PCEP extensions for GMPLS
draft-ietf-pce-gmpls-pcep-extensions-10
The information below is for an old version of the document.
| Document | Type |
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|---|---|---|---|
| Authors | Cyril Margaria , Oscar Gonzalez de Dios , Fatai Zhang | ||
| Last updated | 2015-04-11 (Latest revision 2014-10-08) | ||
| Replaces | draft-margaria-pce-gmpls-pcep-extensions | ||
| RFC stream | Internet Engineering Task Force (IETF) | ||
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draft-ietf-pce-gmpls-pcep-extensions-10
Network Working Group C. Margaria, Ed.
Internet-Draft
Intended status: Standards Track O. Gonzalez de Dios, Ed.
Expires: April 9, 2015 Telefonica Investigacion y Desarrollo
F. Zhang, Ed.
Huawei Technologies
October 06, 2014
PCEP extensions for GMPLS
draft-ietf-pce-gmpls-pcep-extensions-10
Abstract
This memo provides extensions for the Path Computation Element
communication Protocol (PCEP) for the support of GMPLS control plane.
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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Task Force (IETF). Note that other groups may also distribute
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material or to cite them other than as "work in progress."
This Internet-Draft will expire on April 9, 2015.
Copyright Notice
Copyright (c) 2014 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
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described in the Simplified BSD License.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1. Contributing Authors . . . . . . . . . . . . . . . . . . 3
1.2. PCEP requirements for GMPLS . . . . . . . . . . . . . . . 3
1.3. Current GMPLS support and limitation of existing PCEP
objects . . . . . . . . . . . . . . . . . . . . . . . . . 4
1.4. Requirements Language . . . . . . . . . . . . . . . . . . 5
2. PCEP objects and extensions . . . . . . . . . . . . . . . . . 6
2.1. GMPLS capability advertisement . . . . . . . . . . . . . 6
2.1.1. GMPLS Computation TLV in the Existing PCE Discovery
Protocol . . . . . . . . . . . . . . . . . . . . . . 6
2.1.2. OPEN Object extension GMPLS-CAPABILITY TLV . . . . . 6
2.2. RP object extension . . . . . . . . . . . . . . . . . . . 7
2.3. BANDWIDTH object extensions . . . . . . . . . . . . . . . 7
2.4. LOAD-BALANCING object extensions . . . . . . . . . . . . 9
2.5. END-POINTS Object extensions . . . . . . . . . . . . . . 12
2.5.1. Generalized Endpoint Object Type . . . . . . . . . . 13
2.5.2. END-POINTS TLVs extensions . . . . . . . . . . . . . 16
2.6. IRO extension . . . . . . . . . . . . . . . . . . . . . . 19
2.7. XRO extension . . . . . . . . . . . . . . . . . . . . . . 20
2.8. LSPA extensions . . . . . . . . . . . . . . . . . . . . . 21
2.9. NO-PATH Object Extension . . . . . . . . . . . . . . . . 22
2.9.1. Extensions to NO-PATH-VECTOR TLV . . . . . . . . . . 22
3. Additional Error Type and Error Values Defined . . . . . . . 23
4. Manageability Considerations . . . . . . . . . . . . . . . . 24
4.1. Control of Function through Configuration and Policy . . 25
4.2. Information and Data Models . . . . . . . . . . . . . . . 25
4.3. Liveness Detection and Monitoring . . . . . . . . . . . . 25
4.4. Verifying Correct Operation . . . . . . . . . . . . . . . 25
4.5. Requirements on Other Protocols and Functional Components 26
4.6. Impact on Network Operation . . . . . . . . . . . . . . . 26
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 26
5.1. PCEP Objects . . . . . . . . . . . . . . . . . . . . . . 26
5.2. END-POINTS object, Object Type Generalized Endpoint . . . 27
5.3. New PCEP TLVs . . . . . . . . . . . . . . . . . . . . . . 28
5.4. RP Object Flag Field . . . . . . . . . . . . . . . . . . 29
5.5. New PCEP Error Codes . . . . . . . . . . . . . . . . . . 29
5.6. New NO-PATH-VECTOR TLV Fields . . . . . . . . . . . . . 30
5.7. New Subobject for the Include Route Object . . . . . . . 31
5.8. New Subobject for the Exclude Route Object . . . . . . . 31
6. Security Considerations . . . . . . . . . . . . . . . . . . . 31
7. Contributing Authors . . . . . . . . . . . . . . . . . . . . 33
8. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 34
9. References . . . . . . . . . . . . . . . . . . . . . . . . . 34
9.1. Normative References . . . . . . . . . . . . . . . . . . 34
9.2. Informative References . . . . . . . . . . . . . . . . . 36
9.3. Experimental References . . . . . . . . . . . . . . . . . 37
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Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 37
1. Introduction
Although [RFC4655] defines the PCE architecture and framework for
both MPLS and GMPLS networks, current 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 OTN and WSON networks.
The functional requirements to be considered by the PCEP extensions
to support those application are described in [RFC7025] and
[I-D.ietf-pce-wson-routing-wavelength].
1.1. Contributing Authors
Elie Sfeir, Franz Rambach (Nokia Siemens Networks) Francisco Javier
Jimenez Chico (Telefonica Investigacion y Desarrollo) Suresh BR,
Young Lee, SenthilKumar S, Jun Sun (Huawei Technologies), Ramon
Casellas (CTTC)
1.2. PCEP requirements for GMPLS
The document [RFC7025] describes the set of PCEP requirements to
support GMPLS TE-LSPs. When a PCC requests a PCE to perform a path
computation (by means of a PCReq message), the PCC should be able to
indicate the following additional information:
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 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 (Resource Reservation Protocol - Traffic Engineering).
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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.
We describe in this document a set of PCEP protocol extensions,
including new object types, TLVs, encodings, error codes and
procedures, in order to fulfill the aforementioned requirements.
1.3. Current GMPLS support and limitation of existing PCEP objects
PCEP as of [RFC5440], [RFC5521] and [I-D.ietf-pce-inter-layer-ext],
supports the following objects, included in requests and responses
related to the described requirements.
From [RFC5440]:
o END-POINTS: only numbered endpoints are considered. The context
specifies whether they are node identifiers or numbered
interfaces.
o BANDWIDTH: 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 any GMPLS networks.
o ERO : Unnumbered endpoints are supported.
o LSPA: LSP attributes (setup and holding priorities)
From [RFC5521] :
o XRO object :
* This object allows excluding (strict or not) resources, and
includes the requested diversity (node, link or SRLG).
* When the F bit is set, the request indicates that the existing
route has failed and the resources present in the RRO can be
reused.
From [I-D.ietf-pce-inter-layer-ext]:
o INTER-LAYER : indicates whether inter-layer computation is allowed
o SWITCH-LAYER : indicates which layer(s) should be considered, can
be used to represent the RSVP-TE generalized label request
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o REQ-ADAP-CAP : indicates the adaptation capabilities requested,
can also be used for the endpoints in case of mono-layer
computation
The shortcomings of the existing PCEP object are:
The BANDWIDTH and LOAD-BALANCING objects do not describe the
details of the traffic request (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.
Those parameters are of interest in case of switching constraints.
The IRO/XRO objects do not allow the inclusion/exclusion of labels
Current attributes do not allow expressing the requested link
protection level and/or the end-to-end protection attributes.
The covered PCEP extensions are:
Two new object types are introduced for the BANDWIDTH
object(Generalized-Bandwidth, Generalized Bandwidth of existing
TE-LSP).
A new object type is introduced for the LOAD-BALANCING object
(Generalized LOAD-BALANCING).
A new object type is introduced 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.
A new TLV type for label is allowed in IRO and XRO objects.
In order to indicate the used routing granularity in the response,
a new flag in the RP object is added.
1.4. 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 RFC 2119 [RFC2119].
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2. PCEP objects and extensions
This section describes the required 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 can be used to detect
GMPLS-capable PCEs.
2.1.2. OPEN Object extension GMPLS-CAPABILITY TLV
In addition to the IGP advertisement, a PCEP speaker should 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 new optional GMPLS-CAPABILITY TLV for use in
the OPEN object to negotiate the GMPLS capability. The inclusion of
this TLV in the OPEN message indicates that the PCC/PCE support the
PCEP extensions defined in the document. A PCE that is able to
support the GMPLS extensions defined in this document SHOULD include
the GMPLS-CAPABILITY TLV on the OPEN message. If the PCE does not
include the GMPLS-CAPABILITY TLV in the OPEN message and PCC does
include the TLV, it is RECOMMENDED that the PCC indicates a mismatch
of capabilities. Moreover , in case that the PCC does not receive
the GMPLS-CAPABILITY TLV it is RECOMMENDED that the PCC does not make
use of the objects and TLVs defined in this document.
IANA has allocated value TBA 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=14 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Flags |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
No Flags are defined in this document, they are reserved for future
use.
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2.2. RP object extension
Explicit label control (ELC) is a procedure supported by RSVP-TE,
where the outgoing label(s) is(are) encoded in the ERO. In
consequence, the PCE may be able to provide such label(s) directly in
the path ERO. The PCC, depending on policies or switching layer, may
be required to use explicit label control or expect explicit link,
thus it need to indicate in the PCReq which granularity it is
expecting in the ERO. This correspond 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 is defined in the RP
object. The values are defined as follows
0 : reserved
1 : node
2 : link
3 : label
The flag in the RP object indicates the requested route granularity.
The PCE MAY try to follow this granularity and MAY return a NO-PATH
if the requested granularity cannot be provided. The PCE MAY return
any granularity it likes 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 MAY 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 request 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 should be extended
to allow to express the bandwidth as described in [RFC7025]. RSVP-TE
extensions for GMPLS provide a set of encoding allowing such
representation in an unambiguous way, this is encoded in the RSVP-TE
TSpec and FlowSpec objects. This document extends the BANDIDTH
object with new object types reusing the RSVP-TE encoding.
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The following possibilities should be supported by the new 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 correspond to requirement 3, 4, 5 and 11 of [RFC7025] section
3.1.
This document defines two Object Types for the BANDWIDTH object:
TBA Requested generalized bandwidth
TBA Generalized bandwidth of an existing TE LSP for which a
reoptimization is requested
The definitions below apply for Object Type TBA and TBA. The payload
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 and TBA have a variable length. The 16
bit bandwidth spec length field indicates the length of the bandwidth
spec 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 bandwidth spec field. The reverse bandwidth
spec length MAY be equal to 0.
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The Bw Spec Type field determines which type of bandwidth is
represented by the object.
The Bw Spec Type correspond to the RSVPT-TE SENDER_TSPEC (Object
Class 12) C-Types
The encoding of the field generalized bandwidth and reverse
generalized bandwidth is the same as in RSVP-TE, it can be found in
the following references.
Object Type Name Reference
2 Intserv [RFC2210]
4 SONET/SDH [RFC4606]
5 G.709 [RFC4328]
6 Ethernet [RFC6003]
Traffic Spec field encoding
When a PCC requests a bi-directional path with symetric bandwidth, it
MUST specify the generalized bandwidth field, MUST NOT specify the
reverse generalized bandwidth and MUST 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 procedures 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 MAY be used instead of object type 2 to
indicate the existing TE-LSP bandwidth. A PCC that requested a path
with a BANDWIDTH object of object type 1 SHOULD 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 and
TBA are defined by this document.
2.4. LOAD-BALANCING object extensions
The LOAD-BALANCING object [RFC5440] is used to request a set of
maximum Max-LSP TE-LSP having in total the bandwidth specified in
BANDWIDTH, each TE-LSP having a minimum of bandwidth. The LOAD-
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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. A PCC
should be allowed to request a set of TE-LSP also in case of GMPLS
bandwidth specification.
The LOAD-BALANCING has the same limitation as the BANDWIDTH for GMPLS
networks. 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
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 specification. It should be noted that the RSVP-TE traffic
specification may also include TLV different than the PCEP TLVs. The
length MUST be strictly greater than 0.
Reverse bandwidth spec length (16 bits): the total length of the
reverse min bandwidth specification. It MAY be equal to 0.
Bw Spec Type (8 bits) : the bandwidth specification type, it
correspond to the RSVPT-TE SENDER_TSPEC (Object Class 12) C-Types
Max-LSP (8 bits): maximum number of TE LSPs in the set.
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Min Bandwidth spec (variable): Specifies the minimum bandwidth spec
of each element of the set of TE LSPs.
Min Reverse Bandwidth spec (variable): Specifies the minimum reverse
bandwidth spec of each element of the set of TE LSPs.
The encoding of the field Min Bandwidth Spec and Min Reverse
Bandwidth spec is the same as in RSVP-TE SENDER_TSPEC object, it can
be found in the following references.
Object Type Name Reference
2 Intserv [RFC2210]
4 SONET/SDH [RFC4606]
5 G.709 [RFC4328]
6 Ethernet [RFC6003]
Traffic Spec field encoding
When a PCC requests a bi-directional path with symetric bandwidth
while specifying load balancing constraints it MUST specify the min
Bandwidth spec field, MUST NOT specify the min reverse bandwidth and
MUST 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 SHOULD specify the
different bandwidth in forward and reverse directions through a min
Bandwidth spec and min reverse bandwidth 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 so that the total of
their generalized bandwidth is X, the maximum number of TE LSPs is N,
and each TE LSP must at least have a bandwidth of B, it inserts a
BANDWIDTH object specifying X as the required bandwidth and a LOAD-
BALANCING object with the Max-LSP and Min-traffic spec fields set to
N and B, respectively.
For example a request for one co-signaled n x VC-4 TE-LSP will not
use the LOAD-BALANCING. In case the V4 components can use different
paths, the BANDWIDTH with object type 3 will contain a traffic
specification indicating the complete n x VC4 traffic specification
and the LOAD-BALANCING the minimum co-signaled VC4. For a SDH
network, a request to have a TE-LSP group with 10 VC4 container, each
path using at minimum 2 x VC4 container, can be represented with a
BANDWIDTH object with OT=3, Bandwidth spec type set to 4, the content
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of the bandwidth specification is ST=6,RCC=0,NCC=0,NVC=10,MT=1. The
LOAD-BALANCING, OT=2 with Bandwidth spec set to 4,Max-LSP=5, min
Traffic spec is (ST=6,RCC=0,NCC=0,NVC=2,MT=1). The PCE can respond
with a response with maximum 5 path, each of them having a BANDWIDTH
OT=3 and traffic spec matching the minimum traffic spec from the
LOAD-BALANCING object of the corresponding request.
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.
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 label(s) associated to them, specifying a set of constraints
in the allocation of labels.
o May 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 new C-Type also supports the specification of constraints on the
endpoint label to be use. The PCE might know the interface
restrictions but this is not a requirement. This corresponds to
requirements 6 and 10 of [RFC7025].
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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 type 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 restriction.
6. Suggested label set restriction.
The Label Set and Suggested label set TLVs are used to restrict the
label allocation in the PCE. Those TLVs express the set of
restrictions provided by signaling. Label restriction support can be
an explicit value (Label set describing one label), mandatory range
restrictions (Label set), optional range restriction (suggested label
set) and single suggested value is using the suggested label set.
Endpoints label restriction may not be part of the RRO or IRO, they
may be included when following [RFC4003] in signaling for egress
endpoint, but ingress endpoint properties may be local to the PCC and
not signaled. To support this case the label set allows to indicate
which label are used in case of reoptimization. The label range
restrictions are valid in GMPLS 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 sender and receivers are limited in
their frequency tunability ranges, restricting then in GMPLS the
possible label ranges on the interface. The END-POINTS Object with
Generalized Endpoint object type is encoded as follow:
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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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| 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 must be
left unchanged
5-244 Reserved
245-255 Experimental range
The endpoint type is used to cover both point-to-point and different
point-to-multipoint endpoints. Endpoint type 0 MAY be accepted by
the PCE, other endpoint type MAY be supported if the PCE
implementation supports P2MP path calculation. A PCE not supporting
a given endpoint type MUST respond with a PCErr with error code "Path
computation failure", error type "Unsupported endpoint type in END-
POINTS Generalized Endpoint object type". The TLVs present in the
request object body MUST follow the following grammar:
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<generalized-endpoint-tlvs>::=
<p2p-endpoints> | <p2mp-endpoints>
<p2p-endpoints> ::=
<source-endpoint>
<destination-endpoint>
<source-endpoint> ::=
<endpoint>
[<endpoint-restriction-list>]
<destination-endpoint> ::=
<endpoint>
[<endpoint-restriction-list>]
<p2mp-endpoints> ::=
<endpoint> [<endpoint-restriction-list>]
[<endpoint> [<endpoint-restriction-list>]]...
For endpoint type Point-to-Multipoint, several endpoint objects may
be present in the message and each represents a leave, exact meaning
depend on the endpoint type defined of the object.
An endpoint is defined as follows:
<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>|
<SUGGESTED-LABEL-SET>
The different TLVs are described in the following sections. A PCE
MAY support IPV4-ADDRESS,IPV6-ADDRESS or UNNUMBERED-ENDPOINT TLV. A
PCE not supporting one of those TLVs in a PCReq MUST respond with a
PCRep with NO-PATH with the bit "Unknown destination" or "Unknown
source" in the NO-PATH-VECTOR TLV, the response SHOULD include the
ENDPOINT object in the response with only the TLV it did not
understood.
A PCE MAY support LABEL-REQUEST, LABEL-SET or SUGGESTED-LABEL-SET
TLV. If a PCE finds a non-supported TLV in the END-POINTS the PCE
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MUST respond with a PCErr message with error type="Path computation
failure" error value="Unsupported TLV present in END-POINTS
Generalized Endpoint object type" and the message SHOULD include the
ENDPOINT 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 ENDPOINT object
containing only the TLV where the PCE could not meet the constraint.
2.5.2. END-POINTS TLVs extensions
All endpoint TLVs have the standard PCEP TLV header as defined in
[RFC5440] section 7.1. In this object type the order of the TLVs
MUST be followed according to the object type definition.
2.5.2.1. IPV4-ADDRESS
This TLV represent a numbered endpoint using IPv4 numbering, the
format of the IPv4-ADDRESS TLV value (TLV-Type=TBA) 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IPv4 address |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
This TLV MAY be ignored, in which case a PCRep with NO-PATH should be
responded, as described in Section 2.5.1.
2.5.2.2. IPV6-ADDRESS TLV
This TLV represent a numbered endpoint using IPV6 numbering, the
format of the IPv6-ADDRESS TLV value (TLV-Type=TBA) 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
responded, as described in Section 2.5.1.
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2.5.2.3. UNNUMBERED-ENDPOINT TLV
This TLV represent an unnumbered interface. This TLV has the same
semantic as in [RFC3477] The TLV value is encoded as follow (TLV-
Type=TBA)
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
responded, 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. Its
format and encoding is the same as described in [RFC3471] Section 3.1
Generalized label request. The LABEL-REQUEST TLV use TLV-Type=TBA.
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 introduced to satisfy requirement 13 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 Tspec and switch layer need
to be coherent, the endpoint labels could be different (supporting a
different Tspec). 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 responded, as
described in Section 2.5.1.
2.5.2.5. Labels TLV
Label or label range restrictions may 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
[I-D.ietf-pce-inter-layer-ext] can be used in case of mono-layer
request, however in case of multilayer it is possible to have in the
future more than one object, so it is better to have a dedicated TLV
for the label and label request (the scope is then more clear).
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Those TLV MAY be ignored, in which case a response with NO-PATH
should be responded, as described in Section 2.5.1. TLVs are encoded
as follow (following [RFC5440]) :
o LABEL-SET TLV, Type=TBA. The TLV Length is variable, Encoding
follows [RFC3471] Section 3.5 "Label set" with the addition of a U
bit and O Bit. The U bit is set for upstream direction in case of
bidirectional LSP and the O bit is used to represent an old label.
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 |O|U| Label Type |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Subchannel 1 |
| ... |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
: : :
: : :
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Subchannel N |
| ... |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
o SUGGESTED-LABEL-SET TLV Set, Type=TBA. The TLV length is variable
and its encoding is as LABEL-SET TLV. The 0 bit SHOULD be set to
0.
A LABEL-SET TLV represents a set of possible labels that can be used
on an interface. The label allocated on the first link SHOULD be
within the label set range. The action parameter in the Label set
indicates the type of list provided. Those parameters are described
by [RFC3471] section 3.5.1 A SUGGESTED-LABEL-SET TLV has the same
encoding as the LABEL-SET TLV, it indicates to the PCE a set of
preferred (ordered) set of labels to be used. The PCE MAY use those
labels for label allocation.
The U and 0 bits have the following meaning:
U: Upstream direction: set when the label or label set is in the
reverse direction
O: Old Label: set when the TLV represent the old label in case of re-
optimization. This Bit SHOULD be set to 0 in a SUGGESTED-LABEL-SET
TLV Set and ignored on receipt. This Label MAY be reused. The R
bit of the RP object MUST be set. When this bit is set the Action
field MUST be set to 0 (Inclusive List) and the Label Set MUST
contain one subchannel.
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Several LABEL_SET TLVs MAY be present with the 0 bit cleared. At
most 2 LABEL_SET TLV SHOULD be present with the 0 bit set, at most
one with the U bit set and at most 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 SHOULD be processed and the following TLV
with the same U and O bit SHOULD be ignored.
A SUGGESTED-LABEL-SET TLV with the O bit set MUST trigger a PCErr
message with error type="Reception of an invalid object" error
value="Wrong LABEL-SET or SUGGESTED-LABEL-SET TLV present with 0 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="Reception of an invalid object"
error value="Wrong LABEL-SET or SUGGESTED-LABEL-SET TLV present with
0 bit set".
If a LABEL-SET TLV is present with O bit set, the R bit of the RP
object MUST be set or a PCErr message with error type="Reception of
an invalid object" error value="LABEL-SET TLV present with 0 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 to include label definition, in order to
fulfill requirement 13 the IRO should support the new subobject type
as defined in [RFC3473]:
Type Sub-object
TBA, recommended value 3 LABEL
The L bit of such sub-object has no meaning within an IRO.
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 IP
address given 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 allocates 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.
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2.7. XRO extension
The XRO as defined in [RFC5521] is used to exclude specific objects
in the path. RSVP-TE allows to exclude labels ([RFC6001], in order
to fulfill requirement 13 of [RFC7025] section 3.1, the XRO should
support a new subobject to support 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
[RFC5521]. The XRO Label subobject represent one Label and is
defined as follows:
XRO Subobject Type TBA, recommended value 3: 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=3 | 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, recommended value
3.
Length (8 bits)
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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].
C-Type (8 bits)
The C-Type of the included Label Object as defined in
[RFC3471].
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 IP
address given MUST be associated with a link. More than one label
subobject MAY follow each link subobject.
Type Sub-object
3 LABEL
The L bit of such sub-object has no meaning within an XRO.
2.8. LSPA extensions
The LSPA carries the LSP attributes. In the end-to-end protection
context this also includes the protection state information. This
object is introduced to fulfill requirement 7 of [RFC7025] section
3.1 and requirement 3 of [RFC7025] section 3.2. This object contains
the information of the PROTECTION object defined by [RFC4872] and
may be used as a policy input. The LSPA object MAY carry a
PROTECTION-ATTRIBUTE TLV defined as : Type TBA: PROTECTION-ATTRIBUTE
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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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| 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], [RFC4873].
LSP (protection) Flags or Link flags field can be used by
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, in which case it
MUST NOT include the TLV in the LSPA, if present, 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 carries 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 more additional constraints that led to the
failure like protection mismatch, lack of resources, and so on. Few
new flags have been introduced in the 32-bit flag field of the NO-
PATH-VECTOR TLV and no modifications have been made in the NO-PATH
object.
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 - Protection Mismatch (1-bit). Specifies the
mismatch of the protection type in the PROTECTION-ATTRIBUTE TLV in
the request.
Bit number TBA - No Resource (1-bit). Specifies that the
resources are not currently sufficient to provide the path.
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Bit number TBA - Granularity not supported (1-bit). Specifies
that the PCE is not able to provide a route with the requested
granularity.
Bit number TBA - No endpoint label resource (1-bit). Specifies
that the PCE is not able to provide a route because of the
endpoint label restriction.
Bit number TBA - No endpoint label resource in range (1-bit).
Specifies that the PCE is not able to provide a route because of
the endpoint label set restriction.
Bit number TBA - No label resource in range (1-bit). Specifies
that the PCE is not able to provide a route because of the label
set restriction.
3. Additional Error Type 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 few 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-Type 10
and A new Error-Type is introduced (value TBA).
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Error-Type Error-value
10 Reception of
an invalid
object
value=TBA: Bad Bandwidth Object type TBA(Generalized
bandwidth) or TBA(Generalized
bandwidth,reoptimization).
value=TBA: Bandwidth Object type TBA or TBA not
supported.
value=TBA: Unsupported LSP Protection Type in
PROTECTION-ATTRIBUTE TLV.
value=TBA: Unsupported LSP Protection Flags in
PROTECTION-ATTRIBUTE TLV.
value=TBA: Unsupported Secondary LSP Protection Flags
in PROTECTION-ATTRIBUTE TLV.
value=TBA: Unsupported Link Protection Type in
PROTECTION-ATTRIBUTE TLV.
value=TBA: Unsupported Link Protection Type in
PROTECTION-ATTRIBUTE TLV.
value=TBA: LABEL-SET TLV present with 0 bit set but
without R bit set in RP.
value=TBA: Wrong LABEL-SET or
SUGGESTED-LABEL-SET TLV present with
0 bit set.
TBA Path
computation
failure
value=TBA: Unacceptable request message.
value=TBA: Generalized bandwidth value not supported.
value=TBA: Label Set constraint could not be
met.
value=TBA: Label constraint could not be
met.
value=TBA: Unsupported endpoint type in
END-POINTS Generalized Endpoint
object type.
value=TBA: Unsupported TLV present in END-POINTS
Generalized Endpoint object type.
value=TBA: Unsupported granularity in the RP object
flags.
4. Manageability Considerations
This section follows the guidance of [RFC6123].
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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 and TBA (Generalized
Bandwidth)parameters in request, default mapping to use when not
specified in the request
Accepted LOAD-BALANCING object type TBA 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.
Those parameters configuration are 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 introduces new ERO sub object,
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.
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
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introduced by this document should be covered by 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 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 protocol objects and TLVs. IANA is
requested to make some allocations for the newly defined objects and
TLVs introduced 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 : Generalized bandwidth
TBA: Generalized bandwidth of an existing TE LSP for
which a reoptimization is requested
5-15: Unassigned
Reference This document (section Section 2.3)
Object 14
Class
Name LOAD-BALANCING
Object-Type TBA: Generalized load balancing
3-15: Unassigned
Reference This document (section Section 2.4)
Object 4
Class
Name END-POINTS
Object-Type TBA: Generalized Endpoint
6-15: unassigned
Reference This document (section Section 2.5)
5.2. END-POINTS object, Object Type Generalized Endpoint
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 may be allocated by an IETF
consensus action. Each endpoint type should be tracked with the
following qualities:
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 4):
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Value Type Meaning
TBA, recommended Point-to-Point
valude 0
TBA, recommended Point-to-Multipoint New leaves to add
valude 1
TBA, recommended Old leaves to remove
valude 2
TBA, recommended Old leaves whose path can be
valude 3 modified/reoptimized
TBA, recommended Old leaves whose path must be
valude 4
left unchanged
TBA, recommended Reserved
valude 5-244
TBA, recommended Experimental range
valude 245-255
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. This
document defines new PCEP TLVs, to be carried in the END-POINTS
object with Generalized Endpoint object Type. IANA is requested to
do the following allocation. The values here are suggested for use
by IANA.
Value Meaning Reference
TBA IPv4 endpoint This document (section Section
2.5.2.1)
TBA IPv6 endpoint This document (section Section
2.5.2.2)
TBA Unnumbered endpoint This document (section Section
2.5.2.3)
TBA Label request This document (section Section
2.5.2.4)
TBA Requested GMPLS Label This document (section Section
Set 2.5.2.5)
TBA Suggested GMPLS Label This document (section Section
Set 2.5.2.5)
TBA PROTECTION-ATTRIBUTE This document (section Section 2.8)
TBA GMPLS-CAPABILITY This document (section Section 2.1.2)
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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. The values here are
suggested for use by IANA.
Bit Description Reference
TBA (recommended bit routing granularity This document, Section
17-16) (RG) 2.2
5.5. New PCEP Error Codes
As described in Section 3, new PCEP Error-Type and Error Values are
defined. IANA is requested to make the following allocation in the
"PCEP-ERROR Object Error Types and Values" registry. The values here
are suggested for use by IANA.
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Error name Reference
Type=10 Reception of an invalid object [RFC5440]
Value=TBA: Bad Bandwidth Object type TBA(Generalized This Document
bandwidth) or TBA(Generalized
bandwidth,reoptimization).
Value=TBA: Bandwidth Object type TBA or TBA not This Document
supported.
Value=TBA: Unsupported LSP Protection Type in This Document
PROTECTION-ATTRIBUTE TLV.
Value=TBA: Unsupported LSP Protection Flags in This Document
PROTECTION-ATTRIBUTE TLV.
Value=TBA: Unsupported Secondary LSP Protection Flags This Document
in PROTECTION-ATTRIBUTE TLV.
Value=TBA: Unsupported Link Protection Type in This Document
PROTECTION-ATTRIBUTE TLV.
Value=TBA: Unsupported Link Protection Type in This Document
PROTECTION-ATTRIBUTE TLV.
Value=TBA: LABEL-SET TLV present with 0 bit set but This Document
without R bit set in RP.
Value=TBA: Wrong LABEL-SET or SUGGESTED-LABEL-SET TLV This Document
present with 0 bit set.
Type=TBA Path computation failure This Document
Value=TBA: Unacceptable request message. This Document
Value=TBA: Generalized bandwidth value not supported. This Document
Value=TBA: Label Set constraint could not be met. This Document
Value=TBA: Label constraint could not be met. This Document
Value=TBA: Unsupported endpoint type in END-POINTS This Document
Generalized Endpoint object type
Value=TBA: Unsupported TLV present in END-POINTS This Document
Generalized Endpoint object type
Value=TBA: Unsupported granularity in the RP object This Document
flags
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. The values here
are suggested for use by IANA.
Bit number TBA - Protection Mismatch (1-bit). Specifies the
mismatch of the protection type of the PROTECTION-ATTRIBUTE TLV in
the request.
Bit number TBA - No Resource (1-bit). Specifies that the
resources are not currently sufficient to provide the path.
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Bit number TBA - Granularity not supported (1-bit). Specifies
that the PCE is not able to provide a route with the requested
granularity.
Bit number TBA - No endpoint label resource (1-bit). Specifies
that the PCE is not able to provide a route because of the
endpoint label restriction.
Bit number TBA - No endpoint label resource in range (1-bit).
Specifies that the PCE is not able to provide a route because of
the endpoint label set restriction.
Bit number TBA - No label resource in range (1-bit). Specifies
that the PCE is not able to provide a route because of the label
set restriction.
5.7. New Subobject for the Include Route Object
The "PCEP Parameters" registry contains a subregistry "PCEP Objects"
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, recommended value 3 Label subobject [RFC3473]
5.8. New Subobject for the Exclude Route Object
The "PCEP Parameters" registry contains a subregistry "PCEP Objects"
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, recommended value 3 Label subobject [RFC3473]
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 amount 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
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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 may 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 requests 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 some sniffing devices could be
installed. Also, the answer 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 may look
perfectly fine, but will be in a risky situation. Also, the
answer can lead to provide a LSP that does not provide the desired
quality and gives less resources tan necessary.
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 deciphering: 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. Authentication can provide origin
verification, message integrity and replay protection, while
confidentiality ensures that a third party cannot decipher the
contents of a message.
The document [I-D.ietf-pce-pceps] 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.
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
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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
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
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SenthilKumar S
Shenzhen
China
Email: senthilkumars@huawei.com
Jun Sun
Shenzhen
China
Email: johnsun@huawei.com
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 Lyndon Ong, Giada Lander, Jonathan
Hardwick and Diego Lopez for their useful comments to the document.
9. References
9.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC2210] Wroclawski, J., "The Use of RSVP with IETF Integrated
Services", RFC 2210, September 1997.
[RFC3471] Berger, L., "Generalized Multi-Protocol Label Switching
(GMPLS) Signaling Functional Description", RFC 3471,
January 2003.
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[RFC3473] Berger, L., "Generalized Multi-Protocol Label Switching
(GMPLS) Signaling Resource ReserVation Protocol-Traffic
Engineering (RSVP-TE) Extensions", RFC 3473, January 2003.
[RFC3477] Kompella, K. and Y. Rekhter, "Signalling Unnumbered Links
in Resource ReSerVation Protocol - Traffic Engineering
(RSVP-TE)", RFC 3477, January 2003.
[RFC4003] Berger, L., "GMPLS Signaling Procedure for Egress
Control", RFC 4003, February 2005.
[RFC4328] Papadimitriou, D., "Generalized Multi-Protocol Label
Switching (GMPLS) Signaling Extensions for G.709 Optical
Transport Networks Control", RFC 4328, January 2006.
[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, August 2006.
[RFC4802] Nadeau, T. and A. Farrel, "Generalized Multiprotocol Label
Switching (GMPLS) Traffic Engineering Management
Information Base", RFC 4802, February 2007.
[RFC4872] Lang, J., Rekhter, Y., and D. Papadimitriou, "RSVP-TE
Extensions in Support of End-to-End Generalized Multi-
Protocol Label Switching (GMPLS) Recovery", RFC 4872, May
2007.
[RFC4873] Berger, L., Bryskin, I., Papadimitriou, D., and A. Farrel,
"GMPLS Segment Recovery", RFC 4873, May 2007.
[RFC5088] Le Roux, JL., Vasseur, JP., Ikejiri, Y., and R. Zhang,
"OSPF Protocol Extensions for Path Computation Element
(PCE) Discovery", RFC 5088, January 2008.
[RFC5089] Le Roux, JL., Vasseur, JP., Ikejiri, Y., and R. Zhang,
"IS-IS Protocol Extensions for Path Computation Element
(PCE) Discovery", RFC 5089, January 2008.
[RFC5440] Vasseur, JP. and JL. Le Roux, "Path Computation Element
(PCE) Communication Protocol (PCEP)", RFC 5440, March
2009.
[RFC5520] Bradford, R., Vasseur, JP., and A. Farrel, "Preserving
Topology Confidentiality in Inter-Domain Path Computation
Using a Path-Key-Based Mechanism", RFC 5520, April 2009.
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[RFC5521] Oki, E., Takeda, T., and A. Farrel, "Extensions to the
Path Computation Element Communication Protocol (PCEP) for
Route Exclusions", RFC 5521, April 2009.
[RFC5541] Le Roux, JL., Vasseur, JP., and Y. Lee, "Encoding of
Objective Functions in the Path Computation Element
Communication Protocol (PCEP)", RFC 5541, June 2009.
[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, October 2010.
[RFC6003] Papadimitriou, D., "Ethernet Traffic Parameters", RFC
6003, October 2010.
[RFC6205] Otani, T. and D. Li, "Generalized Labels for Lambda-
Switch-Capable (LSC) Label Switching Routers", RFC 6205,
March 2011.
[RFC6387] Takacs, A., Berger, L., Caviglia, D., Fedyk, D., and J.
Meuric, "GMPLS Asymmetric Bandwidth Bidirectional Label
Switched Paths (LSPs)", RFC 6387, September 2011.
9.2. Informative References
[I-D.ietf-pce-inter-layer-ext]
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", draft-ietf-pce-inter-layer-ext-08 (work in
progress), January 2014.
[I-D.ietf-pce-wson-routing-wavelength]
Lee, Y., Bernstein, G., Martensson, J., Takeda, T.,
Tsuritani, T., and O. Dios, "PCEP Requirements for WSON
Routing and Wavelength Assignment", draft-ietf-pce-wson-
routing-wavelength-13 (work in progress), August 2014.
[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.
[RFC5920] Fang, L., "Security Framework for MPLS and GMPLS
Networks", RFC 5920, July 2010.
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[RFC6123] Farrel, A., "Inclusion of Manageability Sections in Path
Computation Element (PCE) Working Group Drafts", RFC 6123,
February 2011.
[RFC7025] Otani, T., Ogaki, K., Caviglia, D., Zhang, F., and C.
Margaria, "Requirements for GMPLS Applications of PCE",
RFC 7025, September 2013.
9.3. Experimental References
[I-D.ietf-pce-pceps]
Lopez, D., Dios, O., Wu, W., and D. Dhody, "Secure
Transport for PCEP", draft-ietf-pce-pceps-02 (work in
progress), October 2014.
Authors' Addresses
Cyril Margaria (editor)
145 Valley Road
Princeton, NJ 08540
USA
Email: cyril.margaria@gmail.com
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
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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