Internet DRAFT - draft-ietf-pce-gmpls-pcep-extensions
draft-ietf-pce-gmpls-pcep-extensions
Network Working Group C. Margaria, Ed.
Internet-Draft Juniper
Intended status: Standards Track O. Gonzalez de Dios, Ed.
Expires: June 14, 2020 Telefonica Investigacion y Desarrollo
F. Zhang, Ed.
Huawei Technologies
December 12, 2019
PCEP extensions for GMPLS
draft-ietf-pce-gmpls-pcep-extensions-16
Abstract
A Path Computation Element (PCE) provides path computation functions
for Multiprotocol Label Switching (MPLS) and Generalized MPLS (GMPLS)
networks. Additional requirements for GMPLS are identified in
RFC7025.
This memo provides extensions to the Path Computation Element
communication Protocol (PCEP) for the support of the GMPLS control
plane to address those requirements.
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
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material or to cite them other than as "work in progress."
This Internet-Draft will expire on June 14, 2020.
Copyright Notice
Copyright (c) 2019 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents
(https://trustee.ietf.org/license-info) in effect on the date of
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 3
1.2. PCEP Requirements for GMPLS . . . . . . . . . . . . . . . 5
1.3. Requirements Applicability . . . . . . . . . . . . . . . 5
1.3.1. Requirements on Path Computation Request . . . . . . 6
1.3.2. Requirements on Path Computation Response . . . . . . 7
1.4. Existing Support for GMPLS in Base PCEP Objects and its
Limitations . . . . . . . . . . . . . . . . . . . . . . . 7
2. PCEP Objects and Extensions . . . . . . . . . . . . . . . . . 10
2.1. GMPLS Capability Advertisement . . . . . . . . . . . . . 10
2.1.1. GMPLS Computation TLV in the Existing PCE Discovery
Protocol . . . . . . . . . . . . . . . . . . . . . . 10
2.1.2. OPEN Object Extension GMPLS-CAPABILITY TLV . . . . . 10
2.2. RP Object Extension . . . . . . . . . . . . . . . . . . . 11
2.3. BANDWIDTH Object Extensions . . . . . . . . . . . . . . . 12
2.4. LOAD-BALANCING Object Extensions . . . . . . . . . . . . 14
2.5. END-POINTS Object Extensions . . . . . . . . . . . . . . 16
2.5.1. Generalized Endpoint Object Type . . . . . . . . . . 17
2.5.2. END-POINTS TLV Extensions . . . . . . . . . . . . . . 20
2.6. IRO Extension . . . . . . . . . . . . . . . . . . . . . . 24
2.7. XRO Extension . . . . . . . . . . . . . . . . . . . . . . 24
2.8. LSPA Extensions . . . . . . . . . . . . . . . . . . . . . 26
2.9. NO-PATH Object Extension . . . . . . . . . . . . . . . . 26
2.9.1. Extensions to NO-PATH-VECTOR TLV . . . . . . . . . . 27
3. Additional Error-Types and Error-Values Defined . . . . . . . 27
4. Manageability Considerations . . . . . . . . . . . . . . . . 29
4.1. Control of Function through Configuration and Policy . . 29
4.2. Information and Data Models . . . . . . . . . . . . . . . 29
4.3. Liveness Detection and Monitoring . . . . . . . . . . . . 29
4.4. Verifying Correct Operation . . . . . . . . . . . . . . . 30
4.5. Requirements on Other Protocols and Functional Components 30
4.6. Impact on Network Operation . . . . . . . . . . . . . . . 30
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 30
5.1. PCEP Objects . . . . . . . . . . . . . . . . . . . . . . 30
5.2. Endpoint type field in Generalized END-POINTS Object . . 31
5.3. New PCEP TLVs . . . . . . . . . . . . . . . . . . . . . . 32
5.4. RP Object Flag Field . . . . . . . . . . . . . . . . . . 32
5.5. New PCEP Error Codes . . . . . . . . . . . . . . . . . . 32
5.6. New NO-PATH-VECTOR TLV Fields . . . . . . . . . . . . . . 33
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5.7. New Subobject for the Include Route Object . . . . . . . 34
5.8. New Subobject for the Exclude Route Object . . . . . . . 34
5.9. New GMPLS-CAPABILITY TLV Flag Field . . . . . . . . . . . 35
6. Security Considerations . . . . . . . . . . . . . . . . . . . 35
7. Contributing Authors . . . . . . . . . . . . . . . . . . . . 36
8. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 38
9. References . . . . . . . . . . . . . . . . . . . . . . . . . 38
9.1. Normative References . . . . . . . . . . . . . . . . . . 38
9.2. Informative References . . . . . . . . . . . . . . . . . 42
Appendix A. LOAD-BALANCING Usage for SDH Virtual Concatenation . 43
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 43
1. Introduction
Although [RFC4655] defines the PCE architecture and framework for
both MPLS and GMPLS networks, most preexisting PCEP RFCs [RFC5440],
[RFC5521], [RFC5541], [RFC5520] are focused on MPLS networks, and do
not cover the wide range of GMPLS networks. This document
complements these RFCs by addressing the extensions required for
GMPLS applications and routing requests, for example for Optical
Transport Network (OTN) and Wavelength Switched Optical Network
(WSON) networks.
The functional requirements to be addressed by the PCEP extensions to
support these applications are fully described in [RFC7025] and
[RFC7449].
1.1. Terminology
This document uses terminologies from the PCE architecture document
[RFC4655], the PCEP documents including [RFC5440], [RFC5521],
[RFC5541], [RFC5520], [RFC7025] and [RFC7449], and the GMPLS
documents such as [RFC3471], [RFC3473] and so on. Note that it is
expected the reader is familiar with these documents. The following
abbreviations are used in this document
ODU ODU Optical Channel Data Unit [G.709-v3]
OTN Optical Transport Network [G.709-v3]
L2SC Layer-2 Switch Capable [RFC3471]
TDM Time-Division Multiplex Capable [RFC3471]
LSC Lambda Switch Capable [RFC3471]
SONET Synchronous Optical Networking
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SDH Synchronous Digital Hierarchy
PCC Path Computation Client
RSVP-TE Resource Reservation Protocol - Traffic Engineering
LSP Label Switched Path
TE-LSP Traffic Engineering LSP
IRO Include Route Object
ERO Explicit Route Object
XRO eXclude Route Object
RRO Record Route Object
LSPA LSP Attribute
SRLG Shared Risk Link Group
NVC Number of Virtual Components [RFC4328][RFC4606]
NCC Number of Contiguous Components [RFC4328][RFC4606]
MT Multiplier [RFC4328][RFC4606]
RCC Requested Contiguous Concatenation [RFC4606]
PCReq Path Computation Request [RFC5440]
PCRep Path Computation Reply [RFC5440]
MEF Metro Ethernet Forum
SSON Spectrum-Switched Optical Network
P2MP Point to Multi-Point
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in BCP
14 [RFC2119] [RFC8174] when, and only when, they appear in all
capitals, as shown here.
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1.2. PCEP Requirements for GMPLS
The document [RFC7025] describes the set of PCEP requirements to
support GMPLS TE-LSPs. This document assumes a significant
familiarity with [RFC7025] and existing PCEP extensions. As a short
overview, those requirements can be broken down into the following
categories.
o Which data flow is switched by the LSP: a combination of Switching
type (for instance L2SC or TDM ), LSP Encoding type (e.g.,
Ethernet, SONET/SDH) and sometimes the Signal Type (e.g., in case
of TDM/LSC switching capability).
o Data flow specific traffic parameters, which are technology
specific. For instance, in SDH/SONET and [G.709-v3] OTN networks
the Concatenation Type and the Concatenation Number have an
influence on the switched data and on which link it can be
supported
o Support for asymmetric bandwidth requests.
o Support for unnumbered interface identifiers, as defined in
[RFC3477]
o Label information and technology specific label(s) such as
wavelength labels as defined in [RFC6205]. A PCC should also be
able to specify a label restriction similar to the one supported
by RSVP-TE in [RFC3473].
o Ability to indicate the requested granularity for the path ERO:
node, link or label. This is to allow the use of the explicit
label control feature of RSVP-TE.
The requirements of [RFC7025] apply to several objects conveyed by
PCEP, this is described in Section 1.3. Some of the requirements of
[RFC7025] are already supported in existing documents, as described
in Section 1.4.
This document describes a set of PCEP extensions, including new
object types, TLVs, encodings, error codes and procedures, in order
to fulfill the aforementioned requirements not covered in existing
RFCs.
1.3. Requirements Applicability
This section follows the organization of [RFC7025] Section 3 and
indicates, for each requirement, the affected piece of information
carried by PCEP and its scope.
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1.3.1. Requirements on Path Computation Request
(1) Switching capability/type: as described in [RFC3471] this piece
of information is used with the Encoding Type and Signal Type
to fully describe the switching technology and data carried by
the TE-LSP. This is applicable to the TE-LSP itself and also
to the TE-LSP endpoint (Carried in the END-POINTS object for
MPLS networks in [RFC5440]) when considering multiple network
layers. Inter-layer path computation requirements are
addressed in in [RFC8282] which addressing the TE-LSP itself,
but the TE-LSP endpoints are not addressed.
(2) Encoding type: see (1).
(3) Signal type: see (1).
(4) Concatenation type: this parameter and the Concatenation Number
(5) are specific to some TDM (SDH and ODU) switching
technology. They MUST be described together and are used to
derive the requested resource allocation for the TE-LSP. It is
scoped to the TE-LSP and is related to the [RFC5440] BANDWIDTH
object in MPLS networks. See [RFC4606] and [RFC4328] about
concatenation information.
(5) Concatenation number: see (4).
(6) Technology-specific label(s): as described in [RFC3471] the
GMPLS Labels are specific to each switching technology. They
can be specified on each link and also on the TE-LSP endpoints
, in WSON networks for instance, as described in [RFC6163].
The label restriction can apply to endpoints and on each hop,
the related PCEP objects are END-POINTS, IRO, XRO and RRO.
(7) End-to-End (E2E) path protection type: as defined in [RFC4872],
this is applicable to the TE-LSP. In MPLS networks the related
PCEP object is LSPA (carrying local protection information).
(8) Administrative group: as defined in [RFC3630], this information
is already carried in the LSPA object.
(9) Link protection type: as defined in [RFC4872], this is
applicable to the TE-LSP and is carried in association with the
E2E path protection type.
(10) Support for unnumbered interfaces: as defined in [RFC3477].
Its scope and related objects are the same as labels
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(11) Support for asymmetric bandwidth requests: as defined
[RFC6387], the scope is similar to (4)
(12) Support for explicit label control during the path computation.
This affects the TE-LSP and amount of information returned in
the ERO.
(13) Support of label restrictions in the requests/responses: This
is described in (6).
1.3.2. Requirements on Path Computation Response
(1) Path computation with concatenation: This is related to Path
Computation request requirement (4). In addition there is a
specific type of concatenation called virtual concatenation that
allows different routes to be used between the endpoints. It is
similar to the semantic and scope of the LOAD-BALANCING in MPLS
networks.
(2) Label constraint: The PCE should be able to include Labels in
the path returned to the PCC, the related object is the ERO
object.
(3) Roles of the routes: as defined in [RFC4872], this is applicable
to the TE-LSP and is carried in association with the E2E path
protection type.
1.4. Existing Support for GMPLS in Base PCEP Objects and its
Limitations
The support provided by specifications in [RFC8282] and [RFC5440] for
the requirements listed in [RFC7025] is summarized in Table 1 and
Table 2. In some cases the support may not be complete, as noted,
and additional support need to be provided in this specification.
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Req. Name Support
1 Switching capability/type SWITCH-LAYER
(RFC8282)
2 Encoding type SWITCH-LAYER
(RFC8282)
3 Signal type SWITCH-LAYER
(RFC8282)
4 Concatenation type No
5 Concatenation number No
6 Technology-specific label (Partial) ERO
(RFC5440)
7 End-to-End (E2E) path protection type No
8 Administrative group LSPA (RFC5440)
9 Link protection type No
10 Support for unnumbered interfaces (Partial) ERO
(RFC5440)
11 Support for asymmetric bandwidth requests No
12 Support for explicit label control during the No
path computation
13 Support of label restrictions in the No
requests/responses
Table 1: RFC7025 Section 3.1 requirements support
Req. Name Support
1 Path computation with concatenation No
2 Label constraint No
3 Roles of the routes No
Table 2: RFC7025 Section 3.2 requirements support
As described in Section 1.3 PCEP as of [RFC5440], [RFC5521] and
[RFC8282], supports the following objects, included in requests and
responses, related to the described requirements.
From [RFC5440]:
o END-POINTS: related to requirements (1, 2, 3, 6, 10 and 13). The
object only supports numbered endpoints. The context specifies
whether they are node identifiers or numbered interfaces.
o BANDWIDTH: related to requirements (4, 5 and 11). The data rate
is encoded in the bandwidth object (as IEEE 32 bit float).
[RFC5440] does not include the ability to convey an encoding
proper to all GMPLS-controlled networks.
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o ERO: related to requirements (6, 10, 12 and 13). The ERO content
is defined in RSVP in [RFC3209][RFC3473][RFC3477][RFC7570] and
supports all the requirements already.
o LSPA: related to requirements (7, 8 and 9). The requirement 8
(setup and holding priorities) is already supported.
From [RFC5521]:
o XRO:
* This object allows excluding (strict or not) resources and is
related to requirements (6, 10 and 13). It also includes the
requested diversity (node, link or SRLG).
* When the F bit is set, the request indicates that the existing
path has failed and the resources present in the RRO can be
reused.
From [RFC8282]:
o SWITCH-LAYER: addresses requirements (1, 2 and 3) for the TE-LSP
and indicates which layer(s) should be considered. The object can
be used to represent the RSVP-TE generalized label request. It
does not address the endpoints case of requirements (1, 2 and 3).
o REQ-ADAP-CAP: indicates the adaptation capabilities requested, can
also be used for the endpoints in case of mono-layer computation
The gaps in functional coverage of the base PCEP objects are:
The BANDWIDTH and LOAD-BALANCING objects do not describe the
details of the traffic request (requirements 4 and 5, for example
NVC, multiplier) in the context of GMPLS networks, for instance
TDM or OTN networks.
The END-POINTS object does not allow specifying an unnumbered
interface, nor potential label restrictions on the interface
(requirements 6, 10 and 13). Those parameters are of interest in
case of switching constraints.
The Include/eXclude Route Objects (IRO/XRO) do not allow the
inclusion/exclusion of labels (requirements 6, 10 and 13).
Base attributes do not allow expressing the requested link
protection level and/or the end-to-end protection attributes.
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The PCEP extensions defined later in this document to cover the gaps
are:
Two new object types are defined for the BANDWIDTH object
(Generalized bandwidth, Generalized bandwidth of existing TE-LSP
for which a reoptimization is requested).
A new object type is defined for the LOAD-BALANCING object
(Generalized Load Balancing).
A new object type is defined for the END-POINTS object
(Generalized Endpoint).
A new TLV is added to the Open message for capability negotiation.
A new TLV is added to the LSPA object.
The Label TLV is now allowed in the IRO and XRO objects.
In order to indicate the used routing granularity in the response,
a new flag in the RP object is added.
2. PCEP Objects and Extensions
This section describes the necessary PCEP objects and extensions.
The PCReq and PCRep messages are defined in [RFC5440]. This document
does not change the existing grammars.
2.1. GMPLS Capability Advertisement
2.1.1. GMPLS Computation TLV in the Existing PCE Discovery Protocol
IGP-based PCE Discovery (PCED) is defined in [RFC5088] and [RFC5089]
for the OSPF and IS-IS protocols. Those documents have defined bit 0
in PCE-CAP-FLAGS Sub-TLV of the PCED TLV as "Path computation with
GMPLS link constraints". This capability is optional and can be used
to detect GMPLS-capable PCEs. PCEs that set the bit to indicate
support of GMPLS path computation MUST follow the procedures in
Section 2.1.2 to further qualify the level of support during PCEP
session establishment.
2.1.2. OPEN Object Extension GMPLS-CAPABILITY TLV
In addition to the IGP advertisement, a PCEP speaker MUST be able to
discover the other peer GMPLS capabilities during the Open message
exchange. This capability is also useful to avoid misconfigurations.
This document defines a GMPLS-CAPABILITY TLV for use in the OPEN
object to negotiate the GMPLS capability. The inclusion of this TLV
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in the Open message indicates that the PCEP speaker support the PCEP
extensions defined in the document. A PCEP speaker that is able to
support the GMPLS extensions defined in this document MUST include
the GMPLS-CAPABILITY TLV on the Open message. If one of the PCEP
peers does not include the GMPLS-CAPABILITY TLV in the Open message,
the peers MUST NOT make use of the objects and TLVs defined in this
document.
If the PCEP speaker supports the extensions of this specification but
did not advertise the GMPLS-CAPABILITY capability, upon receipt of a
message from the PCE including an extension defined in this document,
it MUST generate a PCEP Error (PCErr) with Error-Type=10 (Reception
of an invalid object) and Error-value=TBA-42 (Missing GMPLS-
CAPABILITY TLV), and it SHOULD terminate the PCEP session.
IANA has allocated value TBA-1 from the "PCEP TLV Type Indicators"
sub-registry, as documented in Section 5.3 ("New PCEP TLVs"). The
description is "GMPLS-CAPABILITY". Its format is shown in the
following figure.
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=TBA-1 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Flags |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
No Flags are defined in this document, they are reserved for future
use.
2.2. RP Object Extension
Explicit label control (ELC) is a procedure supported by RSVP-TE,
where the outgoing labels are encoded in the ERO. As a consequence,
the PCE can provide such labels directly in the path ERO. Depending
on policies or switching layer, it can be necessary for the PCC to
use explicit label control or explicit link ids, thus it needs to
indicate in the PCReq which granularity it is expecting in the ERO.
This corresponds to requirement 12 of [RFC7025]. The possible
granularities can be node, link or label. The granularities are
inter-dependent, in the sense that link granularity implies the
presence of node information in the ERO; similarly, a label
granularity implies that the ERO contains node, link and label
information.
A new 2-bit routing granularity (RG) flag (Bits TBA-13) is defined in
the RP object. The values are defined as follows
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0: reserved
1: node
2: link
3: label
Table 3: RG flag
The flag in the RP object indicates the requested route granularity.
The PCE SHOULD follow this granularity and MAY return a NO-PATH if
the requested granularity cannot be provided. The PCE MAY return any
granularity on the route based on its policy. The PCC can decide if
the ERO is acceptable based on its content.
If a PCE honored the requested routing granularity for a request, it
MUST indicate the selected routing granularity in the RP object
included in the response. Otherwise, the PCE MUST use the reserved
RG to leave the check of the ERO to the PCC. The RG flag is
backward-compatible with [RFC5440]: the value sent by an
implementation (PCC or PCE) not supporting it will indicate a
reserved value.
2.3. BANDWIDTH Object Extensions
From [RFC5440] the object carrying the requested size for the TE-LSP
is the BANDWIDTH object. The object types 1 and 2 defined in
[RFC5440] do not describe enough information to describe the TE-LSP
bandwidth in GMPLS networks. The BANDWIDTH object encoding has to be
extended to allow the object to express the bandwidth as described in
[RFC7025]. RSVP-TE extensions for GMPLS provide a set of encodings
allowing such representation in an unambiguous way, this is encoded
in the RSVP-TE TSpec and FlowSpec objects. This document extends the
BANDWIDTH object with new object types reusing the RSVP-TE encoding.
The following possibilities are supported by the extended encoding:
o Asymmetric bandwidth (different bandwidth in forward and reverse
direction), as described in [RFC6387]
o GMPLS (SDH/SONET, G.709, ATM, MEF, etc.) parameters.
This corresponds to requirements 3, 4, 5 and 11 of [RFC7025]
Section 3.1.
This document defines two Object Types for the BANDWIDTH object:
TBA-2 Generalized bandwidth
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TBA-3 Generalized bandwidth of an existing TE-LSP for which a
reoptimization is requested
The definitions below apply for Object Type TBA-2 and TBA-3. The
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Bandwidth Spec Length | Rev. Bandwidth Spec Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Bw Spec Type | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
~ Generalized Bandwidth ~
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
~ Optional: Reverse Generalized Bandwidth ~
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
~ Optional TLVs ~
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
The BANDWIDTH object type TBA-2 and TBA-3 have a variable length.
The 16-bit Bandwidth Spec Length field indicates the length of the
Generalized Bandwidth field. The Bandwidth Spec Length MUST be
strictly greater than 0. The 16-bit Reverse Bandwidth Spec Length
field indicates the length of the Reverse Generalized Bandwidth
field. The Reverse Bandwidth Spec Length MAY be equal to 0.
The Bw Spec Type field determines which type of bandwidth is
represented by the object.
The Bw Spec Type corresponds to the RSVP-TE SENDER_TSPEC (Object
Class 12) C-Types
The encoding of the fields Generalized Bandwidth and Reverse
Generalized Bandwidth is the same as the Traffic Parameters carried
in RSVP-TE, it can be found in the following references. It is to be
noted that the RSVP-TE traffic specification MAY also include TLVs
(e.g., [RFC6003] different from the PCEP TLVs).
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Bw Spec Type Name Reference
2 Intserv [RFC2210]
4 SONET/SDH [RFC4606]
5 G.709 [RFC4328]
6 Ethernet [RFC6003]
7 OTN-TDM [RFC7139]
8 SSON [RFC7792]
Table 4: Generalized Bandwidth and Reverse Generalized Bandwidth
field encoding
When a PCC requests a bi-directional path with symmetric bandwidth,
it SHOULD only specify the Generalized Bandwidth field, and set the
Reverse Bandwidth Spec Length to 0. When a PCC needs to request a
bi-directional path with asymmetric bandwidth, it SHOULD specify the
different bandwidth in the forward and reverse directions with a
Generalized Bandwidth and Reverse Generalized Bandwidth fields.
The procedure described in [RFC5440] for the PCRep is unchanged: a
PCE MAY include the BANDWIDTH objects in the response to indicate the
BANDWIDTH of the path.
As specified in [RFC5440] in the case of the reoptimization of a TE-
LSP, the bandwidth of the existing TE-LSP MUST also be included in
addition to the requested bandwidth if and only if the two values
differ. The Object Type TBA-3 MAY be used instead of the previously
specified object type 2 to indicate the existing TE-LSP bandwidth
originally specified with object type TBA-2. A PCC that requested a
path with a BANDWIDTH object of object type 1 MUST use object type 2
to represent the existing TE-LSP BANDWIDTH.
OPTIONAL TLVs MAY be included within the object body to specify more
specific bandwidth requirements. No TLVs for the Object Type TBA-2
and TBA-3 are defined by this document.
2.4. LOAD-BALANCING Object Extensions
The LOAD-BALANCING object [RFC5440] is used to request a set of at
most Max-LSP TE-LSP having in total the bandwidth specified in
BANDWIDTH, with each TE-LSP having at least a specified minimum
bandwidth. The LOAD-BALANCING follows the bandwidth encoding of the
BANDWIDTH object, and thus the existing definition from [RFC5440]
does not describe enough details for the bandwidth specification
expected by GMPLS.
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Similarly to the BANDWIDTH object, a new object type is defined to
allow a PCC to represent the bandwidth types supported by GMPLS
networks.
This document defines the Generalized Load Balancing object type
TBA-4 for the LOAD-BALANCING object. The Generalized Load Balancing
object type has a variable length.
The format of the Generalized Load Balancing object type 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Bandwidth Spec Length | Reverse Bandwidth Spec Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Bw Spec Type | Max-LSP | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Min Bandwidth Spec |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Min Reverse Bandwidth Spec (optional) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
~ Optional TLVs ~
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Bandwidth Spec Length (16 bits): the total length of the Min
Bandwidth Spec field. The length MUST be strictly greater than 0.
Reverse Bandwidth Spec Length (16 bits): the total length of the Min
Reverse Bandwidth Spec field. It MAY be equal to 0.
Bw Spec Type (8 bits): the bandwidth specification type, it
corresponds to the RSVP-TE SENDER_TSPEC (Object Class 12) C-Types.
Max-LSP (8 bits): maximum number of TE-LSPs in the set.
Min Bandwidth Spec (variable): specifies the minimum bandwidth
specification of each element of the TE-LSP set.
Min Reverse Bandwidth Spec (variable): specifies the minimum reverse
bandwidth specification of each element of the TE-LSP set.
The encoding of the fields Min Bandwidth Spec and Min Reverse
Bandwidth Spec is the same as in RSVP-TE SENDER_TSPEC object, it can
be found in Table 4 from Section 2.3 from this document.
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When a PCC requests a bi-directional path with symmetric bandwidth
while specifying load balancing constraints it SHOULD specify the Min
Bandwidth Spec field, and set the Reverse Bandwidth Spec Length to 0.
When a PCC needs to request a bi-directional path with asymmetric
bandwidth while specifying load balancing constraints, it MUST
specify the different bandwidth in forward and reverse directions
through a Min Bandwidth Spec and Min Reverse Bandwidth Spec fields.
OPTIONAL TLVs MAY be included within the object body to specify more
specific bandwidth requirements. No TLVs for the Generalized Load
Balancing object type are defined by this document.
The semantic of the LOAD-BALANCING object is not changed. If a PCC
requests the computation of a set of TE-LSPs with at most N TE-LSPs
so that it can carry generalized bandwidth X , each TE-LSP must at
least transport bandwidth B, it inserts a BANDWIDTH object specifying
X as the required bandwidth and a LOAD-BALANCING object with the Max-
LSP and Min Bandwidth Spec fields set to N and B, respectively. When
the BANDWIDTH and Min Bandwidth Spec can be summarized as scalars,
the sum of all TE-LSPs bandwith in the set is greater than X. The
mapping of X over N path with (at least) bandwidth B is technology
and possibly node specific. Each standard definition of the
transport technology is defining those mappings and are not repeated
in this document. A simplified example for SDH is described in
Appendix A
In all other cases, including for technologies based on statistical
multiplexing (e.g., InterServ, Ethernet), the exact bandwidth
management (e.g., Ethernet's Excessive Rate) is left to the PCE's
policies, according to the operator's configuration. If required,
further documents may introduce a new mechanism to finely express
complex load balancing policies within PCEP.
The BANDWITH and LOAD-BALANCING Bw Spec Type can be different
depending on the endpoint nodes architecture. When the PCE is not
able to handle those two Bw Spec Type, it MUST return a NO-PATH with
the bit "LOAD-BALANCING could not be performed with the bandwidth
constraits " set in the NO-PATH-VECTOR TLV.
2.5. END-POINTS Object Extensions
The END-POINTS object is used in a PCEP request message to specify
the source and the destination of the path for which a path
computation is requested. From [RFC5440], the source IP address and
the destination IP address are used to identify those. A new Object
Type is defined to address the following possibilities:
o Different source and destination endpoint types.
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o Label restrictions on the endpoint.
o Specification of unnumbered endpoints type as seen in GMPLS
networks.
The Object encoding is described in the following sections.
In path computation within a GMPLS context the endpoints can:
o Be unnumbered as described in [RFC3477].
o Have labels associated to them, specifying a set of constraints on
the allocation of labels.
o Have different switching capabilities
The IPv4 and IPv6 endpoints are used to represent the source and
destination IP addresses. The scope of the IP address (Node or
numbered Link) is not explicitly stated. It is also possible to
request a Path between a numbered link and an unnumbered link, or a
P2MP path between different type of endpoints.
This document defines the Generalized Endpoint object type TBA-5 for
the END-POINTS object. This new type also supports the specification
of constraints on the endpoint label to be used. The PCE might know
the interface restrictions but this is not a requirement. This
corresponds to requirements 6 and 10 of [RFC7025].
2.5.1. Generalized Endpoint Object Type
The Generalized Endpoint object type format consists of a body and a
list of TLVs scoped to this object. The TLVs give the details of the
endpoints and are described in Section 2.5.2. For each Endpoint
Type, a different grammar is defined. The TLVs defined to describe
an endpoint are:
1. IPv4 address endpoint.
2. IPv6 address endpoint.
3. Unnumbered endpoint.
4. Label request.
5. Label set.
The Label set TLV is used to restrict or suggest the label allocation
in the PCE. This TLV expresses the set of restrictions which may
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apply to signaling. Label restriction support can be an explicit or
a suggested value (Label set describing one label, with the L bit
respectively cleared or set), mandatory range restrictions (Label set
with L bit cleared) and optional range restriction (Label set with L
bit set). Endpoints label restriction may not be part of the RRO or
IRO. They can be included when following [RFC4003] in signaling for
egress endpoint, but ingress endpoint properties can be local to the
PCC and not signaled. To support this case the label set allows
indication which label are used in case of reoptimization. The label
range restrictions are valid in GMPLS-controlled networks, either by
PCC policy or depending on the switching technology used, for
instance on given Ethernet or ODU equipment having limited hardware
capabilities restricting the label range. Label set restriction also
applies to WSON networks where the optical senders and receivers are
limited in their frequency tunability ranges, consequently
restricting the possible label ranges on the interface in GMPLS. The
END-POINTS Object with Generalized Endpoint object type is encoded as
follow:
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 | Endpoint Type |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
~ TLVs ~
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Reserved bits SHOULD be set to 0 when a message is sent and ignored
when the message is received.
The Endpoint Type is defined as follow:
Value Type Meaning
0 Point-to-Point
1 Point-to-Multipoint New leaves to add
2 Old leaves to remove
3 Old leaves whose path can be
modified/reoptimized
4 Old leaves whose path has to be
left unchanged
5-244 Reserved
245-255 Experimental range
Table 5: Generalized Endpoint endpoint types
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The Endpoint Type is used to cover both point-to-point and different
point-to-multipoint endpoints. A PCE may accept only Endpoint Type
0: Endpoint Types 1-4 apply if the PCE implementation supports P2MP
path calculation. A PCE not supporting a given Endpoint Type SHOULD
respond with a PCErr with Error-Type=4 (Not supported object), Error-
value=TBA-15 (Unsupported endpoint type in END-POINTS Generalized
Endpoint object type). As per [RFC5440], a PCE unable to process
Generalized Endpoints may respond with Error-Type=3 (Unknown Object),
Error-value=2 (Unrecognized object Type) or Error-Type=4 (Not
supported object), Error-value=2 (Not supported object Type). The
TLVs present in the request object body MUST follow the following
[RFC5511] grammar:
<generalized-endpoint-tlvs>::=
<p2p-endpoints> | <p2mp-endpoints>
<p2p-endpoints> ::=
<endpoint> [<endpoint-restriction-list>]
<endpoint> [<endpoint-restriction-list>]
<p2mp-endpoints> ::=
<endpoint> [<endpoint-restriction-list>]
<endpoint> [<endpoint-restriction-list>]
[<endpoint> [<endpoint-restriction-list>]]...
For endpoint type Point-to-Point, 2 endpoint TLVs MUST be present in
the message. The first endpoint is the source and the second is the
destination.
For endpoint type Point-to-Multipoint, several END-POINT objects MAY
be present in the message and the exact meaning depending on the
endpoint type defined for the object. The first endpoint TLV is the
root and other endpoints TLVs are the leaves. The root endpoint MUST
be the same for all END-POINTS objects for that P2MP tree request.
If the root endpoint is not the same for all END-POINTS, a PCErr with
Error-Type=17 (P2MP END-POINTS Error), Error-value=4 (The PCE cannot
satisfy the request due to inconsistent END-POINTS) MUST be returned.
The procedure defined in [RFC8306] Section 3.10 also apply to the
Generalized Endpoint with Point-to-Multipoint endpoint types.
An endpoint is defined as follows:
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<endpoint>::=<IPV4-ADDRESS>|<IPV6-ADDRESS>|<UNNUMBERED-ENDPOINT>
<endpoint-restriction-list> ::= <endpoint-restriction>
[<endpoint-restriction-list>]
<endpoint-restriction> ::=
[<LABEL-REQUEST>][<label-restriction-list>]
<label-restriction-list> ::= <label-restriction>
[<label-restriction-list>]
<label-restriction> ::= <LABEL-SET>
The different TLVs are described in the following sections. A PCE
MAY support any or all of IPV4-ADDRESS, IPV6-ADDRESS, and UNNUMBERED-
ENDPOINT TLVs. When receiving a PCReq, a PCE unable to resolve the
identifier in one of those TLVs MUST respond using a PCRep with NO-
PATH and set the bit "Unknown destination" or "Unknown source" in the
NO-PATH-VECTOR TLV. The response SHOULD include the END-POINTS
object with only the unsupported TLV(s).
A PCE MAY support either or both of the LABEL-REQUEST and LABEL-SET
TLVs. If a PCE finds a non-supported TLV in the END-POINTS the PCE
MUST respond with a PCErr message with Error-Type=4 (Not supported
object) and Error-value=TBA-15 (Unsupported TLV present in END-POINTS
Generalized Endpoint object type) and the message SHOULD include the
END-POINTS object in the response with only the endpoint and endpoint
restriction TLV it did not understand. A PCE supporting those TLVs
but not being able to fulfil the label restriction MUST send a
response with a NO-PATH object which has the bit "No endpoint label
resource" or "No endpoint label resource in range" set in the NO-
PATH-VECTOR TLV. The response SHOULD include an END-POINTS object
containing only the TLV(s) related to the constraints the PCE could
not meet.
2.5.2. END-POINTS TLV Extensions
All endpoint TLVs have the standard PCEP TLV header as defined in
[RFC5440] Section 7.1. For the Generalized Endpoint Object Type the
TLVs MUST follow the ordering defined in Section 2.5.1.
2.5.2.1. IPV4-ADDRESS TLV
This TLV represents a numbered endpoint using IPv4 numbering, the
format of the IPv4-ADDRESS TLV value (TLV-Type=TBA-6) is as follows:
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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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IPv4 address |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
This TLV MAY be ignored, in which case a PCRep with NO-PATH SHOULD be
returned, as described in Section 2.5.1.
2.5.2.2. IPV6-ADDRESS TLV
This TLV represents a numbered endpoint using IPV6 numbering, the
format of the IPv6-ADDRESS TLV value (TLV-Type=TBA-7) 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IPv6 address (16 bytes) |
| |
| |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
This TLV MAY be ignored, in which case a PCRep with NO-PATH SHOULD be
returned, as described in Section 2.5.1.
2.5.2.3. UNNUMBERED-ENDPOINT TLV
This TLV represents an unnumbered interface. This TLV has the same
semantic as in [RFC3477]. The TLV value is encoded as follows (TLV-
Type=TBA-8)
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| LSR's Router ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Interface ID (32 bits) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
This TLV MAY be ignored, in which case a PCRep with NO-PATH SHOULD be
returned, as described in Section 2.5.1.
2.5.2.4. LABEL-REQUEST TLV
The LABEL-REQUEST TLV indicates the switching capability and encoding
type of the following label restriction list for the endpoint. The
value format and encoding is the same as described in [RFC3471]
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Section 3.1 Generalized label request. The LABEL-REQUEST TLV uses
TLV-Type=TBA-9. The Encoding Type indicates the encoding type, e.g.,
SONET/SDH/GigE etc., of the LSP with which the data is associated.
The Switching type indicates the type of switching that is being
requested on the endpoint. G-PID identifies the payload. This TLV
and the following one are defined to satisfy requirement 13 of
[RFC7025] for the endpoint. It is not directly related to the TE-LSP
label request, which is expressed by the SWITCH-LAYER object.
On the path calculation request only the GENERALIZED-BANDWIDTH and
SWITCH-LAYER need to be coherent, the endpoint labels could be
different (supporting a different LABEL-REQUEST). Hence the label
restrictions include a Generalized label request in order to
interpret the labels. This TLV MAY be ignored, in which case a PCRep
with NO-PATH SHOULD be returned, as described in Section 2.5.1.
2.5.2.5. LABEL-SET TLV
Label or label range restrictions can be specified for the TE-LSP
endpoints. Those are encoded using the LABEL-SET TLV. The label
value need to be interpreted with a description on the Encoding and
switching type. The REQ-ADAP-CAP object from [RFC8282] can be used
in case of mono-layer request, however in case of multilayer it is
possible to have more than one object, so it is better to have a
dedicated TLV for the label and label request. These TLVs MAY be
ignored, in which case a response with NO-PATH SHOULD be returned, as
described in Section 2.5.1. TLVs are encoded as follows (following
[RFC5440]):
o LABEL-SET TLV, Type=TBA-10. The TLV Length is variable, Encoding
follows [RFC3471] Section 3.5 "Label set" with the addition of a U
bit, O bit and L bit. The L bit is used to represent a suggested
set of labels, following the semantic of SUGGESTED_LABEL defined
by [RFC3471].
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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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Action | Reserved |L|O|U| Label Type |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Subchannel 1 |
| ... |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
: : :
: : :
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Subchannel N |
| ... |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
A LABEL-SET TLV represents a set of possible labels that can be used
on an interface. If the L bit is cleared, the label allocated on the
first endpoint MUST be within the label set range. The action
parameter in the Label set indicates the type of list provided.
These parameters are described by [RFC3471] Section 3.5.1.
The U, O and L bits have the following meaning:
U: Upstream direction: The U bit is set for upstream (revers)
direction in case of bidirectional LSP.
O: Old Label: set when the TLV represent the old (previously
allocated) label in case of re-optimization. The R bit of the RP
object MUST be set to 1. If the L bit is set, this bit SHOULD be
set to 0 and ignored on receipt. When this bit is set, the Action
field MUST be set to 0 (Inclusive List) and the Label Set MUST
contain one subchannel.
L: Loose Label: set when the TLV indicates to the PCE a set of
preferred (ordered) labels to be used. The PCE MAY use those
labels for label allocation.
Labels TLV bits
Several LABEL_SET TLVs MAY be present with the O bit cleared,
LABEL_SET TLVs with L bit set can be combined with a LABEL_SET TLV
with L bit cleared. There MUST NOT be more than two LABEL_SET TLVs
present with the O bit set. If there are two LABEL_SET TLVs present,
there MUST NOT be more than one with the U bit set, and there MUST
NOT be more than one with the U bit cleared. For a given U bit
value, if more than one LABEL_SET TLV with the O bit set is present,
the first TLV MUST be processed and the following TLVs with the same
U and O bit MUST be ignored.
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A LABEL-SET TLV with the O and L bit set MUST trigger a PCErr message
with Error-Type=10 (Reception of an invalid object) Error-
value=TBA-25 (Wrong LABEL-SET TLV present with O and L bit set).
A LABEL-SET TLV with the O bit set and an Action Field not set to 0
(Inclusive list) or containing more than one subchannel MUST trigger
a PCErr message with Error-Type=10 (Reception of an invalid object)
Error-value=TBA-26 (Wrong LABEL-SET TLV present with O bit and wrong
format).
If a LABEL-SET TLV is present with O bit set, the R bit of the RP
object MUST be set, otherwise a PCErr message MUST be sent with
Error-Type=10 (Reception of an invalid object) Error-value=TBA-24
(LABEL-SET TLV present with O bit set but without R bit set in RP).
2.6. IRO Extension
The IRO as defined in [RFC5440] is used to include specific objects
in the path. RSVP-TE allows the inclusion of a label definition. In
order to fulfill requirement 13 of [RFC7025] the IRO needs to support
the new subobject type as defined in [RFC3473]:
Type Sub-object
TBA-38 LABEL
The Label subobject MUST follow a subobject identifying a link,
currently an IP address subobject (Type 1 or 2) or an interface ID
(type 4) subobject. If an IP address subobject is used, then the
given IP address MUST be associated with a link. More than one label
subobject MAY follow each link subobject. The procedure associated
with this subobject is as follows.
If the PCE is able to allocate labels (e.g., via explicit label
control) the PCE MUST allocate one label from within the set of label
values for the given link. If the PCE does not assign labels, then
it sends a response with a NO-PATH object, containing a NO-PATH-
VECTOR TLV with the bit 'No label resource in range' set.
2.7. XRO Extension
The XRO as defined in [RFC5521] is used to exclude specific objects
in the path. RSVP-TE allows the exclusion of certain labels
([RFC6001]). In order to fulfill requirement 13 of [RFC7025]
Section 3.1, the PCEP's XRO needs to support a new subobject to
enable label exclusion.
The encoding of the XRO Label subobject follows the encoding of the
Label ERO subobject defined in [RFC3473] and XRO subobject defined in
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[RFC5521]. The XRO Label subobject represent one Label and is
defined as follows:
XRO Subobject Type TBA-39: Label Subobject.
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|X| Type=TBA-39 | Length |U| Reserved | C-Type |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Label |
| ... |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
X (1 bit): as per [RFC5521]. The X-bit indicates whether the
exclusion is mandatory or desired. 0 indicates that the resource
specified MUST be excluded from the path computed by the PCE. 1
indicates that the resource specified SHOULD be excluded from the
path computed by the PCE, but MAY be included subject to PCE
policy and the absence of a viable path that meets the other
constraints and excludes the resource.
Type (7 bits): The Type of the XRO Label subobject is TBA-39.
Length (8 bits): see [RFC5521], the total length of the subobject
in bytes (including the Type and Length fields). The Length is
always divisible by 4.
U (1 bit): see [RFC3471] Section 6.1.
C-Type (8 bits): the C-Type of the included Label Object as
defined in [RFC3473].
Label: see [RFC3471].
The Label subobject MUST follow a subobject identifying a link,
currently an IP address subobject (Type 1 or 2) or an interface ID
(type 4) subobject. If an IP address subobject is used, then the
given IP address MUST be associated with a link. More than one label
subobject MAY follow each link subobject.
Type Sub-object
3 LABEL
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2.8. LSPA Extensions
The LSPA carries the LSP attributes. In the end-to-end recovery
context, this also includes the protection state information. A new
TLV is defined to fulfil requirement 7 of [RFC7025] Section 3.1 and
requirement 3 of [RFC7025] Section 3.2. This TLV contains the
information of the PROTECTION object defined by [RFC4872] and can be
used as a policy input. The LSPA object MAY carry a PROTECTION-
ATTRIBUTE TLV defined as: Type TBA-12: PROTECTION-ATTRIBUTE
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 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|S|P|N|O| Reserved | LSP Flags | Reserved | Link Flags|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|I|R| Reserved | Seg.Flags | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
The content is as defined in [RFC4872] Section 14, [RFC4873]
Section 6.1.
LSP (protection) Flags or Link flags field can be used by a PCE
implementation for routing policy input. The other attributes are
only meaningful for a stateful PCE.
This TLV is OPTIONAL and MAY be ignored by the PCE. If ignored by
the PCE, it MUST NOT include the TLV in the LSPA of the response.
When the TLV is used by the PCE, a LSPA object and the PROTECTION-
ATTRIBUTE TLV MUST be included in the response. Fields that were not
considered MUST be set to 0.
2.9. NO-PATH Object Extension
The NO-PATH object is used in PCRep messages in response to an
unsuccessful path computation request (the PCE could not find a path
satisfying the set of constraints). In this scenario, PCE MUST
include a NO-PATH object in the PCRep message. The NO-PATH object
MAY carry the NO-PATH-VECTOR TLV that specifies more information on
the reasons that led to a negative reply. In case of GMPLS networks
there could be some additional constraints that led to the failure
such as protection mismatch, lack of resources, and so on. Several
new flags have been defined in the 32-bit flag field of the NO-PATH-
VECTOR TLV but no modifications have been made in the NO-PATH object.
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2.9.1. Extensions to NO-PATH-VECTOR TLV
The modified NO-PATH-VECTOR TLV carrying the additional information
is as follows:
Bit number TBA-32 - Protection Mismatch (1-bit). Specifies the
mismatch of the protection type in the PROTECTION-ATTRIBUTE TLV in
the request.
Bit number TBA-33 - No Resource (1-bit). Specifies that the
resources are not currently sufficient to provide the path.
Bit number TBA-34 - Granularity not supported (1-bit). Specifies
that the PCE is not able to provide a path with the requested
granularity.
Bit number TBA-35 - No endpoint label resource (1-bit). Specifies
that the PCE is not able to provide a path because of the endpoint
label restriction.
Bit number TBA-36 - No endpoint label resource in range (1-bit).
Specifies that the PCE is not able to provide a path because of
the endpoint label set restriction.
Bit number TBA-37 - No label resource in range (1-bit). Specifies
that the PCE is not able to provide a path because of the label
set restriction.
3. Additional Error-Types and Error-Values Defined
A PCEP-ERROR object is used to report a PCEP error and is
characterized by an Error-Type that specifies the type of error while
Error-value that provides additional information about the error. An
additional error type and several error values are defined to
represent some of the errors related to the newly identified objects
related to GMPLS networks. For each PCEP error, an Error-Type and an
Error-value are defined. Error-Type 1 to 10 are already defined in
[RFC5440]. Additional Error-values are defined for Error-Types 4 and
10. A new Error-Type is defined (value TBA-27).
The Error-Type TBA-27 (path computation failure) is used to reflect
constraints not understood by the PCE, for instance when the PCE is
not able to understand the generalized bandwidth. If the constraints
are understood, but the PCE is unable to find with those constraints,
the NO-PATH is to be used.
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Error-Type Error-value
4 Not supported
object
value=TBA-14: Bandwidth Object type TBA-2 or TBA-3 not
supported
value=TBA-15: Unsupported endpoint type in
END-POINTS Generalized Endpoint
object type
value=TBA-16: Unsupported TLV present in END-POINTS
Generalized Endpoint object type
value=TBA-17: Unsupported granularity in the RP object
flags
10 Reception of
an invalid
object
value=TBA-18: Bad Bandwidth Object type TBA-2(Generalized
bandwidth) or TBA-3( Generalized bandwidth
of existing TE-LSP for which a
reoptimization is requested)
value=TBA-20: Unsupported LSP Protection Flags in
PROTECTION-ATTRIBUTE TLV
value=TBA-21: Unsupported Secondary LSP Protection Flags
in PROTECTION-ATTRIBUTE TLV
value=TBA-22: Unsupported Link Protection Type in
PROTECTION-ATTRIBUTE TLV
value=TBA-24: LABEL-SET TLV present with 0 bit set but
without R bit set in RP
value=TBA-25: Wrong LABEL-SET
TLV present with
0 and L bit set
value=TBA-26: Wrong LABEL-SET with O bit set and wrong
format
value=TBA-42: Missing GMPLS-CAPABILITY TLV
TBA-27 Path
computation
failure
value=0: Unassigned
value=TBA-28: Unacceptable request message
value=TBA-29: Generalized bandwidth value not supported
value=TBA-30: Label Set constraint could not be
met
value=TBA-31: Label constraint could not be
met
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4. Manageability Considerations
This section follows the guidance of [RFC6123].
4.1. Control of Function through Configuration and Policy
This document makes no change to the basic operation of PCEP and so
the requirements described in [RFC5440] Section 8.1. also apply to
this document. In addition to those requirements a PCEP
implementation may allow the configuration of the following
parameters:
Accepted RG in the RP object.
Default RG to use (overriding the one present in the PCReq)
Accepted BANDWIDTH object type TBA-2 and TBA-3 parameters in
request, default mapping to use when not specified in the request
Accepted LOAD-BALANCING object type TBA-4 parameters in request.
Accepted endpoint type and allowed TLVs in object END-POINTS with
object type Generalized Endpoint.
Accepted range for label restrictions in label restriction in END-
POINTS, or IRO or XRO objects
PROTECTION-ATTRIBUTE TLV acceptance and suppression.
The configuration of the above parameters is applicable to the
different sessions as described in [RFC5440] Section 8.1 (by default,
per PCEP peer, etc.).
4.2. Information and Data Models
This document makes no change to the basic operation of PCEP and so
the requirements described in [RFC5440] Section 8.2. also apply to
this document. This document does not introduce any new ERO sub
objects, so that the, ERO information model is already covered in
[RFC4802].
4.3. Liveness Detection and Monitoring
This document makes no change to the basic operation of PCEP and so
there are no changes to the requirements for liveness detection and
monitoring set out in [RFC4657] and [RFC5440] Section 8.3.
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4.4. Verifying Correct Operation
This document makes no change to the basic operations of PCEP and
considerations described in [RFC5440] Section 8.4. New errors
defined by this document should satisfy the requirement to log error
events.
4.5. Requirements on Other Protocols and Functional Components
No new Requirements on Other Protocols and Functional Components are
made by this document. This document does not require ERO object
extensions. Any new ERO subobject defined in the TEAS or CCAMP
working group can be adopted without modifying the operations defined
in this document.
4.6. Impact on Network Operation
This document makes no change to the basic operations of PCEP and
considerations described in [RFC5440] Section 8.6. In addition to
the limit on the rate of messages sent by a PCEP speaker, a limit MAY
be placed on the size of the PCEP messages.
5. IANA Considerations
IANA assigns values to the PCEP objects and TLVs. IANA is requested
to make some allocations for the newly defined objects and TLVs
defined in this document. Also, IANA is requested to manage the
space of flags that are newly added in the TLVs.
5.1. PCEP Objects
As described in Section 2.3, Section 2.4 and Section 2.5.1 new
Objects types are defined. IANA is requested to make the following
Object-Type allocations from the "PCEP Objects" sub-registry.
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Object 5
Class
Name BANDWIDTH
Object-Type TBA-2: Generalized bandwidth
TBA-3: Generalized bandwidth of an existing TE-LSP for
which a reoptimization is requested
Reference This document (Section 2.3)
Object 14
Class
Name LOAD-BALANCING
Object-Type TBA-4: Generalized Load Balancing
Reference This document (Section 2.4)
Object 4
Class
Name END-POINTS
Object-Type TBA-5: Generalized Endpoint
Reference This document (Section 2.5)
5.2. Endpoint type field in Generalized END-POINTS Object
IANA is requested to create a registry to manage the Endpoint Type
field of the END-POINTS object, Object Type Generalized Endpoint and
manage the code space.
New endpoint type in the Reserved range are assigned by Standards
Action [RFC8126]. Each endpoint type should be tracked with the
following attributes:
o Endpoint type
o Description
o Defining RFC
New endpoint type in the Experimental range are for experimental use;
these will not be registered with IANA and MUST NOT be mentioned by
RFCs.
The following values have been defined by this document.
(Section 2.5.1, Table 5):
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Value Type Meaning
0 Point-to-Point
1 Point-to-Multipoint New leaves to add
2 Old leaves to remove
3 Old leaves whose path can be
modified/reoptimized
4 Old leaves whose path has to be
left unchanged
5-244 Unassigned
245-255 Experimental range
5.3. New PCEP TLVs
IANA manages the PCEP TLV code point registry (see [RFC5440]). This
is maintained as the "PCEP TLV Type Indicators" sub-registry of the
"Path Computation Element Protocol (PCEP) Numbers" registry. IANA is
requested to do the following allocation. Note: TBA-11 is not used
Value Meaning Reference
TBA-6 IPV4-ADDRESS This document (Section 2.5.2.1)
TBA-7 IPV6-ADDRESS This document (Section 2.5.2.2)
TBA-8 UNNUMBERED-ENDPOINT This document (Section 2.5.2.3)
TBA-9 LABEL-REQUEST This document (Section 2.5.2.4)
TBA-10 LABEL-SET This document (Section 2.5.2.5)
TBA-12 PROTECTION-ATTRIBUTE This document (Section 2.8)
TBA-1 GMPLS-CAPABILITY This document (Section 2.1.2)
5.4. RP Object Flag Field
As described in Section 2.2 new flag are defined in the RP Object
Flag IANA is requested to make the following Object-Type allocations
from the "RP Object Flag Field" sub-registry.
Bit Description Reference
TBA-13 routing granularity (2 bits) This document, Section 2.2
(RG)
5.5. New PCEP Error Codes
As described in Section 3, new PCEP Error-Types and Error-values are
defined. IANA is requested to make the following allocation in the
"PCEP-ERROR Object Error Types and Values" registry.
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Error name Reference
Type=4 Not supported object [RFC5440]
Value=TBA-14: Bandwidth Object type TBA-2 or TBA-3 not This Document
supported
Value=TBA-15: Unsupported endpoint type in END-POINTS This Document
Generalized Endpoint object type
Value=TBA-16: Unsupported TLV present in END-POINTS This Document
Generalized Endpoint object type
Value=TBA-17: Unsupported granularity in the RP object This Document
flags
Type=10 Reception of an invalid object [RFC5440]
Value=TBA-18: Bad Bandwidth Object type This Document
TBA-2(Generalized bandwidth) or
TBA-3(Generalized bandwidth of existing
TE-LSP for which a reoptimization is
requested)
Value=TBA-20: Unsupported LSP Protection Flags in This Document
PROTECTION-ATTRIBUTE TLV
Value=TBA-21: Unsupported Secondary LSP Protection This Document
Flags in PROTECTION-ATTRIBUTE TLV
Value=TBA-22: Unsupported Link Protection Type in This Document
PROTECTION-ATTRIBUTE TLV
Value=TBA-24: LABEL-SET TLV present with 0 bit set but This Document
without R bit set in RP
Value=TBA-25: Wrong LABEL-SET TLV present with 0 and L This Document
bit set
Value=TBA-26: Wrong LABEL-SET with O bit set and wrong This Document
format
Value=TBA-42: Missing GMPLS-CAPABILITY TLV This Document
Type=TBA-27 Path computation failure This Document
Value=0 Unassigned This Document
Value=TBA-28: Unacceptable request message This Document
Value=TBA-29: Generalized bandwidth value not supported This Document
Value=TBA-30: Label Set constraint could not be met This Document
Value=TBA-31: Label constraint could not be met This Document
5.6. New NO-PATH-VECTOR TLV Fields
As described in Section 2.9.1, new NO-PATH-VECTOR TLV Flag Fields
have been defined. IANA is requested to do the following allocations
in the "NO-PATH-VECTOR TLV Flag Field" sub-registry.
Bit number TBA-32 - Protection Mismatch (1-bit). Specifies the
mismatch of the protection type of the PROTECTION-ATTRIBUTE TLV in
the request.
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Bit number TBA-33 - No Resource (1-bit). Specifies that the
resources are not currently sufficient to provide the path.
Bit number TBA-34 - Granularity not supported (1-bit). Specifies
that the PCE is not able to provide a path with the requested
granularity.
Bit number TBA-35 - No endpoint label resource (1-bit). Specifies
that the PCE is not able to provide a path because of the endpoint
label restriction.
Bit number TBA-36 - No endpoint label resource in range (1-bit).
Specifies that the PCE is not able to provide a path because of
the endpoint label set restriction.
Bit number TBA-37 - No label resource in range (1-bit). Specifies
that the PCE is not able to provide a path because of the label
set restriction.
Bit number TBA-40 - LOAD-BALANCING could not be performed with the
bandwidth constraits (1 bit). Specifies that the PCE is not able
to provide a path because it could not map the BANDWIDTH into the
parameters specified by the LOAD-BALANCING.
5.7. New Subobject for the Include Route Object
The "PCEP Parameters" registry contains a subregistry "IRO
Subobjects" with an entry for the Include Route Object (IRO).
IANA is requested to add a further subobject that can be carried in
the IRO as follows:
Subobject type Reference
TBA-38 Label subobject This Document
5.8. New Subobject for the Exclude Route Object
The "PCEP Parameters" registry contains a subregistry "XRO
Subobjects" with an entry for the XRO object (Exclude Route Object).
IANA is requested to add a further subobject that can be carried in
the XRO as follows:
Subobject type Reference
TBA-39 Label subobject This Document
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5.9. New GMPLS-CAPABILITY TLV Flag Field
IANA is requested to create a sub-registry to manage the Flag field
of the GMPLS-CAPABILITY TLV within the "Path Computation Element
Protocol (PCEP) Numbers" registry.
New bit numbers are to be assigned by Standards Action [RFC8126].
Each bit should be tracked with the following qualities:
o Bit number (counting from bit 0 as the most significant bit)
o Capability description
o Defining RFC
The initial contents of the sub-registry are empty, with all bits
marked unassigned
6. Security Considerations
GMPLS controls multiple technologies and types of network elements.
The LSPs that are established using GMPLS, whose paths can be
computed using the PCEP extensions to support GMPLS described in this
document, can carry a high volume of traffic and can be a critical
part of a network infrastructure. The PCE can then play a key role
in the use of the resources and in determining the physical paths of
the LSPs and thus it is important to ensure the identity of PCE and
PCC, as well as the communication channel. In many deployments there
will be a completely isolated network where an external attack is of
very low probability. However, there are other deployment cases in
which the PCC-PCE communication can be more exposed and there could
be more security considerations. Three main situations in case of an
attack in the GMPLS PCE context could happen:
o PCE Identity theft: A legitimate PCC could request a path for a
GMPLS LSP to a malicious PCE, which poses as a legitimate PCE.
The answer can make that the LSP traverses some geographical place
known to the attacker where confidentiality (sniffing), integrity
(traffic modification) or availability (traffic drop) attacks
could be performed by use of an attacker-controlled middlebox
device. Also, the resulting LSP can omit constraints given in the
requests (e.g., excluding certain fibers, avoiding some SRLGs)
which could make that the LSP which will be later set-up can look
perfectly fine, but will be in a risky situation. Also, the
result can lead to the creation of an LSP that does not provide
the desired quality and gives less resources than necessary.
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o PCC Identity theft: A malicious PCC, acting as a legitimate PCC,
requesting LSP paths to a legitimate PCE can obtain a good
knowledge of the physical topology of a critical infrastructure.
It could get to know enough details to plan a later physical
attack.
o Message inspection: As in the previous case, knowledge of an
infrastructure can be obtained by sniffing PCEP messages.
The security mechanisms can provide authentication and
confidentiality for those scenarios where the PCC-PCE communication
cannot be completely trusted. [RFC8253] provides origin
verification, message integrity and replay protection, and ensures
that a third party cannot decipher the contents of a message.
In order to protect against the malicious PCE case the PCC SHOULD
have policies in place to accept or not the path provided by the PCE.
Those policies can verify if the path follows the provided
constraints. In addition, technology specific data plane mechanism
can be used (following [RFC5920] Section 5.8) to verify the data
plane connectivity and deviation from constraints.
The document [RFC8253] describes the usage of Transport Layer
Security (TLS) to enhance PCEP security. The document describes the
initiation of the TLS procedures, the TLS handshake mechanisms, the
TLS methods for peer authentication, the applicable TLS ciphersuites
for data exchange, and the handling of errors in the security checks.
PCE and PCC SHOULD use [RFC8253] mechanism to protect against
malicious PCC and PCE.
Finally, as mentioned by [RFC7025] the PCEP extensions to support
GMPLS should be considered under the same security as current PCE
work and this extension will not change the underlying security
issues. However, given the critical nature of the network
infrastructures under control by GMPLS, the security issues described
above should be seriously considered when deploying a GMPLS-PCE based
control plane for such networks. For more information on the
security considerations on a GMPLS control plane, not only related to
PCE/PCEP, [RFC5920] provides an overview of security vulnerabilities
of a GMPLS control plane.
7. Contributing Authors
Elie Sfeir
Coriant
St Martin Strasse 76
Munich, 81541
Germany
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Email: elie.sfeir@coriant.com
Franz Rambach
Nockherstrasse 2-4,
Munich 81541
Germany
Phone: +49 178 8855738
Email: franz.rambach@cgi.com
Francisco Javier Jimenez Chico
Telefonica Investigacion y Desarrollo
C/ Emilio Vargas 6
Madrid, 28043
Spain
Phone: +34 91 3379037
Email: fjjc@tid.es
Huawei Technologies
Suresh BR
Shenzhen
China
Email: sureshbr@huawei.com
Young Lee
1700 Alma Drive, Suite 100
Plano, TX 75075
USA
Phone: (972) 509-5599 (x2240)
Email: ylee@huawei.com
SenthilKumar S
Shenzhen
China
Email: senthilkumars@huawei.com
Jun Sun
Shenzhen
China
Email: johnsun@huawei.com
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CTTC - Centre Tecnologic de Telecomunicacions de Catalunya
Ramon Casellas
PMT Ed B4 Av. Carl Friedrich Gauss 7
08860 Castelldefels (Barcelona)
Spain
Phone: (34) 936452916
Email: ramon.casellas@cttc.es
8. Acknowledgments
The research of Ramon Casellas, Francisco Javier Jimenez Chico, Oscar
Gonzalez de Dios, Cyril Margaria, and Franz Rambach leading to these
results has received funding from the European Community's Seventh
Framework Program FP7/2007-2013 under grant agreement no 247674 and
no 317999.
The authors would like to thank Julien Meuric, Lyndon Ong, Giada
Lander, Jonathan Hardwick, Diego Lopez, David Sinicrope, Vincent
Roca, Dhruv Dhody, Adrian Farrel and Tianran Zhou for their review
and useful comments to the document.
Thanks to Alisa Cooper, Benjamin Kaduk, Elwun-davies, Martin
Vigoureux, Roman Danyliw, and Suresh Krishnan for the IESG comments
9. References
9.1. Normative References
[G.709-v3]
ITU-T, "Interfaces for the optical transport network,
Recommendation G.709/Y.1331", June 2016,
<https://www.itu.int/rec/T-REC-G.709-201606-I/en>.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/info/rfc2119>.
[RFC2210] Wroclawski, J., "The Use of RSVP with IETF Integrated
Services", RFC 2210, DOI 10.17487/RFC2210, September 1997,
<https://www.rfc-editor.org/info/rfc2210>.
[RFC3209] Awduche, D., Berger, L., Gan, D., Li, T., Srinivasan, V.,
and G. Swallow, "RSVP-TE: Extensions to RSVP for LSP
Tunnels", RFC 3209, DOI 10.17487/RFC3209, December 2001,
<https://www.rfc-editor.org/info/rfc3209>.
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[RFC3471] Berger, L., Ed., "Generalized Multi-Protocol Label
Switching (GMPLS) Signaling Functional Description",
RFC 3471, DOI 10.17487/RFC3471, January 2003,
<https://www.rfc-editor.org/info/rfc3471>.
[RFC3473] Berger, L., Ed., "Generalized Multi-Protocol Label
Switching (GMPLS) Signaling Resource ReserVation Protocol-
Traffic Engineering (RSVP-TE) Extensions", RFC 3473,
DOI 10.17487/RFC3473, January 2003,
<https://www.rfc-editor.org/info/rfc3473>.
[RFC3477] Kompella, K. and Y. Rekhter, "Signalling Unnumbered Links
in Resource ReSerVation Protocol - Traffic Engineering
(RSVP-TE)", RFC 3477, DOI 10.17487/RFC3477, January 2003,
<https://www.rfc-editor.org/info/rfc3477>.
[RFC3630] Katz, D., Kompella, K., and D. Yeung, "Traffic Engineering
(TE) Extensions to OSPF Version 2", RFC 3630,
DOI 10.17487/RFC3630, September 2003,
<https://www.rfc-editor.org/info/rfc3630>.
[RFC4003] Berger, L., "GMPLS Signaling Procedure for Egress
Control", RFC 4003, DOI 10.17487/RFC4003, February 2005,
<https://www.rfc-editor.org/info/rfc4003>.
[RFC4328] Papadimitriou, D., Ed., "Generalized Multi-Protocol Label
Switching (GMPLS) Signaling Extensions for G.709 Optical
Transport Networks Control", RFC 4328,
DOI 10.17487/RFC4328, January 2006,
<https://www.rfc-editor.org/info/rfc4328>.
[RFC4606] Mannie, E. and D. Papadimitriou, "Generalized Multi-
Protocol Label Switching (GMPLS) Extensions for
Synchronous Optical Network (SONET) and Synchronous
Digital Hierarchy (SDH) Control", RFC 4606,
DOI 10.17487/RFC4606, August 2006,
<https://www.rfc-editor.org/info/rfc4606>.
[RFC4802] Nadeau, T., Ed. and A. Farrel, Ed., "Generalized
Multiprotocol Label Switching (GMPLS) Traffic Engineering
Management Information Base", RFC 4802,
DOI 10.17487/RFC4802, February 2007,
<https://www.rfc-editor.org/info/rfc4802>.
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[RFC4872] Lang, J., Ed., Rekhter, Y., Ed., and D. Papadimitriou,
Ed., "RSVP-TE Extensions in Support of End-to-End
Generalized Multi-Protocol Label Switching (GMPLS)
Recovery", RFC 4872, DOI 10.17487/RFC4872, May 2007,
<https://www.rfc-editor.org/info/rfc4872>.
[RFC4873] Berger, L., Bryskin, I., Papadimitriou, D., and A. Farrel,
"GMPLS Segment Recovery", RFC 4873, DOI 10.17487/RFC4873,
May 2007, <https://www.rfc-editor.org/info/rfc4873>.
[RFC5088] Le Roux, JL., Ed., Vasseur, JP., Ed., Ikejiri, Y., and R.
Zhang, "OSPF Protocol Extensions for Path Computation
Element (PCE) Discovery", RFC 5088, DOI 10.17487/RFC5088,
January 2008, <https://www.rfc-editor.org/info/rfc5088>.
[RFC5089] Le Roux, JL., Ed., Vasseur, JP., Ed., Ikejiri, Y., and R.
Zhang, "IS-IS Protocol Extensions for Path Computation
Element (PCE) Discovery", RFC 5089, DOI 10.17487/RFC5089,
January 2008, <https://www.rfc-editor.org/info/rfc5089>.
[RFC5440] Vasseur, JP., Ed. and JL. Le Roux, Ed., "Path Computation
Element (PCE) Communication Protocol (PCEP)", RFC 5440,
DOI 10.17487/RFC5440, March 2009,
<https://www.rfc-editor.org/info/rfc5440>.
[RFC5511] Farrel, A., "Routing Backus-Naur Form (RBNF): A Syntax
Used to Form Encoding Rules in Various Routing Protocol
Specifications", RFC 5511, DOI 10.17487/RFC5511, April
2009, <https://www.rfc-editor.org/info/rfc5511>.
[RFC5520] Bradford, R., Ed., Vasseur, JP., and A. Farrel,
"Preserving Topology Confidentiality in Inter-Domain Path
Computation Using a Path-Key-Based Mechanism", RFC 5520,
DOI 10.17487/RFC5520, April 2009,
<https://www.rfc-editor.org/info/rfc5520>.
[RFC5521] Oki, E., Takeda, T., and A. Farrel, "Extensions to the
Path Computation Element Communication Protocol (PCEP) for
Route Exclusions", RFC 5521, DOI 10.17487/RFC5521, April
2009, <https://www.rfc-editor.org/info/rfc5521>.
[RFC5541] Le Roux, JL., Vasseur, JP., and Y. Lee, "Encoding of
Objective Functions in the Path Computation Element
Communication Protocol (PCEP)", RFC 5541,
DOI 10.17487/RFC5541, June 2009,
<https://www.rfc-editor.org/info/rfc5541>.
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[RFC6001] Papadimitriou, D., Vigoureux, M., Shiomoto, K., Brungard,
D., and JL. Le Roux, "Generalized MPLS (GMPLS) Protocol
Extensions for Multi-Layer and Multi-Region Networks (MLN/
MRN)", RFC 6001, DOI 10.17487/RFC6001, October 2010,
<https://www.rfc-editor.org/info/rfc6001>.
[RFC6003] Papadimitriou, D., "Ethernet Traffic Parameters",
RFC 6003, DOI 10.17487/RFC6003, October 2010,
<https://www.rfc-editor.org/info/rfc6003>.
[RFC6205] Otani, T., Ed. and D. Li, Ed., "Generalized Labels for
Lambda-Switch-Capable (LSC) Label Switching Routers",
RFC 6205, DOI 10.17487/RFC6205, March 2011,
<https://www.rfc-editor.org/info/rfc6205>.
[RFC6387] Takacs, A., Berger, L., Caviglia, D., Fedyk, D., and J.
Meuric, "GMPLS Asymmetric Bandwidth Bidirectional Label
Switched Paths (LSPs)", RFC 6387, DOI 10.17487/RFC6387,
September 2011, <https://www.rfc-editor.org/info/rfc6387>.
[RFC7139] Zhang, F., Ed., Zhang, G., Belotti, S., Ceccarelli, D.,
and K. Pithewan, "GMPLS Signaling Extensions for Control
of Evolving G.709 Optical Transport Networks", RFC 7139,
DOI 10.17487/RFC7139, March 2014,
<https://www.rfc-editor.org/info/rfc7139>.
[RFC7570] Margaria, C., Ed., Martinelli, G., Balls, S., and B.
Wright, "Label Switched Path (LSP) Attribute in the
Explicit Route Object (ERO)", RFC 7570,
DOI 10.17487/RFC7570, July 2015,
<https://www.rfc-editor.org/info/rfc7570>.
[RFC7792] Zhang, F., Zhang, X., Farrel, A., Gonzalez de Dios, O.,
and D. Ceccarelli, "RSVP-TE Signaling Extensions in
Support of Flexi-Grid Dense Wavelength Division
Multiplexing (DWDM) Networks", RFC 7792,
DOI 10.17487/RFC7792, March 2016,
<https://www.rfc-editor.org/info/rfc7792>.
[RFC8126] Cotton, M., Leiba, B., and T. Narten, "Guidelines for
Writing an IANA Considerations Section in RFCs", BCP 26,
RFC 8126, DOI 10.17487/RFC8126, June 2017,
<https://www.rfc-editor.org/info/rfc8126>.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, <https://www.rfc-editor.org/info/rfc8174>.
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[RFC8253] Lopez, D., Gonzalez de Dios, O., Wu, Q., and D. Dhody,
"PCEPS: Usage of TLS to Provide a Secure Transport for the
Path Computation Element Communication Protocol (PCEP)",
RFC 8253, DOI 10.17487/RFC8253, October 2017,
<https://www.rfc-editor.org/info/rfc8253>.
[RFC8282] Oki, E., Takeda, T., Farrel, A., and F. Zhang, "Extensions
to the Path Computation Element Communication Protocol
(PCEP) for Inter-Layer MPLS and GMPLS Traffic
Engineering", RFC 8282, DOI 10.17487/RFC8282, December
2017, <https://www.rfc-editor.org/info/rfc8282>.
[RFC8306] Zhao, Q., Dhody, D., Ed., Palleti, R., and D. King,
"Extensions to the Path Computation Element Communication
Protocol (PCEP) for Point-to-Multipoint Traffic
Engineering Label Switched Paths", RFC 8306,
DOI 10.17487/RFC8306, November 2017,
<https://www.rfc-editor.org/info/rfc8306>.
9.2. Informative References
[RFC4655] Farrel, A., Vasseur, J., and J. Ash, "A Path Computation
Element (PCE)-Based Architecture", RFC 4655,
DOI 10.17487/RFC4655, August 2006,
<https://www.rfc-editor.org/info/rfc4655>.
[RFC4657] Ash, J., Ed. and J. Le Roux, Ed., "Path Computation
Element (PCE) Communication Protocol Generic
Requirements", RFC 4657, DOI 10.17487/RFC4657, September
2006, <https://www.rfc-editor.org/info/rfc4657>.
[RFC5920] Fang, L., Ed., "Security Framework for MPLS and GMPLS
Networks", RFC 5920, DOI 10.17487/RFC5920, July 2010,
<https://www.rfc-editor.org/info/rfc5920>.
[RFC6123] Farrel, A., "Inclusion of Manageability Sections in Path
Computation Element (PCE) Working Group Drafts", RFC 6123,
DOI 10.17487/RFC6123, February 2011,
<https://www.rfc-editor.org/info/rfc6123>.
[RFC6163] Lee, Y., Ed., Bernstein, G., Ed., and W. Imajuku,
"Framework for GMPLS and Path Computation Element (PCE)
Control of Wavelength Switched Optical Networks (WSONs)",
RFC 6163, DOI 10.17487/RFC6163, April 2011,
<https://www.rfc-editor.org/info/rfc6163>.
Margaria, et al. Expires June 14, 2020 [Page 42]
Internet-Draft PCEP Ext for GMPLS December 2019
[RFC7025] Otani, T., Ogaki, K., Caviglia, D., Zhang, F., and C.
Margaria, "Requirements for GMPLS Applications of PCE",
RFC 7025, DOI 10.17487/RFC7025, September 2013,
<https://www.rfc-editor.org/info/rfc7025>.
[RFC7449] Lee, Y., Ed., Bernstein, G., Ed., Martensson, J., Takeda,
T., Tsuritani, T., and O. Gonzalez de Dios, "Path
Computation Element Communication Protocol (PCEP)
Requirements for Wavelength Switched Optical Network
(WSON) Routing and Wavelength Assignment", RFC 7449,
DOI 10.17487/RFC7449, February 2015,
<https://www.rfc-editor.org/info/rfc7449>.
Appendix A. LOAD-BALANCING Usage for SDH Virtual Concatenation
For example a request for one co-signaled n x VC-4 TE-LSP will not
use the LOAD-BALANCING. In case the VC-4 components can use
different paths, the BANDWIDTH with object type TBA-2 will contain a
traffic specification indicating the complete n x VC-4 traffic
specification and the LOAD-BALANCING the minimum co-signaled VC-4.
For an SDH network, a request to have a TE-LSP group with 10 VC-4
containers, each path using at minimum 2 x VC-4 containers, can be
represented with a BANDWIDTH object with OT=TBA-2, Bw Spec Type set
to 4, the content of the Generalized Bandwidth is ST=6, RCC=0, NCC=0,
NVC=10, MT=1. The LOAD-BALANCING, OT=TBA-4 with Bw Spec Type set to
4, Max-LSP=5, Min Bandwidth Spec is (ST=6, RCC=0, NCC=0, NVC=2,
MT=1). The PCE can respond with a response with maximum 5 paths,
each of them having a BANDWIDTH OT=TBA-2 and Generalized Bandwidth
matching the Min Bandwidth Spec from the LOAD-BALANCING object of the
corresponding request.
Authors' Addresses
Cyril Margaria (editor)
Juniper
Email: cmargaria@juniper.net
Oscar Gonzalez de Dios (editor)
Telefonica Investigacion y Desarrollo
C/ Ronda de la Comunicacion
Madrid 28050
Spain
Phone: +34 91 4833441
Email: oscar.gonzalezdedios@telefonica.com
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Internet-Draft PCEP Ext for GMPLS December 2019
Fatai Zhang (editor)
Huawei Technologies
F3-5-B R&D Center, Huawei Base
Bantian, Longgang District
Shenzhen 518129
P.R.China
Email: zhangfatai@huawei.com
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