being described.
5.3.2. Modulation Type List 5.3.2. Modulation Type List
Modulation type, also known as optical tributary signal class, Modulation type, also known as optical tributary signal class,
comes in two distinct flavors: (i) ITU-T standardized types; (ii) comes in two distinct flavors: (i) ITU-T standardized types; (ii)
vendor specific types. The permitted modulation type list can vendor specific types. The permitted modulation type list can
include any mixture of standardized and vendor specific types. include any mixture of standardized and vendor specific types.
<modulation-list>::= <modulation-list>::=
[<STANDARD_MODULATION>|<VENDOR_MODULATION>]... [<STANDARD_MODULATION>|<VENDOR_MODULATION>]...
skipping to change at page 19, line 42 skipping to change at page 19, line 42
and have label restrictions. In addition, the types of label and have label restrictions. In addition, the types of label
restrictions that can be supported are extensible. restrictions that can be supported are extensible.
6.6.1. Port-Wavelength Exclusivity Example 6.6.1. Port-Wavelength Exclusivity Example
Although there can be many different ROADM or switch architectures Although there can be many different ROADM or switch architectures
that can lead to the constraint where a lambda (label) maybe used at that can lead to the constraint where a lambda (label) maybe used at
most once on a set of ports Figure 3 shows a ROADM architecture based most once on a set of ports Figure 3 shows a ROADM architecture based
on components known as a Wavelength Selective Switch (WSS)[OFC08]. on components known as a Wavelength Selective Switch (WSS)[OFC08].
This ROADM is composed of splitters, combiners, and WSSes. This ROADM This ROADM is composed of splitters, combiners, and WSSes. This ROADM
has 11 egress ports, which are numbered in the diagram. Egress ports has 11 output ports, which are numbered in the diagram. Output ports
1-8 are known as drop ports and are intended to support a single 1-8 are known as drop ports and are intended to support a single
wavelength. Drop ports 1-4 egress from WSS #2, which is fed from WSS wavelength. Drop ports 1-4 output from WSS #2, which is fed from WSS
#1 via a single fiber. Due to this internal structure a constraint is #1 via a single fiber. Due to this internal structure a constraint is
placed on the egress ports 1-4 that a lambda can be only used once placed on the output ports 1-4 that a lambda can be only used once
over the group of ports (assuming uni-cast and not multi-cast over the group of ports (assuming uni-cast and not multi-cast
operation). Similarly the egress ports 5-8 have a similar constraint operation). Similarly the output ports 5-8 have a similar constraint
due to the internal structure. due to the internal structure.
| A | A
v 10 | v 10 |
+-------+ +-------+ +-------+ +-------+
| Split | |WSS 6 | | Split | |WSS 6 |
+-------+ +-------+ +-------+ +-------+
+----+ | | | | | | | | +----+ | | | | | | | |
| W | | | | | | | | +-------+ +----+ | W | | | | | | | | +-------+ +----+
| S |--------------+ | | | +-----+ | +----+ | | S | | S |--------------+ | | | +-----+ | +----+ | | S |
skipping to change at page 24, line 12 skipping to change at page 24, line 12
[RFC5305] Li, T. and H. Smit, "IS-IS Extensions for Traffic [RFC5305] Li, T. and H. Smit, "IS-IS Extensions for Traffic
Engineering", RFC 5305, October 2008. Engineering", RFC 5305, October 2008.
[RFC5307] Kompella, K., Ed., and Y. Rekhter, Ed., "IS-IS Extensions [RFC5307] Kompella, K., Ed., and Y. Rekhter, Ed., "IS-IS Extensions
in Support of Generalized Multi-Protocol Label Switching in Support of Generalized Multi-Protocol Label Switching
(GMPLS)", RFC 5307, October 2008. (GMPLS)", RFC 5307, October 2008.
11.2. Informative References 11.2. Informative References
[OFC08] P. Roorda and B. Collings, "Evolution to Colorless and [OFC08] P. Roorda and B. Collings, "Evolution to Colorless and
Directionless ROADM Architectures," Optical Fiber Directionless ROADM Architectures," Optical Fiber
communication/National Fiber Optic Engineers Conference, 2008. communication/National Fiber Optic Engineers Conference,
OFC/NFOEC 2008. Conference on, 2008, pp. 1-3. 2008. OFC/NFOEC 2008. Conference on, 2008, pp. 1-3.
[Shared] G. Bernstein, Y. Lee, "Shared Backup Mesh Protection in PCE- [Shared] G. Bernstein, Y. Lee, "Shared Backup Mesh Protection in PCE-
based WSON Networks", iPOP 2008, http://www.grotto- based WSON Networks", iPOP 2008, http://www.grotto-
networking.com/wson/iPOP2008_WSON-shared-mesh-poster.pdf. networking.com/wson/iPOP2008_WSON-shared-mesh-poster.pdf .
[Switch] G. Bernstein, Y. Lee, A. Gavler, J. Martensson, " Modeling [Switch] G. Bernstein, Y. Lee, A. Gavler, J. Martensson, " Modeling
WDM Wavelength Switching Systems for Use in GMPLS and Automated WDM Wavelength Switching Systems for Use in GMPLS and
Path Computation", Journal of Optical Communications and Automated Path Computation", Journal of Optical
Networking, vol. 1, June, 2009, pp. 187-195. Communications and Networking, vol. 1, June, 2009, pp. 187-
195.
[G.Sup39] ITU-T Series G Supplement 39, Optical system design and [G.Sup39] ITU-T Series G Supplement 39, Optical system design and
engineering considerations, February 2006. engineering considerations, February 2006.
[WSON-Frame] Y. Lee, G. Bernstein, W. Imajuku, "Framework for GMPLS [RFC6163] Y. Lee, G. Bernstein, W. Imajuku, "Framework for GMPLS and
and PCE Control of Wavelength Switched Optical Networks", PCE Control of Wavelength Switched Optical Networks", RFC
work in progress: draft-ietf-ccamp-rwa-wson-framework. 6163, April 2011.
12. Contributors 12. Contributors
Diego Caviglia Diego Caviglia
Ericsson Ericsson
Via A. Negrone 1/A 16153 Via A. Negrone 1/A 16153
Genoa Italy Genoa Italy
Phone: +39 010 600 3736 Phone: +39 010 600 3736
Email: diego.caviglia@(marconi.com, ericsson.com) Email: diego.caviglia@(marconi.com, ericsson.com)
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