PCE Working Group Y. Lee (Editor)
Internet Draft H. Zheng
Intended status: Standard Track Huawei
Expires: June 19, 2019
R. Casellas
R. Vilalta
CTTC
D. Ceccarelli
F. Lazzeri
Ericsson
February 20, 2019
PCEP Extension for Flexible Grid Networks
draft-ietf-pce-flexible-grid-00
Abstract
This document provides the Path Computation Element Communication
Protocol (PCEP) extensions for the support of Routing and Spectrum
Assignment (RSA) in Flexible Grid networks.
Status of this Memo
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This Internet-Draft will expire on June 19, 2019.
Copyright Notice
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Table of Contents
1. Terminology....................................................3
2. Requirements Language..........................................3
3. Introduction...................................................3
4. Spectrum Assignment (SA) Object................................4
4.1. Frequency-Slot Selection TLV..............................6
4.2. Frequency-slot Restriction Constraint TLV.................8
4.2.1. Frequency-Slot Restriction Field....................10
5. Encoding of a RSA Path Reply..................................10
5.1. Error Indicator..........................................11
5.2. NO-PATH Indicator........................................12
6. Manageability Considerations..................................12
6.1. Control of Function and Policy...........................13
6.2. Information and Data Models..............................13
6.3. Verifying Correct Operation..............................13
6.4. Requirements on Other Protocols and Functional Components13
6.5. Impact on Network Operation..............................14
7. Security Considerations.......................................14
8. IANA Considerations...........................................14
8.1. New PCEP Object..........................................14
8.2. New PCEP TLV: Frequency Slot Selection TLV...............15
8.3. New PCEP TLV: Frequency Slot Restriction Constraint TLV..15
8.4. New PCEP TLV: Spectrum Allocation TLV....................15
8.5. New No-Path Reasons......................................16
8.6. New Error-Types and Error-Values.........................16
9. References....................................................17
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9.1. Informative References...................................17
9.2. Normative References.....................................18
10. Contributors.................................................19
Authors' Addresses...............................................20
1. Terminology
This document uses the terminology defined in [RFC4655], [RFC5440]
and [RFC7698].
2. Requirements Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in [RFC2119].
3. Introduction
[RFC4655] defines a PCE based path computation architecture and
explains how a Path Computation Element (PCE) may compute Label
Switched Paths (LSP) in Multiprotocol Label Switching Traffic
Engineering (MPLS-TE) and Generalized MPLS (GMPLS) networks at the
request of Path Computation Clients (PCCs). A PCC is said to be any
network component that makes such a request and may be, for
instance, an Optical Switching Element within a Wavelength Division
Multiplexing (WDM) network. The PCE, itself, can be located
anywhere within the network, and may be within an optical switching
element, a Network Management System (NMS) or Operational Support
System (OSS), or may be an independent network server.
The PCE communications Protocol (PCEP) is the communication protocol
used between a PCC and a PCE, and may also be used between
cooperating PCEs. [RFC4657] sets out the common protocol
requirements for PCEP. Additional application-specific requirements
for PCEP are deferred to separate documents.
[PCEP-WSON] provides the PCEP extensions for the support of Routing
and Wavelength Assignment (RWA) in Wavelength Switched Optical
Networks (WSON) based on the requirements specified in [RFC6163] and
[RFC7449].
[RFC7698] provides Framework and Requirements for GMPLS-Based
Control of Flexi-Grid Dense Wavelength Division Multiplexing (DWDM)
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Networks. To allow efficient allocation of optical spectral
bandwidth for systems that have high bit-rates, the International
Telecommunication Union Telecommunication Standardization Sector
(ITU-T) has extended its Recommendations G.694.1 and G.872 to
include a new Dense Wavelength Division Multiplexing (DWDM) grid by
defining a set of nominal central frequencies, channel spacings, and
the concept of the "frequency slot". In such an environment, a data-
plane connection is switched based on allocated, variable-sized
frequency ranges within the optical spectrum, creating what is known
as a flexible grid (flexi-grid).
This document provides PCEP extensions to support Routing and
Spectrum Assignment (RSA) in in Spectrum Switched Optical Networks
(SSON)[RFC7698].
Figure 2 shows one typical PCE based implementation, which is
referred to as the Combined Routing and Spectrum Assignment (R&SA)
[RFC7698]. With this architecture, the two processes of routing and
spectrum assignment are accessed via a single PCE. This architecture
is the base architecture from which the PCEP extensions are going to
be specified in this document.
+----------------------------+
+-----+ | +-------+ +--+ |
| | | |Routing| |SA| |
| PCC |<----->| +-------+ +--+ |
| | | |
+-----+ | PCE |
+----------------------------+
Figure 1 Combined Process (R&SA) architecture
4. Spectrum Assignment (SA) Object
Spectrum allocation can be performed by the PCE by different means:
(a) By means of Explicit Label Control (ELC) where the PCE
allocates which label to use for each interface/node along the
path.
(b) By means of a Label Set where the PCE provides a range of
potential frequency slots to allocate by each node along the path.
This document aligns with GMPLS extensions for PCEP [PCEP-GMPLS]
for generic property such as label, label-set and label assignment
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noting that frequency is a type of label. Frequency restrictions
and constraints are also formulated in terms of labels per
[RFC7579].
Option (b) allows distributed spectrum allocation (performed during
signaling) to complete spectrum assignment.
Additionally, given a range of potential spectrums to allocate, the
request SHOULD convey the heuristic / mechanism to the allocation.
The format of a PCReq message after incorporating the Spectrum
Assignment (SA) object is as follows:
<PCReq Message> ::= <Common Header>
[<svec-list>]
<request-list>
Where:
<request-list>::=<request>[<request-list>]
<request>::= <RP>
<GENERALIZED ENDPOINTS>
[ <SA> ]
[other optional objects...]
If the SA object is present in the request, it MUST be encoded after
the ENDPOINTS object.
The format of the Spectrum Assignment (SA) object body is as
follows:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Reserved | Flags |M|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Frequency-Slot Selection TLV |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Frequency-Slot Restriction Constraint TLV |
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. .
. .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
// Optional TLVs //
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 2 SA Object
o Reserved (16 bits)
o Flags (16 bits)
The following new flags SHOULD be set
. M (Mode - 1 bit): M bit is used to indicate the mode of
spectrum assignment. When M bit is set to 1, this indicates
that the spectrum assigned by the PCE must be explicit. That
is, the selected way to convey the allocated spectrum is by
means of Explicit Label Control (ELC) [RFC4003] for each hop of
a computed LSP. Otherwise, the spectrum assigned by the PCE
needs not be explicit (i.e., it can be suggested in the form of
label set objects in the corresponding response, to allow
distributed SA. In such case, the PCE MUST return a Label Set
Field as described in Section 2.6 of [RFC7579] in the response.
See Section 5 of this document for the encoding discussion of a
Label Set Field in a PCRep message.
4.1. Frequency-Slot Selection TLV
The Frequency-Slot Selection TLV is used to indicate the frequency-
slot selection constraint in regard to the order of frequency-slot
assignment to be returned by the PCE. This TLV is only applied when
M bit is set in the SA Object specified in Section 3.1. This TLV
MUST NOT be used when the M bit is cleared.
The Frequency-Slot Selection sub-TLV value field is defined as:
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0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|S| FSA Method | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Where:
S (Symmetry, 1 bit): This flag is only meaningful when the
request is for a bidirectional LSP (see [RFC5440]).
0 denotes requiring the same frequency-slot in both directions;
1 denotes that different spectrums on both directions are
allowed.
Frequency-Slot Assignment (FSA) Method (7 bits):
0: unspecified (any); This does not constrain the SA method
used by a PCC This value is implied when the
Frequency-Slot Selection sub-TLV is absent.
1: First-Fit. All the feasible frequency slots are numbered
(based on "n" parameter), and this SA method chooses the
available frequency-slot with the lowest index (of "n"
parameter).
2: Random. This SA method chooses an feasible frequency-slot
("n" paramerer) randomly.
3-127: Unassigned.
The processing rules for this TLV are as follows:
If a PCE does not support the attribute(s), its
behavior is specified below:
- S bit not supported: a PathErr MUST be generated with the
Error Code "Routing Problem" (24) with error sub-code
"Unsupported Frequency slot Selection Symmetry value" (TDB).
- FSA method not supported: a PathErr MUST be generated with the
Error Code "Routing Problem" (24) with error sub-code
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"Unsupported Frequency Slot Assignment value" (TDB).
A Frequency Slot Selection TLV can be constructed by a node and
added to an ERO Hop Attributes subobject in order to be processed
by downstream nodes (transit and egress). As defined in
[RFC7570], the R bit reflects the LSP_REQUIRED_ATTRIBUTE and
LSP_ATTRIBUTE semantic defined in [RFC5420], and it SHOULD be set
accordingly.
Once a node properly parses the Spectrum Selection sub-TLV
received in an ERO Hop Attributes subobject, the node use the
indicated spectrum assignment method (at that hop) for the LSP.
In addition, the node SHOULD report compliance by adding an RRO
Hop Attributes subobject with the WSON Processing Hop Attribute
TLV (and its sub-TLVs) that indicate the utilized method.
Frequency-Slot Selection TLVs carried in an RRO Hop Attributes
subobject are subject to [RFC7570] and standard RRO processing;
see [RFC3209].
4.2. Frequency-slot Restriction Constraint TLV
For any request that contains a Frequency-slot assignment, the
requester (PCC) MUST be able to specify a restriction on the
frequency-slots to be used. This restriction is to be interpreted by
the PCE as a constraint on the tuning ability of the origination
laser transmitter or on any other maintenance related constraints.
The format of the Frequency-Slot Restriction Constraint TLV is as
follows:
<Frequency-lot Restriction Constraint> ::=
<Action> <Count> <Reserved>
(<Link Identifiers> <Freq-slot Restriction>)...
Where
<Link Identifiers> ::= <Link Identifier> [<Link Identifiers>]
See Section 4.3.1 in [PCEP-WSON] for the encoding of the Link
Identifiers Field.
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The Frequency slot Restriction Constraint TLV type is TBD. This TLV
MAY appear more than once to be able to specify multiple
restrictions.
The TLV data is defined as follows:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Action | Count | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Link Identifiers |
| . . . |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Frequency Slot Restriction Field |
// . . . . //
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 3 spectrum Restriction Constraint TLV Encoding
o Action: 8 bits
. 0 - Inclusive List indicates that one or more link identifiers
are included in the Link Set. Each identifies a separate link
that is part of the set.
. 1 - Inclusive Range indicates that the Link Set defines a
range of links. It contains two link identifiers. The first
identifier indicates the start of the range (inclusive). The
second identifier indicates the end of the range (inclusive).
All links with numeric values between the bounds are
considered to be part of the set. A value of zero in either
position indicates that there is no bound on the corresponding
portion of the range. Note that the Action field can be set to
0 when unnumbered link identifier is used.
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o Count: The number of the link identifiers (8 bits)
Note that a PCC MAY add a spectrum restriction that applies to all
links by setting the Count field to zero and specifying just a set
of spectrums.
Note that all link identifiers in the same list must be of the same
type.
o Reserved: Reserved for future use (16 bits)
o Link Identifiers: Identifies each link ID for which restriction
is applied. The length is dependent on the link format and the Count
field. See Section 4.3.1 in [PCEP-WSON] for Link Identifier encoding
and Section 3.3.1 for the Spectrum Restriction Field encoding,
respectively.
4.2.1. Frequency-Slot Restriction Field
The Frequency-Slot Restriction Field of the Frequency slot
restriction TLV is encoded as defined in
https://tools.ietf.org/html/draft-ietf-ccamp-flexible-grid-ospf-ext-
09#section-4.1.1.
5. Encoding of a RSA Path Reply
This section provides the encoding of a RSA Path Reply for frequency
slot allocation as discussed in Section 4. Spectrum Allocation TLV
The Spectrum Allocation TLV type is TBD, recommended value is TBD.
The TLV data is defined as follows:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length |M|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Link Identifier |
| . . . |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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| Allocated Spectrum(s) |
// . . . . //
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 4 Spectrum Allocation TLV Encoding
o Type (16 bits): The type of the TLV.
o Length (15 bits): The length of the TLV including the Type and
Length fields.
o M (Mode): 1 bit
- 0 indicates the allocation is under Explicit Label Control.
- 1 indicates the allocation is expressed in Label Sets.
Note that all link identifiers in the same list must be of the same
type.
o Link Identifier (variable): Identifies the interface to which
assignment spectrum(s) is applied. See Section 3.3 for Link
Identifier encoding.
o Allocated Spectrum(s) (variable): Indicates the allocated
spectrum(s) to the link identifier. See Section 3.3.1 for encoding
details.
This TLV is encoded as an attributes TLV, per [RFC5420], which is
carried in the ERO LSP Attribute Subobjects per [RFC7570]. The type
value of the Spectrum Restriction Constraint TLV is TBD by IANA.
5.1. Error Indicator
To indicate errors associated with the RSA request, a new Error Type
(TDB) and subsequent error-values are defined as follows for
inclusion in the PCEP-ERROR Object:
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A new Error-Type (TDB) and subsequent error-values are defined as
follows:
. Error-Type=TBD; Error-value=1: if a PCE receives a RSA request
and the PCE is not capable of processing the request due to
insufficient memory, the PCE MUST send a PCErr message with a
PCEP-ERROR Object (Error-Type=TDB) and an Error-value(Error-
value=1). The PCE stops processing the request. The
corresponding RSA request MUST be cancelled at the PCC.
. Error-Type=TBD; Error-value=2: if a PCE receives a RSA request
and the PCE is not capable of RSA computation, the PCE MUST
send a PCErr message with a PCEP-ERROR Object (Error-Type=TDB)
and an Error-value (Error-value=2). The PCE stops processing
the request. The corresponding RSA computation MUST be
cancelled at the PCC.
5.2. NO-PATH Indicator
To communicate the reason(s) for not being able to find RSA for the
path request, the NO-PATH object can be used in the corresponding
response. The format of the NO-PATH object body is defined in
[RFC5440]. The object may contain a NO-PATH-VECTOR TLV to provide
additional information about why a path computation has failed.
One new bit flag is defined to be carried in the Flags field in the
NO-PATH-VECTOR TLV carried in the NO-PATH Object.
. Bit TDB: When set, the PCE indicates no feasible route was
found that meets all the constraints (e.g., spectrum
restriction, etc.) associated with RSA.
6. Manageability Considerations
Manageability of SSON Routing and Spectrum Assignment (RSA) with PCE
must address the following considerations:
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6.1. Control of Function and Policy
In addition to the parameters already listed in Section 8.1 of
[RFC5440], a PCEP implementation SHOULD allow configuring the
following PCEP session parameters on a PCC:
. The ability to send a Flexi-Grid RSA request.
In addition to the parameters already listed in Section 8.1 of
[RFC5440], a PCEP implementation SHOULD allow configuring the
following PCEP session parameters on a PCE:
. The support for Flexi-Grid RSA .
. A set of Flexi-Grid RSA specific policies (authorized sender,
request rate limiter, etc).
These parameters may be configured as default parameters for any
PCEP session the PCEP speaker participates in, or may apply to a
specific session with a given PCEP peer or a specific group of
sessions with a specific group of PCEP peers.
6.2. Information and Data Models
Extensions to the PCEP YANG module may include to cover the Flexi-
Grid RSA information introduced in this document. Liveness Detection
and Monitoring
Mechanisms defined in this document do not imply any new liveness
detection and monitoring requirements in addition to those already
listed in section 8.3 of [RFC5440].
6.3. Verifying Correct Operation
Mechanisms defined in this document do not imply any new
verification requirements in addition to those already listed in
section 8.4 of [RFC5440]
6.4. Requirements on Other Protocols and Functional Components
The PCE Discovery mechanisms ([RFC5089] and [RFC5088]) may be used
to advertise Flexi-Grid RSA path computation capabilities to PCCs.
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This draft has requirements on other protocols (ERO objects, etc.
which are under TEAS or CCAMP.)
6.5. Impact on Network Operation
Mechanisms defined in this document do not imply any new network
operation requirements in addition to those already listed in
section 8.6 of [RFC5440].
7. Security Considerations
This document has no requirement for a change to the security models
within PCEP. However, the additional information distributed in
order to address the RSA problem represents a disclosure of network
capabilities that an operator may wish to keep private.
Consideration should be given to securing this information.
8. IANA Considerations
IANA maintains a registry of PCEP parameters. IANA has made
allocations from the sub-registries as described in the following
sections.
8.1. New PCEP Object
As described in Section 4.1, a new PCEP Object is defined to carry
frequency-slot assignment related constraints. IANA is to allocate
the following from "PCEP Objects" sub-registry
(http://www.iana.org/assignments/pcep/pcep.xhtml#pcep-objects):
Object Class Name Object Reference
Value Type
---------------------------------------------------------
TDB SA 1: Spectrum Assignment [This.I-D]
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8.2. New PCEP TLV: Frequency Slot Selection TLV
As described in Sections 4.2, a new PCEP TLV is defined to indicate
spectrum selection constraints. IANA is to allocate this new TLV
from the "PCEP TLV Type Indicators" subregistry
(http://www.iana.org/assignments/pcep/pcep.xhtml#pcep-tlv-type-
indicators).
Value Description Reference
---------------------------------------------------------
TBD Spectrum Selection [This.I-D]
8.3. New PCEP TLV: Frequency Slot Restriction Constraint TLV
As described in Section 4.3, a new PCEP TLV is defined to indicate
wavelength restriction constraints. IANA is to allocate this new TLV
from the "PCEP TLV Type Indicators" subregistry
(http://www.iana.org/assignments/pcep/pcep.xhtml#pcep-tlv-type-
indicators).
Value Description Reference
---------------------------------------------------------
TBD Frequency Slot Restriction [This.I-D]
Constraint
8.4. New PCEP TLV: Spectrum Allocation TLV
As described in Section 5, a new PCEP TLV is defined to indicate the
allocation of freq-slots(s) by the PCE in response to a request by
the PCC. IANA is to allocate this new TLV from the "PCEP TLV Type
Indicators" subregistry
(http://www.iana.org/assignments/pcep/pcep.xhtml#pcep-tlv-type-
indicators).
Value Description Reference
---------------------------------------------------------
TBD Spectrum Allocation [This.I-D]
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8.5. New No-Path Reasons
As described in Section 4.3, a new bit flag are defined to be
carried in the Flags field in the NO-PATH-VECTOR TLV carried in the
NO-PATH Object. This flag, when set, indicates that no feasible
route was found that meets all the RSA constraints (e.g., spectrum
restriction, signal compatibility, etc.) associated with a RSA path
computation request.
IANA is to allocate this new bit flag from the "PCEP NO-PATH-VECTOR
TLV Flag Field" subregistry
(http://www.iana.org/assignments/pcep/pcep.xhtml#no-path-vector-
tlv).
Bit Description Reference
-----------------------------------------------------
TBD No RSA constraints met [This.I-D]
8.6. New Error-Types and Error-Values
As described in Section 5.1, new PCEP error codes are defined for
WSON RWA errors. IANA is to allocate from the ""PCEP-ERROR Object
Error Types and Values" sub-registry
(http://www.iana.org/assignments/pcep/pcep.xhtml#pcep-error-object).
Error- Meaning Error-Value Reference
Type
---------------------------------------------------------------
TDB Flexi-Grid RSA Error 1: Insufficient [This.I-D]
Memory
2: RSA computation [This.I-D]
Not supported
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9. References
9.1. Informative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC2863] McCloghrie, K. and F. Kastenholz, "The Interfaces Group
MIB", RFC 2863, June 2000.
[RFC4003] Berger, L., "GMPLS Signaling Procedure for Egress
Control", RFC 4003, February 2005.
[RFC4655] Farrel, A., Vasseur, J., and J. Ash, "A Path Computation
Element (PCE)-Based Architecture", RFC 4655, August 2006.
[RFC4657] Ash, J. and J. Le Roux, "Path Computation Element (PCE)
Communication Protocol Generic Requirements", RFC 4657,
September 2006.
[RFC5440] Vasseur, JP., Ed. and JL. Le Roux, Ed., "Path Computation
Element (PCE) communication Protocol", RFC 5440, March
2009.
[RFC5088] Le Roux, JL, JP. Vasseur, Y. Ikejiri, and R. Zhang, "OSPF
Protocol Extensions for Path Computation Element (PCE)
Discovery," RFC 5088, January 2008.
[RFC5089] Le Roux, JL, JP. Vasseur, Y. Ikejiri, and R. Zhang, "IS-IS
Protocol Extensions for Path Computation Element (PCE)
Discovery," RFC 5089, January 2008.
[RFC6163] Lee, Y. and Bernstein, G. (Editors), and W. Imajuku,
"Framework for GMPLS and PCE Control of Wavelength
Switched Optical Networks", RFC 6163, March 2011.
[RFC6566] Y. Lee, G. Bernstein, D. Li, G. Martinelli, "A Framework
for the Control of Wavelength Switched Optical Networks
(WSON) with Impairments", RFC 6566, March 2012.
[RFC7420] Koushik, A., E. Stephan, Q. Zhao, D. King, and J.
Hardwick, "Path Computation Element Communication Protocol
(PCEP) Management Information Base (MIB) Module", RFC
7420, December 2014.
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[RFC7446] Y. Lee, G. Bernstein. (Editors), "Routing and Wavelength
Assignment Information Model for Wavelength Switched
Optical Networks", RFC 7446, February 2015.
[RFC7449] Lee, Y., et. al., "PCEP Requirements for WSON Routing and
Wavelength Assignment", RFC 7449, February 2015.
9.2. Normative References
[PCEP-GMPLS] Margaria, et al., "PCEP extensions for GMPLS", draft-
ietf-pce-gmpls-pcep-extensions, work in progress.
[RFC5420] Farrel, A. "Encoding of Attributes for MPLS LSP
Establishment Using Resource Reservation Protocol Traffic
Engineering (RSVP-TE)", RFC5420, February 2009.
[RFC5521] Oki, E, T. Takeda, and A. Farrel, "Extensions to the Path
Computation Element Communication Protocol (PCEP) for
Route Exclusions", RFC 5521, April 2009.
[RFC6205] Tomohiro, O. and D. Li, "Generalized Labels for Lambda-
Switching Capable Label Switching Routers", RFC 6205,
January, 2011.
[RFC7570] Margaria, et al., "Label Switched Path (LSP) Attribute in
the Explicit Route Object (ERO)", RFC 7570, July 2015.
[RFC7689] Bernstein et al, "Signaling Extensions for Wavelength
Switched Optical Networks", RFC 7689, November 2015.
[RFC7688] Y. Lee, and G. Bernstein, "OSPF Enhancement for Signal and
Network Element Compatibility for Wavelength Switched
Optical Networks", RFC 7688, November 2015.
[RFC7698] O. Gonzalez de Dios, R. Casellas, editors, "Framework and
Requirements for GMPLS-Based Control of Flexi-Grid Dense
Wavelength Division Multiplexing (DWDM) Networks", RFC
7698, November 2015.
[RFC7581] Bernstein and Lee, "Routing and Wavelength Assignment
Information Encoding for Wavelength Switched Optical
Networks", RFC7581, June 2015.
Lee et al. Expires June 2019 [Page 18]
Internet-Draft PCEP Extension for Flexible Grid February 2019
[RFC7579] Bernstein and Lee, "General Network Element Constraint
Encoding for GMPLS Controlled Networks", RFC 7579, June
2015.
[PCEP-WSON] Y. Lee (Ed.), and R. Casellas (Ed.), "PCEP Extension for
WSON Routing and Wavelength Assignment", draft-ietf-pce-
wson-rwa-ext, work in progress.
10. Contributors
Lee et al. Expires June 2019 [Page 19]
Internet-Draft PCEP Extension for Flexible Grid February 2019
Authors' Addresses
Young Lee, Editor
Huawei Technologies
Email: leeyoung@huawei.com
Haomian Zheng
Huawei Technologies
Email: zhenghaomian@huawei.com
Ramon Casellas
CTTC
Av. Carl Friedrich Gauss n7
Castelldefels, Barcelona 08860
Spain
Email: ramon.casellas@cttc.es
Ricard Vilalta
CTTC
Email: ricard.vilalta@cttc.es
Daniele Ceccarelli
Ericsson AB
Gronlandsgatan 21
Kista - Stockholm
Email: daniele.ceccarelli@ericsson.com
Francesco Lazzeri
Ericsson
Via Melen 77
Genova - Italy
Email: francesco.lazzeri@ericsson.com
Lee et al. Expires June 2019 [Page 20]
