draft-ietf-ccamp-rwa-info-10.txt   draft-ietf-ccamp-rwa-info-11.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: August 2011 Grotto Networking Expires: September 2011 Grotto Networking
D. Li D. Li
Huawei Huawei
W. Imajuku W. Imajuku
NTT NTT
February 28, 2011 March 14, 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-10.txt draft-ietf-ccamp-rwa-info-11.txt
Status of this Memo Status of this Memo
This Internet-Draft is submitted to IETF in full conformance with the This Internet-Draft is submitted to IETF in full conformance with the
provisions of BCP 78 and BCP 79. provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF), its areas, and its working groups. Note that Task Force (IETF), its areas, and its working groups. Note that
other groups may also distribute working documents as Internet- other groups may also distribute working documents as Internet-
Drafts. Drafts.
skipping to change at page 1, line 39 skipping to change at page 1, line 39
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."
The list of current Internet-Drafts can be accessed at The list of current Internet-Drafts can be accessed at
http://www.ietf.org/ietf/1id-abstracts.txt http://www.ietf.org/ietf/1id-abstracts.txt
The list of Internet-Draft Shadow Directories can be accessed at The list of Internet-Draft Shadow Directories can be accessed at
http://www.ietf.org/shadow.html http://www.ietf.org/shadow.html
This Internet-Draft will expire on August 28, 2011. This Internet-Draft will expire on September 14, 2011.
Copyright Notice Copyright Notice
Copyright (c) 2011 IETF Trust and the persons identified as the Copyright (c) 2011 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of (http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents publication of this document. Please review these documents
skipping to change at page 2, line 20 skipping to change at page 2, line 20
to this document. Code Components extracted from this document must to this document. Code Components extracted from this document must
include Simplified BSD License text as described in Section 4.e of include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License. described in the Simplified BSD License.
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 lightpath computation in in this model is to facilitate constrained optical path computation
WSONs. This model takes into account compatibility constraints in 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......................................4
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
2. Terminology....................................................6 2. Terminology....................................................6
3. Routing and Wavelength Assignment Information Model............6 3. Routing and Wavelength Assignment Information Model............6
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.......................................7 4.1. Connectivity Matrix.......................................8
4.2. Shared Risk Node Group....................................8 4.2. Shared Risk Node Group....................................8
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..13 5.2. Resource Signal Constraints and Processing Capabilities..14
5.3. Compatibility and Capability Details.....................14 5.3. Compatibility and Capability Details.....................15
5.3.1. Shared Ingress or Egress Indication.................14 5.3.1. Shared Ingress or Egress Indication.................15
5.3.2. Modulation Type List................................14 5.3.2. Modulation Type List................................15
5.3.3. FEC Type List.......................................14 5.3.3. FEC Type List.......................................15
5.3.4. Bit Rate Range List.................................14 5.3.4. Bit Rate Range List.................................15
5.3.5. Acceptable Client Signal List.......................15 5.3.5. Acceptable Client Signal List.......................16
5.3.6. Processing Capability List..........................15 5.3.6. Processing Capability List..........................16
6. Link Information (General)....................................15 6. Link Information (General)....................................16
6.1. Administrative Group.....................................16 6.1. Administrative Group.....................................17
6.2. Interface Switching Capability Descriptor................16 6.2. Interface Switching Capability Descriptor................17
6.3. Link Protection Type (for this link).....................16 6.3. Link Protection Type (for this link).....................17
6.4. Shared Risk Link Group Information.......................16 6.4. Shared Risk Link Group Information.......................17
6.5. Traffic Engineering Metric...............................16 6.5. Traffic Engineering Metric...............................17
6.6. Port Label (Wavelength) Restrictions.....................16 6.6. Port Label (Wavelength) Restrictions.....................17
6.6.1. Port-Wavelength Exclusivity Example.................18 6.6.1. Port-Wavelength Exclusivity Example.................19
7. Dynamic Components of the Information Model...................19 7. Dynamic Components of the Information Model...................20
7.1. Dynamic Link Information (General).......................20 7.1. Dynamic Link Information (General).......................21
7.2. Dynamic Node Information (WSON Specific).................20 7.2. Dynamic Node Information (WSON Specific).................21
8. Security Considerations.......................................20 8. Security Considerations.......................................21
9. IANA Considerations...........................................21 9. IANA Considerations...........................................22
10. Acknowledgments..............................................21 10. Acknowledgments..............................................22
11. References...................................................22 11. References...................................................23
11.1. Normative References....................................22 11.1. Normative References....................................23
11.2. Informative References..................................23 11.2. Informative References..................................24
12. Contributors.................................................24 12. Contributors.................................................25
Author's Addresses...............................................24 Author's Addresses...............................................25
Intellectual Property Statement..................................25 Intellectual Property Statement..................................26
Disclaimer of Validity...........................................26 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 lightpath computation and as such is not a facilitate constrained optical path 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 lightpath computation is known as and the corresponding constrained optical path computation is known
the routing and wavelength assignment (RWA) problem. Hence the as 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 [WSON-Frame]. The model defined here
includes constraints between WSON signal attributes and network includes constraints between WSON signal attributes and network
elements, but does not include optical impairments. elements, but 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. We refer to the information model applicable to GMPLS control plane. The portion of the information model applicable
other technologies beyond WSON as "general" to distinguish from the to other technologies beyond WSON is referred to as "general" to
"WSON-specific" model that is applicable only to WSON technology. distinguish it from the "WSON-specific" portion that is applicable
only to WSON technology.
1.1. Revision History 1.1. Revision History
1.1.1. Changes from 01 1.1.1. Changes from 01
Added text on multiple fixed and switched connectivity matrices. Added text on multiple fixed and switched connectivity matrices.
Added text on the relationship between SRNG and SRLG and encoding Added text on the relationship between SRNG and SRLG and encoding
considerations. considerations.
skipping to change at page 5, line 19 skipping to change at page 5, line 21
Removed encoding specific text from Section 3.4. Removed encoding specific text from Section 3.4.
1.1.5. Changes from 05 1.1.5. Changes from 05
Renumbered sections for clarity. Renumbered sections for clarity.
Updated abstract and introduction to encompass signal Updated abstract and introduction to encompass signal
compatibility/generalization. compatibility/generalization.
Generalized Section on wavelength converter pools to include electro Generalized Section on wavelength converter pools to include electro
optical subsystems in general. This is where we added signal optical subsystems in general. This is where signal compatibility
compatibility modeling. modeling was added.
1.1.6. Changes from 06 1.1.6. Changes from 06
Simplified information model for WSON specifics, by combining similar Simplified information model for WSON specifics, by combining similar
fields and introducing simpler aggregate information elements. fields and introducing simpler aggregate information elements.
1.1.7. Changes from 07 1.1.7. Changes from 07
Added shared fiber connectivity to resource pool modeling. This Added shared fiber connectivity to resource pool modeling. This
includes information for determining wavelength collision on an includes information for determining wavelength collision on an
skipping to change at page 6, line 5 skipping to change at page 6, line 5
1.1.9. Changes from 09 1.1.9. Changes from 09
Section 5: clarified the way that the resource pool is modeled from Section 5: clarified the way that the resource pool is modeled from
blocks of identical resources. blocks of identical resources.
Section 5.1: grammar fixes. Removed reference to "academic" modeling Section 5.1: grammar fixes. Removed reference to "academic" modeling
pre-print. Clarified RBNF resource pool model details. pre-print. Clarified RBNF resource pool model details.
Section 5.2: Formatting fixes. Section 5.2: Formatting fixes.
1.1.10. Changes from 10
Enhanced the explanation of shared fiber access to resources and
updated Figure 2 to show a more general situation to be modeled.
Removed all 1st person idioms.
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 ingress and
skipping to change at page 6, line 33 skipping to change at page 6, line 40
process or via a strictly optical process. process or via a strictly optical process.
WDM: Wavelength Division Multiplexing. WDM: Wavelength Division Multiplexing.
Wavelength Switched Optical Network (WSON): A WDM based optical Wavelength Switched Optical Network (WSON): A WDM based optical
network in which switching is performed selectively based on the network in which switching is performed selectively based on the
center wavelength of an optical signal. center wavelength of an optical signal.
3. Routing and Wavelength Assignment Information Model 3. Routing and Wavelength Assignment Information Model
We group the following WSON RWA information model into four The following WSON RWA information model is grouped into four
categories regardless of whether they stem from a switching subsystem categories regardless of whether they stem from a switching subsystem
or from a line subsystem: or from a line subsystem:
o Node Information o Node Information
o Link Information o Link Information
o Dynamic Node Information o Dynamic Node Information
o Dynamic Link Information o Dynamic Link Information
skipping to change at page 6, line 44 skipping to change at page 7, line 4
categories regardless of whether they stem from a switching subsystem categories regardless of whether they stem from a switching subsystem
or from a line subsystem: or from a line subsystem:
o Node Information o Node Information
o Link Information o Link Information
o Dynamic Node Information o Dynamic Node Information
o Dynamic Link Information o Dynamic Link Information
Note that this is roughly the categorization used in [G.7715] section Note that this is roughly the categorization used in [G.7715] section
7. 7.
In the following we use, where applicable, the reduced Backus-Naur In the following, where applicable, the reduced Backus-Naur form
form (RBNF) syntax of [RBNF] to aid in defining the RWA information (RBNF) syntax of [RBNF] is used to aid in defining the RWA
model. information model.
3.1. Dynamic and Relatively Static Information 3.1. Dynamic and Relatively Static Information
All the RWA information of concern in a WSON network is subject to All the RWA information of concern in a WSON network is subject to
change over time. Equipment can be upgraded; links may be placed in change over time. Equipment can be upgraded; links may be placed in
or out of service and the like. However, from the point of view of or out of service and the like. However, from the point of view of
RWA computations there is a difference between information that can RWA computations there is a difference between information that can
change with each successive connection establishment in the network change with each successive connection establishment in the network
and that information that is relatively static on the time scales of and that information that is relatively static on the time scales of
connection establishment. A key example of the former is link connection establishment. A key example of the former is link
wavelength usage since this can change with connection setup/teardown wavelength usage since this can change with connection setup/teardown
and this information is a key input to the RWA process. Examples of and this information is a key input to the RWA process. Examples of
relatively static information are the potential port connectivity of relatively static information are the potential port connectivity of
a WDM ROADM, and the channel spacing on a WDM link. a WDM ROADM, and the channel spacing on a WDM link.
In this document we will separate, where possible, dynamic and static This document separates, where possible, dynamic and static
information so that these can be kept separate in possible encodings information so that these can be kept separate in possible encodings
and hence allowing for separate updates of these two types of and hence allowing for separate updates of these two types of
information thereby reducing processing and traffic load caused by information thereby reducing processing and traffic load caused by
the timely distribution of the more dynamic RWA WSON information. the timely distribution of the more dynamic RWA WSON information.
4. Node Information (General) 4. Node Information (General)
The node information described here contains the relatively static The node information described here contains the relatively static
information related to a WSON node. This includes connectivity information related to a WSON node. This includes connectivity
constraints amongst ports and wavelengths since WSON switches can constraints amongst ports and wavelengths since WSON switches can
exhibit asymmetric switching properties. Additional information could exhibit asymmetric switching properties. Additional information could
include properties of wavelength converters in the node if any are include properties of wavelength converters in the node if any are
present. In [Switch] it was shown that the wavelength connectivity present. In [Switch] it was shown that the wavelength connectivity
constraints for a large class of practical WSON devices can be constraints for a large class of practical WSON devices can be
modeled via switched and fixed connectivity matrices along with modeled via switched and fixed connectivity matrices along with
corresponding switched and fixed port constraints. We include these corresponding switched and fixed port constraints. These connectivity
connectivity matrices with our node information the switched and matrices are included with the node information while the switched
fixed port wavelength constraints with the link information. and fixed port wavelength constraints are included with the link
information.
Formally, Formally,
<Node_Information> ::= <Node_ID> [<ConnectivityMatrix>...] <Node_Information> ::= <Node_ID> [<ConnectivityMatrix>...]
Where the Node_ID would be an appropriate identifier for the node Where the Node_ID would be an appropriate identifier for the node
within the WSON RWA context. within the WSON RWA context.
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
skipping to change at page 8, line 9 skipping to change at page 8, line 19
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 ingress 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 it's 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 ingress ports and N
the number of egress ports. We say this is a "conceptual" matrix the number of egress ports. This is a "conceptual" matrix since the
since this matrix tends to exhibit structure that allows for very matrix tends to exhibit structure that allows for very compact
compact representations that are useful for both transmission and representations that are useful for both transmission and path
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(i, j) ::= <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 ingress port i can connect
skipping to change at page 9, line 21 skipping to change at page 9, line 29
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 [WSON-Frame] this can
include OEO based WDM switches as well. There are a number of include OEO based WDM switches as well. There are a number of
different approaches used in the design of WDM switches containing different approaches used in the design of WDM switches containing
regenerator or converter pools. However, from the point of view of regenerator or converter pools. However, from the point of view of
path computation we need to know the following: path 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 ingress wavelength on a particular ingress
port to a desired egress wavelength on a particular egress port. port to a desired egress wavelength on a particular egress 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 we group identical For modeling purposes and encoding efficiency identical processing
processing resources such as regenerators or wavelength converters resources such as regenerators or wavelength converters with
with identical accessibility properties into "blocks". The resource identical limitations, and processing and accessibility properties
pool model is composed of one or more resource blocks where the are grouped into "blocks". Such blocks can consist of a single
accessibility to and from any resource within a block is the same. resource, though grouping resources into blocks leads to more
efficient encodings. The resource pool model is composed of one or
more resource blocks where the accessibility to and from any resource
within a block is the same.
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>...] [<ResourceBlockAccessibility>...] [<ResourceWaveConstraints>...]
[<RBPoolState>] [<RBPoolState>]
First we will address the accessibility of resource blocks then we First the accessibility of resource blocks is addressed then their
will discuss their properties. 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 [WSON-Frame] 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 we will also want to our model to considered a scarce resource it is desirable that the model include,
include as a minimum the usage state (availability) of individual if desired, the usage state (availability) of individual regenerators
regenerators or converters in the pool. Models that incorporate more or converters in the pool. Models that incorporate more state to
state to further reveal blocking conditions on ingress or egress to further reveal blocking conditions on ingress or egress to particular
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 in Figure 1 we 2. The difference between the two figures is that Figure 1 assumes
assume that each signal that can get to a resource block may do so, that each signal that can get to a resource block may do so, while in
while in Figure 2 the access to the resource blocks is via a shared Figure 2 the access to sets of resource blocks is via a shared fiber
fiber which imposes its own wavelength collision constraint. In the which imposes its own wavelength collision constraint. The
representation of Figure 1 we can have more than one ingress to each representation of Figure 1 can have more than one ingress to each
resource block since each ingress represents a single wavelength resource block since each ingress represents a single wavelength
signal, while in Figure 2 we show a single multiplexed WDM ingress, signal, while in Figure 2 shows a single multiplexed WDM ingress or
e.g., a fiber, to each block. egress, e.g., a fiber, to/from each set of block.
In this model we assume N ingress ports (fibers), P resource blocks This model assumes N ingress 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 egress ports (fibers). Since not all ingress 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 ingress matrix RI(i,p) = {0,1} whether ingress port i
can reach potentially reach resource block p. can 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 we have a set the resources may have limited input wavelength range the model has a
of relatively static ingress port constraints for each resource. In set of relatively static ingress port constraints for each resource.
addition, if the access to a resource block is via a shared fiber In addition, if the access to a set of resource blocks is via a
(Figure 2) this would impose a dynamic wavelength availability shared fiber (Figure 2) this would impose a dynamic wavelength
constraint on that shared fiber. We can model each resource block availability constraint on that shared fiber. The resource block
ingress port constraint via a static wavelength set mechanism and in ingress port constraint is modeled via a static wavelength set
the case of shared access to a block via another dynamic wavelength mechanism and the case of shared access to a set of blocks is modeled
set mechanism. via a dynamic wavelength set mechanism.
Next we have a state vector RA(j) = {0,...,k} which tells us the Next a state vector RA(j) = {0,...,k} is used to track the number of
number of resources in resource block j in use. This is the only resources in resource block j in use. This is the only state kept in
state kept in the resource pool model. This state is not necessary the resource pool model. This state is not necessary for modeling
for modeling "fixed" transponder system or full OEO switches with WDM "fixed" transponder system or full OEO switches with WDM interfaces,
interfaces, i.e., systems where there is no sharing. i.e., systems where there is no sharing.
After that, we have a set of static resource egress wavelength After that, a set of static resource egress wavelength constraints
constraints and possibly dynamic shared egress fiber constraints. The and possibly dynamic shared egress 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 egress the resource block (Figure 2).
Finally, we have a resource pool egress matrix RE(p,k) = {0,1} Finally, to complete the model, a resource pool egress matrix RE(p,k)
depending on whether the output from resource block p can reach = {0,1} depending on whether the output from resource block p can
egress port k. reach egress 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 | | Ingress +------+ +-------| Egress |
skipping to change at page 12, line 5 skipping to change at page 13, line 5
| | | |
| | | |
| | | |
Ingress wavelength Egress wavelength Ingress wavelength Egress 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 | | | | Pool | | Pool | +-+ Rb #2 +-+ | Pool |
| |======+ Rb #2 +=======+ | | | | +--------+ + |
| Ingress | + | | Egress | | Ingress |====| | Egress |
| Connection | +--------+ | Connection | | Connection | | +--------+ | Connection |
| Matrix | . | Matrix | | Matrix | +-| Rb #3 |=======| Matrix |
| | . | | | | +--------+ | |
| | . | | | | . | |
IN | | +--------+ | | EM | | . | |
----->| +======+ Rb #P +=======+ |-----> | | . | |
| | +--------+ | | IN | | +--------+ | | EM
+-------------+ ^ ^ +-------------+ ----->| +======+ Rb #P +=======+ |----->
| | | | +--------+ | |
| | +-------------+ ^ ^ +-------------+
| | | |
Single (shared) fibers for block ingress and egress | |
| |
Single (shared) fibers for block ingress and egress
Ingress wavelength Egress wavelength Ingress wavelength Egress wavelength
availability for availability for availability for availability for
each block ingress fiber each block egress fiber each block ingress fiber each block egress 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 we complete the specification of the model with: Formally the model can be specified as:
<ResourceBlockAccessibility ::= <PoolIngressMatrix> <ResourceBlockAccessibility> ::= <PoolIngressMatrix>
<PoolEgressMatrix> <PoolEgressMatrix>
[<ResourceWaveConstraints> ::= <IngressWaveConstraints> <ResourceWaveConstraints> ::= <IngressWaveConstraints>
<EgressWaveConstraints> <EgressWaveConstraints>
<RBPoolState> <RBPoolState>
::=(<ResourceBlockID><NumResourcesInUse><InAvailableWavelengths><OutA ::=(<ResourceBlockID><NumResourcesInUse><InAvailableWavelengths><OutA
vailableWavelengths>)... vailableWavelengths>)...
Note that except for <ResourcePoolState> all the other components of Note that except for <RBPoolState> 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 ingress or egress 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 <EgressWaveConstraints>
previously discussed. As discussed in [WSON-Frame] we can model the previously discussed. As discussed in [WSON-Frame] the constraints on
constraints on an electro-optical resource in terms of input an 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
skipping to change at page 13, line 46 skipping to change at page 14, line 46
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 egress
constraint indication. constraint indication.
<OutputConstraints> := <SharedEgress> <ModulationTypeList> <OutputConstraints> ::= <SharedEgress> <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 Ingress or Egress 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
ingress or egress access to a resource block may be via a shared ingress or egress access to a resource block may be via a shared
fiber. The <SharedIngress> and <SharedEgress> elements are indicators fiber. The <SharedIngress> and <SharedEgress> elements are indicators
for this condition with respect to the block being described. for this condition with respect to the block being described.
skipping to change at page 15, line 17 skipping to change at page 16, line 17
The list is simply: The list is simply:
<client-signal-list>::=[<GPID>]... <client-signal-list>::=[<GPID>]...
Where the Generalized Protocol Identifiers (GPID) object Where the Generalized Protocol Identifiers (GPID) object
represents one of the IETF standardized GPID values as defined in represents one of the IETF standardized GPID values as defined in
[RFC3471] and [RFC4328]. [RFC3471] and [RFC4328].
5.3.6. Processing Capability List 5.3.6. Processing Capability List
We have defined ProcessingCapabilities in Section 5.2 as follows: The ProcessingCapabilities were defined in Section 5.2 as follows:
<ProcessingCapabilities> ::= <NumResources> <ProcessingCapabilities> ::= <NumResources>
<RegenerationCapabilities> <FaultPerfMon> <VendorSpecific> <RegenerationCapabilities> <FaultPerfMon> <VendorSpecific>
The processing capability list sub-TLV is a list of processing The processing capability list sub-TLV is a list of processing
functions that the WSON network element (NE) can perform on the functions that the WSON network element (NE) can perform on the
signal including: signal including:
1. Number of Resources within the block 1. Number of Resources within the block
skipping to change at page 18, line 22 skipping to change at page 19, line 23
LabelSet is a conceptual set of labels (wavelengths). LabelSet is a conceptual set of labels (wavelengths).
MaxNumChannels is the maximum number of channels that can be MaxNumChannels is the maximum number of channels that can be
simultaneously used (relative to either a port or a matrix). simultaneously used (relative to either a port or a matrix).
MaxWaveBandWidth is the maximum width of a tunable waveband MaxWaveBandWidth is the maximum width of a tunable waveband
switching device. switching device.
PortSet is a conceptual set of ports. PortSet is a conceptual set of ports.
For example, if the port is a "colored" drop port of a ROADM then we For example, if the port is a "colored" drop port of a ROADM then
have two restrictions: (a) CHANNEL_COUNT, with MaxNumChannels = 1, there are two restrictions: (a) CHANNEL_COUNT, with MaxNumChannels =
and (b) SIMPLE_WAVELENGTH, with the wavelength set consisting of a 1, and (b) SIMPLE_WAVELENGTH, with the wavelength set consisting of a
single member corresponding to the frequency of the permitted single member corresponding to the frequency of the permitted
wavelength. See [Switch] for a complete waveband example. wavelength. See [Switch] for a complete waveband example.
This information model for port wavelength (label) restrictions is This information model for port wavelength (label) restrictions is
fairly general in that it can be applied to ports that have label fairly general in that it can be applied to ports that have label
restrictions only or to ports that are part of an asymmetric switch restrictions only or to ports that are part of an asymmetric switch
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
skipping to change at page 18, line 47 skipping to change at page 19, line 48
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 egress ports, which are numbered in the diagram. Egress 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 egress 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 egress 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 we see that egress ports 5-8 have a similar operation). Similarly the egress ports 5-8 have a similar constraint
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 |
9 | S |----------------|---|----|-------|------|----|---| p | 9 | S |----------------|---|----|-------|------|----|---| p |
skipping to change at page 20, line 9 skipping to change at page 21, line 9
change with subsequent establishment and teardown of connections. change with subsequent establishment and teardown of connections.
Depending on the protocol used to convey this overall information Depending on the protocol used to convey this overall information
model it may be possible to send this dynamic information separate model it may be possible to send this dynamic information separate
from the relatively larger amount of static information needed to from the relatively larger amount of static information needed to
characterize WSON's and their network elements. characterize WSON's and their network elements.
7.1. Dynamic Link Information (General) 7.1. Dynamic Link Information (General)
For WSON links wavelength availability and wavelengths in use for For WSON links wavelength availability and wavelengths in use for
shared backup purposes can be considered dynamic information and shared backup purposes can be considered dynamic information and
hence we can isolate the dynamic information in the following set: hence are grouped with the dynamic information in the following set:
<DynamicLinkInfo> ::= <LinkID> <AvailableLabels> <DynamicLinkInfo> ::= <LinkID> <AvailableLabels>
[<SharedBackupLabels>] [<SharedBackupLabels>]
AvailableLabels is a set of labels (wavelengths) currently available AvailableLabels is a set of labels (wavelengths) currently available
on the link. Given this information and the port wavelength on the link. Given this information and the port wavelength
restrictions we can also determine which wavelengths are currently in restrictions one can also determine which wavelengths are currently
use. This parameter could potential be used with other technologies in use. This parameter could potential be used with other
that GMPLS currently covers or may cover in the future. technologies that GMPLS currently covers or may cover in the future.
SharedBackupLabels is a set of labels (wavelengths) currently used SharedBackupLabels is a set of labels (wavelengths) currently used
for shared backup protection on the link. An example usage of this for shared backup protection on the link. An example usage of this
information in a WSON setting is given in [Shared]. This parameter information in a WSON setting is given in [Shared]. This parameter
could potential be used with other technologies that GMPLS currently could potential be used with other technologies that GMPLS currently
covers or may cover in the future. covers or may cover in the future.
7.2. Dynamic Node Information (WSON Specific) 7.2. Dynamic Node Information (WSON Specific)
Currently the only node information that can be considered dynamic is Currently the only node information that can be considered dynamic is
skipping to change at page 23, line 9 skipping to change at page 24, line 9
Switching (GMPLS) Signaling Extensions for G.709 Optical Switching (GMPLS) Signaling Extensions for G.709 Optical
Transport Networks Control", RFC 4328, January 2006. Transport Networks Control", RFC 4328, January 2006.
[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.
[WSON-Frame] Y. Lee, G. Bernstein, W. Imajuku, "Framework for GMPLS
and PCE Control of Wavelength Switched Optical Networks",
work in progress: draft-ietf-ccamp-rwa-wson-framework.
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, 2008.
OFC/NFOEC 2008. Conference on, 2008, pp. 1-3. 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 Automated
Path Computation", Journal of Optical Communications and Path Computation", Journal of Optical Communications and
Networking, vol. 1, June, 2009, pp. 187-195. 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
and PCE Control of Wavelength Switched Optical Networks",
work in progress: draft-ietf-ccamp-rwa-wson-framework.
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)
 End of changes. 49 change blocks. 
145 lines changed or deleted 158 lines changed or added

This html diff was produced by rfcdiff 1.41. The latest version is available from http://tools.ietf.org/tools/rfcdiff/