draft-ietf-pce-pcep-domain-sequence-09.txt   draft-ietf-pce-pcep-domain-sequence-10.txt 
PCE Working Group D. Dhody PCE Working Group D. Dhody
Internet-Draft U. Palle Internet-Draft U. Palle
Intended status: Experimental Huawei Technologies Intended status: Experimental Huawei Technologies
Expires: March 23, 2016 R. Casellas Expires: May 22, 2016 R. Casellas
CTTC CTTC
September 20, 2015 November 19, 2015
Standard Representation of Domain-Sequence Domain Subobjects for Path Computation Element (PCE) Communication
draft-ietf-pce-pcep-domain-sequence-09 Protocol (PCEP).
draft-ietf-pce-pcep-domain-sequence-10
Abstract Abstract
The ability to compute shortest constrained Traffic Engineering Label The ability to compute shortest constrained Traffic Engineering Label
Switched Paths (TE LSPs) in Multiprotocol Label Switching (MPLS) and Switched Paths (TE LSPs) in Multiprotocol Label Switching (MPLS) and
Generalized MPLS (GMPLS) networks across multiple domains has been Generalized MPLS (GMPLS) networks across multiple domains has been
identified as a key requirement. In this context, a domain is a identified as a key requirement. In this context, a domain is a
collection of network elements within a common sphere of address collection of network elements within a common sphere of address
management or path computational responsibility such as an Interior management or path computational responsibility such as an Interior
Gateway Protocol (IGP) area or an Autonomous System (AS). This Gateway Protocol (IGP) area or an Autonomous System (AS). This
document specifies a standard representation and encoding of a document specifies a representation and encoding of a Domain-
Domain-Sequence, which is defined as an ordered sequence of domains Sequence, which is defined as an ordered sequence of domains
traversed to reach the destination domain to be used by Path traversed to reach the destination domain to be used by Path
Computation Elements (PCEs) to compute inter-domain constrained Computation Elements (PCEs) to compute inter-domain constrained
shortest paths across a predetermined sequence of domains . This shortest paths across a predetermined sequence of domains . This
document also defines new subobjects to be used to encode domain document also defines new subobjects to be used to encode domain
identifiers. identifiers.
Status of This Memo Status of This Memo
This Internet-Draft is submitted in full conformance with the This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79. provisions of BCP 78 and BCP 79.
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Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet- working documents as Internet-Drafts. The list of current Internet-
Drafts is at http://datatracker.ietf.org/drafts/current/. Drafts is at http://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress." material or to cite them other than as "work in progress."
This Internet-Draft will expire on March 23, 2016. This Internet-Draft will expire on May 22, 2016.
Copyright Notice Copyright Notice
Copyright (c) 2015 IETF Trust and the persons identified as the Copyright (c) 2015 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of (http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents publication of this document. Please review these documents
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to this document. Code Components extracted from this document must to this document. Code Components extracted from this document must
include Simplified BSD License text as described in Section 4.e of include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License. described in the Simplified BSD License.
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1. Scope . . . . . . . . . . . . . . . . . . . . . . . . . . 4 1.1. Scope . . . . . . . . . . . . . . . . . . . . . . . . . . 4
1.2. Requirements Language . . . . . . . . . . . . . . . . . . 4 1.2. Requirements Language . . . . . . . . . . . . . . . . . . 4
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 5
3. Detail Description . . . . . . . . . . . . . . . . . . . . . 6 3. Detail Description . . . . . . . . . . . . . . . . . . . . . 6
3.1. Domains . . . . . . . . . . . . . . . . . . . . . . . . . 6 3.1. Domains . . . . . . . . . . . . . . . . . . . . . . . . . 6
3.2. Domain-Sequence . . . . . . . . . . . . . . . . . . . . . 6 3.2. Domain-Sequence . . . . . . . . . . . . . . . . . . . . . 6
3.3. Domain-Sequence Representation . . . . . . . . . . . . . 7 3.3. Domain-Sequence Representation . . . . . . . . . . . . . 7
3.4. Include Route Object (IRO) . . . . . . . . . . . . . . . 7 3.4. Include Route Object (IRO) . . . . . . . . . . . . . . . 7
3.4.1. Subobjects . . . . . . . . . . . . . . . . . . . . . 8 3.4.1. Subobjects . . . . . . . . . . . . . . . . . . . . . 8
3.4.1.1. Autonomous system . . . . . . . . . . . . . . . . 8 3.4.1.1. Autonomous system . . . . . . . . . . . . . . . . 8
3.4.1.2. IGP Area . . . . . . . . . . . . . . . . . . . . 9 3.4.1.2. IGP Area . . . . . . . . . . . . . . . . . . . . 9
3.4.2. Update in IRO specification . . . . . . . . . . . . . 10 3.4.2. Update in IRO specification . . . . . . . . . . . . . 10
3.4.3. IRO for Domain-Sequence . . . . . . . . . . . . . . . 10 3.4.3. IRO for Domain-Sequence . . . . . . . . . . . . . . . 10
3.4.3.1. PCC Procedures . . . . . . . . . . . . . . . . . 11 3.4.3.1. PCC Procedures . . . . . . . . . . . . . . . . . 11
3.4.3.2. PCE Procedures . . . . . . . . . . . . . . . . . 11 3.4.3.2. PCE Procedures . . . . . . . . . . . . . . . . . 11
3.5. Exclude Route Object (XRO) . . . . . . . . . . . . . . . 12 3.5. Exclude Route Object (XRO) . . . . . . . . . . . . . . . 12
3.5.1. Subobjects . . . . . . . . . . . . . . . . . . . . . 12 3.5.1. Subobjects . . . . . . . . . . . . . . . . . . . . . 13
3.5.1.1. Autonomous system . . . . . . . . . . . . . . . . 13 3.5.1.1. Autonomous system . . . . . . . . . . . . . . . . 13
3.5.1.2. IGP Area . . . . . . . . . . . . . . . . . . . . 13 3.5.1.2. IGP Area . . . . . . . . . . . . . . . . . . . . 14
3.6. Explicit Exclusion Route Subobject (EXRS) . . . . . . . . 15 3.6. Explicit Exclusion Route Subobject (EXRS) . . . . . . . . 15
3.7. Explicit Route Object (ERO) . . . . . . . . . . . . . . . 15 3.7. Explicit Route Object (ERO) . . . . . . . . . . . . . . . 16
4. Examples . . . . . . . . . . . . . . . . . . . . . . . . . . 16 4. Examples . . . . . . . . . . . . . . . . . . . . . . . . . . 16
4.1. Inter-Area Path Computation . . . . . . . . . . . . . . . 16 4.1. Inter-Area Path Computation . . . . . . . . . . . . . . . 16
4.2. Inter-AS Path Computation . . . . . . . . . . . . . . . . 18 4.2. Inter-AS Path Computation . . . . . . . . . . . . . . . . 18
4.2.1. Example 1 . . . . . . . . . . . . . . . . . . . . . . 19 4.2.1. Example 1 . . . . . . . . . . . . . . . . . . . . . . 19
4.2.2. Example 2 . . . . . . . . . . . . . . . . . . . . . . 21 4.2.2. Example 2 . . . . . . . . . . . . . . . . . . . . . . 21
4.3. Boundary Node and Inter-AS-Link . . . . . . . . . . . . . 23 4.3. Boundary Node and Inter-AS-Link . . . . . . . . . . . . . 23
4.4. PCE Serving multiple Domains . . . . . . . . . . . . . . 24 4.4. PCE Serving multiple Domains . . . . . . . . . . . . . . 24
4.5. P2MP . . . . . . . . . . . . . . . . . . . . . . . . . . 24 4.5. P2MP . . . . . . . . . . . . . . . . . . . . . . . . . . 24
4.6. Hierarchical PCE . . . . . . . . . . . . . . . . . . . . 24 4.6. Hierarchical PCE . . . . . . . . . . . . . . . . . . . . 26
5. Other Considerations . . . . . . . . . . . . . . . . . . . . 25 5. Other Considerations . . . . . . . . . . . . . . . . . . . . 26
5.1. Relationship to PCE Sequence . . . . . . . . . . . . . . 25 5.1. Relationship to PCE Sequence . . . . . . . . . . . . . . 26
5.2. Relationship to RSVP-TE . . . . . . . . . . . . . . . . . 25 5.2. Relationship to RSVP-TE . . . . . . . . . . . . . . . . . 26
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 26 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 27
6.1. New Subobjects . . . . . . . . . . . . . . . . . . . . . 26 6.1. New Subobjects . . . . . . . . . . . . . . . . . . . . . 27
7. Security Considerations . . . . . . . . . . . . . . . . . . . 26 7. Security Considerations . . . . . . . . . . . . . . . . . . . 27
8. Manageability Considerations . . . . . . . . . . . . . . . . 26 8. Manageability Considerations . . . . . . . . . . . . . . . . 28
8.1. Control of Function and Policy . . . . . . . . . . . . . 26 8.1. Control of Function and Policy . . . . . . . . . . . . . 28
8.2. Information and Data Models . . . . . . . . . . . . . . . 27 8.2. Information and Data Models . . . . . . . . . . . . . . . 28
8.3. Liveness Detection and Monitoring . . . . . . . . . . . . 27 8.3. Liveness Detection and Monitoring . . . . . . . . . . . . 29
8.4. Verify Correct Operations . . . . . . . . . . . . . . . . 27 8.4. Verify Correct Operations . . . . . . . . . . . . . . . . 29
8.5. Requirements On Other Protocols . . . . . . . . . . . . . 27 8.5. Requirements On Other Protocols . . . . . . . . . . . . . 29
8.6. Impact On Network Operations . . . . . . . . . . . . . . 27 8.6. Impact On Network Operations . . . . . . . . . . . . . . 29
9. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 28 9. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 29
10. References . . . . . . . . . . . . . . . . . . . . . . . . . 28 10. References . . . . . . . . . . . . . . . . . . . . . . . . . 30
10.1. Normative References . . . . . . . . . . . . . . . . . . 28 10.1. Normative References . . . . . . . . . . . . . . . . . . 30
10.2. Informative References . . . . . . . . . . . . . . . . . 29 10.2. Informative References . . . . . . . . . . . . . . . . . 31
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 30 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 33
1. Introduction 1. Introduction
A Path Computation Element (PCE) may be used to compute end-to-end A Path Computation Element (PCE) may be used to compute end-to-end
paths across multi-domain environments using a per-domain path paths across multi-domain environments using a per-domain path
computation technique [RFC5152]. The backward recursive path computation technique [RFC5152]. The backward recursive path
computation (BRPC) mechanism [RFC5441] also defines a PCE-based path computation (BRPC) mechanism [RFC5441] also defines a PCE-based path
computation procedure to compute inter-domain constrained path for computation procedure to compute inter-domain constrained path for
(G)MPLS TE LSPs. However, both per-domain and BRPC techniques assume (G)MPLS TE LSPs. However, both per-domain and BRPC techniques assume
that the sequence of domains to be crossed from source to destination that the sequence of domains to be crossed from source to destination
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[DOMAIN-SUBOBJ]. [DOMAIN-SUBOBJ].
1.1. Scope 1.1. Scope
The procedures described in this document are experimental. The The procedures described in this document are experimental. The
experiment is intended to enable research for the usage of Domain- experiment is intended to enable research for the usage of Domain-
Sequence at the PCEs for inter-domain paths. For this purpose this Sequence at the PCEs for inter-domain paths. For this purpose this
document specifies new domain subobjects as well as how they document specifies new domain subobjects as well as how they
incorporate with existing subobjects to represent a Domain-Sequence. incorporate with existing subobjects to represent a Domain-Sequence.
The experiment will end two years after the RFC is published. At
that point, the RFC authors will attempt to determine how widely this
has been implemented and deployed.
This document does not change the procedures for handling existing This document does not change the procedures for handling existing
subobjects in PCEP. subobjects in PCEP.
The new subobjects introduced by this document will not be understood The new subobjects introduced by this document will not be understood
by a legacy implementation. If one of the subobjects is received in by legacy implementations. If a legacy implementation receives one
a PCEP object that does not understand it, it will behave as of the subobjects that it does not understand in a PCEP object, the
described in Section 3.4.3. Therefore, it is assumed that this legacy implementation will behave as described in Section 3.4.3.
experiment will be conducted only when both the PCE and the PCC form Therefore, it is assumed that this experiment will be conducted only
part of the experiment. It is possible that a PCC or PCE can operate when both the PCE and the PCC form part of the experiment. It is
with peers some of which form part of the experiment and some that do possible that a PCC or PCE can operate with peers some of which form
not. In this case, since no capabilities exchange is used to part of the experiment and some that do not. In this case, since no
identify which nodes can use these extensions, manual configuration capabilities exchange is used to identify which nodes can use these
should be used to determine which peerings form part of the extensions, manual configuration should be used to determine which
experiment. peerings form part of the experiment.
When the result of implementation and deployment are available, this When the result of implementation and deployment are available, this
document will be updated and refined, and then be moved from document will be updated and refined, and then be moved from
Experimental to Standard Track. Experimental to Standard Track.
1.2. Requirements Language 1.2. Requirements Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in [RFC2119]. document are to be interpreted as described in [RFC2119].
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that has this link. that has this link.
* Otherwise, it assumes that the subobject belongs to the current * Otherwise, it assumes that the subobject belongs to the current
Area. Area.
o In case the current PCE is not responsible for the path o In case the current PCE is not responsible for the path
computation in the current AS or Area, then the PCE selects the computation in the current AS or Area, then the PCE selects the
"next PCE" in the domain-sequence based on the current AS and "next PCE" in the domain-sequence based on the current AS and
Area. Area.
Note that it is advised that, PCC should use AS and Area subobject
while building the domain-sequence in IRO and avoid using other
mechanism to change the "current AS" and "current Area" as described
above.
3.5. Exclude Route Object (XRO) 3.5. Exclude Route Object (XRO)
The Exclude Route Object (XRO) [RFC5521] is an optional object used The Exclude Route Object (XRO) [RFC5521] is an optional object used
to specify exclusion of certain abstract nodes or resources from the to specify exclusion of certain abstract nodes or resources from the
whole path. whole path.
3.5.1. Subobjects 3.5.1. Subobjects
Some subobjects to be used in XRO as defined in [RFC3209], [RFC3477], Some subobjects to be used in XRO as defined in [RFC3209], [RFC3477],
[RFC4874], and [RFC5520], but new subobjects related to Domain- [RFC4874], and [RFC5520], but new subobjects related to Domain-
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All other fields are consistent with the definition in Section 3.4. All other fields are consistent with the definition in Section 3.4.
All the processing rules are as per [RFC5521]. All the processing rules are as per [RFC5521].
Note that, if a PCE receives an XRO in a PCReq message that contains Note that, if a PCE receives an XRO in a PCReq message that contains
subobjects defined in this document, that it does not recognize, it subobjects defined in this document, that it does not recognize, it
will respond according to the rules for a malformed object as per will respond according to the rules for a malformed object as per
[RFC5440]. [RFC5440].
IGP Area subobjects in the XRO are local to the current AS. In case
of multi-AS path computation to exclude an IGP area in a different
AS, IGP Area subobject should be part of Explicit Exclusion Route
Subobject (EXRS) in the IRO to specify the AS in which the IGP area
is to be excluded. Further policy may be applied to prune/ignore
Area subobjects in XRO after "current AS" change during path
computation.
3.6. Explicit Exclusion Route Subobject (EXRS) 3.6. Explicit Exclusion Route Subobject (EXRS)
Explicit Exclusion Route Subobject (EXRS) [RFC5521] is used to EXRS [RFC5521] is used to specify exclusion of certain abstract nodes
specify exclusion of certain abstract nodes between a specific pair between a specific pair of nodes.
of nodes.
The EXRS subobject can carry any of the subobjects defined for The EXRS subobject can carry any of the subobjects defined for
inclusion in the XRO, thus the new subobjects to support 4 byte AS inclusion in the XRO, thus the new subobjects to support 4 byte AS
and IGP (OSPF / ISIS) Area can also be used in the EXRS. The and IGP (OSPF / ISIS) Area can also be used in the EXRS. The
meanings of the fields of the new XRO subobjects are unchanged when meanings of the fields of the new XRO subobjects are unchanged when
the subobjects are included in an EXRS, except that scope of the the subobjects are included in an EXRS, except that scope of the
exclusion is limited to the single hop between the previous and exclusion is limited to the single hop between the previous and
subsequent elements in the IRO. subsequent elements in the IRO.
The EXRS subobject should be interpreted in the context of the The EXRS subobject should be interpreted in the context of the
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| +--+ | | | | | | +--+ | | | | |
| | | +--+ | | | | +--+ |
| | | | | | | |
| Area 1 | | Area 5 | | Area 1 | | Area 5 |
----------------- ------------------ ----------------- ------------------
Figure 1: Inter-Area Path Computation Figure 1: Inter-Area Path Computation
AS Number is 100. AS Number is 100.
This could be represented in the IRO as: If the ingress is in Area 2, egress in Area 4 and transit through
Area 0. Some possible way a PCC can encode the IRO:
+---------+ +---------+ +---------+ +---------+ +---------+ +---------+
|IRO | |Sub | |Sub | |IRO | |Sub | |Sub |
|Object | |Object | |Object | |Object | |Object | |Object |
|Header | |Area 0 | |Area 4 | |Header | |Area 0 | |Area 4 |
| | | | | | | | | | | |
| | | | | | | | | | | |
+---------+ +---------+ +---------+ +---------+ +---------+ +---------+
or or
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\ / / \ / /
A3----------D1---D2---D3---------C3 A3----------D1---D2---D3---------C3
<----------> <---------->
AS D AS D
* All AS have one area (area 0) * All AS have one area (area 0)
Figure 2: Inter-AS Path Computation Figure 2: Inter-AS Path Computation
This could be represented in the IRO as: If the ingress is in AS A, egress in AS C and transit through AS B.
Some possible way a PCC can encode the IRO:
+-------+ +-------+ +-------+ +-------+ +-------+ +-------+
|IRO | |Sub | |Sub | |IRO | |Sub | |Sub |
|Object | |Object | |Object | |Object | |Object | |Object |
|Header | |AS B | |AS C | |Header | |AS B | |AS C |
| | | | | | | | | | | |
+-------+ +-------+ +-------+ +-------+ +-------+ +-------+
or or
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| | +--+ | | | | | +--+ | | |
| | | | | | | | | |
| +------------+ +----------------+ | +------------+ +----------------+
| |
| |
AS 100 | AS 200 AS 100 | AS 200
| |
Figure 3: Inter-AS Path Computation Figure 3: Inter-AS Path Computation
The Domain-Sequence for the LSP (A-B) can be carried in the IRO as For LSP (A-B), where ingress A is in (AS 100, Area 0), egress B in
shown below: (AS 200, Area 4) and transit through (AS 200, Area 0). Some possible
way a PCC can encode the IRO:
+-------+ +-------+ +-------+ +-------+ +-------+ +-------+ +-------+ +-------+
|IRO | |Sub | |Sub | |Sub | |IRO | |Sub | |Sub | |Sub |
|Object | |Object | |Object | |Object | |Object | |Object | |Object | |Object |
|Header | |AS 200 | |Area 0 | |Area 4 | |Header | |AS 200 | |Area 0 | |Area 4 |
| | | | | | | | | | | | | | | |
+-------+ +-------+ +-------+ +-------+ +-------+ +-------+ +-------+ +-------+
or or
+-------+ +-------+ +-------+ +-------+ +-------+ +-------+ +-------+ +-------+ +-------+ +-------+ +-------+ +-------+
|IRO | |Sub | |Sub | |Sub | |Sub | |Sub | |IRO | |Sub | |Sub | |Sub | |Sub | |Sub |
|Object | |Object | |Object | |Object | |Object | |Object | |Object | |Object | |Object | |Object | |Object | |Object |
|Header | |AS 100 | |Area 0 | |AS 200 | |Area 0 | |Area 4 | |Header | |AS 100 | |Area 0 | |AS 200 | |Area 0 | |Area 4 |
| | | | | | | | | | | | | | | | | | | | | | | |
+-------+ +-------+ +-------+ +-------+ +-------+ +-------+ +-------+ +-------+ +-------+ +-------+ +-------+ +-------+
The Domain-Sequence for the LSP (A-C) can be carried in the IRO as For LSP (A-C), where ingress A is in (AS 100, Area 0), egress C in
shown below: (AS 200, Area 5) and transit through (AS 200, Area 0). Some possible
way a PCC can encode the IRO:
+-------+ +-------+ +-------+ +-------+ +-------+ +-------+ +-------+ +-------+
|IRO | |Sub | |Sub | |Sub | |IRO | |Sub | |Sub | |Sub |
|Object | |Object | |Object | |Object | |Object | |Object | |Object | |Object |
|Header | |AS 200 | |Area 0 | |Area 5 | |Header | |AS 200 | |Area 0 | |Area 5 |
| | | | | | | | | | | | | | | |
+-------+ +-------+ +-------+ +-------+ +-------+ +-------+ +-------+ +-------+
or or
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A PCE which can support adjacent domains can internally handle those A PCE which can support adjacent domains can internally handle those
domains in the Domain-Sequence without any impact on the other domains in the Domain-Sequence without any impact on the other
domains in the Domain-Sequence. domains in the Domain-Sequence.
4.5. P2MP 4.5. P2MP
[RFC7334] describes an experimental inter-domain P2MP path [RFC7334] describes an experimental inter-domain P2MP path
computation mechanism where the path domain tree is described as a computation mechanism where the path domain tree is described as a
series of Domain-Sequences, an example is shown in the below figure: series of Domain-Sequences, an example is shown in the below figure:
D1-D3-D6, D1-D3-D5 and D1-D2-D4. +----------------+
D1 | |Domain D1
/ \ | R |
D2 D3 | |
/ / \ | A |
D4 D5 D6 | |
+-B------------C-+
/ \
/ \
/ \
Domain D2 / \ Domain D3
+-------------D--+ +-----E----------+
| | | |
| F | | |
| G | | H |
| | | |
| | | |
+-I--------------+ +-J------------K-+
/\ / \
/ \ / \
/ \ / \
/ \ / \
/ \ / \
/ \ / \
/ Domain D4 \ Domain D5 / Domain D6 \
+-L-------------W+ +------P---------+ +-----------T----+
| | | | | |
| | | Q | | U |
| M O | | S | | |
| | | | | V |
| N | | R | | |
+----------------+ +----------------+ +----------------+
The domain tree can be represented as a series of domain-sequence -
o Domian D1, Domian D3, Domian D6
o Domian D1, Domian D3, Domian D5
o Domian D1, Domian D2, Domian D4
The domain sequence handling described in this document could be The domain sequence handling described in this document could be
applied to P2MP path domain tree. applied to P2MP path domain tree.
4.6. Hierarchical PCE 4.6. Hierarchical PCE
In case of H-PCE [RFC6805], the parent PCE can be requested to In case of H-PCE [RFC6805], the parent PCE can be requested to
determine the Domain-Sequence and return it in the path computation determine the Domain-Sequence and return it in the path computation
reply, using the ERO. . For the example in section 4.6 of [RFC6805], reply, using the ERO. . For the example in section 4.6 of [RFC6805],
the Domain-Sequence can possibly appear as: the Domain-Sequence can possibly appear as:
skipping to change at page 26, line 10 skipping to change at page 27, line 15
(XRO) or Explicit Exclusion Route Subobject (EXRS) in RSVP-TE. (XRO) or Explicit Exclusion Route Subobject (EXRS) in RSVP-TE.
In any case subobject type defined in RSVP-TE are identical to the In any case subobject type defined in RSVP-TE are identical to the
subobject type defined in the related documents in PCEP. subobject type defined in the related documents in PCEP.
6. IANA Considerations 6. IANA Considerations
6.1. New Subobjects 6.1. New Subobjects
IANA maintains the "Path Computation Element Protocol (PCEP) Numbers" IANA maintains the "Path Computation Element Protocol (PCEP) Numbers"
at http://www.iana.org/assignments/pcep/pcep.xhtml. Within this at <http://www.iana.org/assignments/pcep>. Within this registry IANA
registry IANA maintains two sub-registries: maintains two sub-registries:
o "IRO Subobjects": http://www.iana.org/assignments/pcep/ o "IRO Subobjects": <http://www.iana.org/assignments/pcep#iro-
pcep.xhtml#iro-subobject subobject>
o "XRO Subobjects": http://www.iana.org/assignments/pcep/ o "XRO Subobjects": <http://www.iana.org/assignments/pcep#xro-
pcep.xhtml#xro-subobject subobject>
Upon approval of this document, IANA is requested to make identical Upon approval of this document, IANA is requested to make identical
additions to these registries as follows: additions to these registries as follows:
Subobject Type Reference Subobject Type Reference
TBD1 4 byte AS number [This I.D.][DOMAIN-SUBOBJ] TBD1 4 byte AS number [This I.D.][DOMAIN-SUBOBJ]
TBD2 OSPF Area ID [This I.D.][DOMAIN-SUBOBJ] TBD2 OSPF Area ID [This I.D.][DOMAIN-SUBOBJ]
TBD3 IS-IS Area ID [This I.D.][DOMAIN-SUBOBJ] TBD3 IS-IS Area ID [This I.D.][DOMAIN-SUBOBJ]
Further upon approval of this document, IANA is requested to add a
reference to this document to the new RSVP numbers that are
registered by [DOMAIN-SUBOBJ].
7. Security Considerations 7. Security Considerations
This document specifies a standard representation of Domain-Sequence The protocol extensions defined in this document do not substantially
and new subobjects, which could be used in inter-domain PCE scenarios change the nature of PCEP. Therefore, the security considerations
as explained in other RFC and drafts. The new subobjects and Domain- set out in [RFC5440] apply unchanged. Note that further security
Sequence mechanisms defined in this document allow finer and more considerations for the use of PCEP over TCP are presented in
specific control of the path computed by a cooperating PCE(s). Such [RFC6952].
control increases the risk if a PCEP message is intercepted,
modified, or spoofed because it allows the attacker to exert control This document specifies a representation of Domain-Sequence and new
over the path that the PCE will compute or to make the path subobjects, which could be used in inter-domain PCE scenarios as
computation impossible. Therefore, the security techniques described explained in [RFC5152], [RFC5441], [RFC6805], [RFC7334] etc. The
in [RFC5440] are considered more important. security considerations set out in each of these mechanisms remain
unchanged by the new subobjects and Domain-Sequence representation in
this document.
But the new subobjects do allow finer and more specific control of
the path computed by a cooperating PCE(s). Such control increases
the risk if a PCEP message is intercepted, modified, or spoofed
because it allows the attacker to exert control over the path that
the PCE will compute or to make the path computation impossible.
Consequently, it is important that implementations conform to the
relevant security requirements of [RFC5440]. These mechanisms
include:
o Securing the PCEP session messages using TCP security techniques
(Section 10.2 of [RFC5440]). PCEP implementations SHOULD also
consider the additional security provided by the TCP
Authentication Option (TCP-AO) [RFC5925] or [PCEPS].
o Authenticating the PCEP messages to ensure the message is intact
and sent from an authorized node (Section 10.3 of [RFC5440]).
o PCEP operates over TCP, so it is also important to secure the PCE
and PCC against TCP denial-of-service attacks. Section 10.7.1 of
[RFC5440] outlines a number of mechanisms for minimizing the risk
of TCP-based denial-of-service attacks against PCEs and PCCs.
o In inter-AS scenarios, attacks may be particularly significant
with commercial as well as service-level implications.
Note, however, that the Domain-Sequence mechanisms also provide the Note, however, that the Domain-Sequence mechanisms also provide the
operator with the ability to route around vulnerable parts of the operator with the ability to route around vulnerable parts of the
network and may be used to increase overall network security. network and may be used to increase overall network security.
8. Manageability Considerations 8. Manageability Considerations
8.1. Control of Function and Policy 8.1. Control of Function and Policy
The exact behaviour with regards to desired inclusion and exclusion The exact behaviour with regards to desired inclusion and exclusion
of domains MUST be available for examination by an operator and MAY of domains MUST be available for examination by an operator and MAY
be configurable. Manual configurations is needed to identify which be configurable. Manual configurations is needed to identify which
PCEP peers understand the new domain subobjects defined in this PCEP peers understand the new domain subobjects defined in this
document. document.
8.2. Information and Data Models 8.2. Information and Data Models
A MIB module for management of the PCEP is being specified in a A MIB module for management of the PCEP is being specified in a
separate document [RFC7420]. This document does not imply any new separate document [RFC7420]. This document does not imply any new
extention to the current MIB module. extension to the current MIB module.
8.3. Liveness Detection and Monitoring 8.3. Liveness Detection and Monitoring
Mechanisms defined in this document do not imply any new liveness Mechanisms defined in this document do not imply any new liveness
detection and monitoring requirements in addition to those already detection and monitoring requirements in addition to those already
listed in [RFC5440]. listed in [RFC5440].
8.4. Verify Correct Operations 8.4. Verify Correct Operations
Mechanisms defined in this document do not imply any new operation Mechanisms defined in this document do not imply any new operation
skipping to change at page 28, line 15 skipping to change at page 30, line 7
9. Acknowledgments 9. Acknowledgments
Authors would like to especially thank Adrian Farrel for his detailed Authors would like to especially thank Adrian Farrel for his detailed
reviews as well as providing text to be included in the document. reviews as well as providing text to be included in the document.
Further, we would like to thank Pradeep Shastry, Suresh Babu, Quintin Further, we would like to thank Pradeep Shastry, Suresh Babu, Quintin
Zhao, Fatai Zhang, Daniel King, Oscar Gonzalez, Chen Huaimo, Zhao, Fatai Zhang, Daniel King, Oscar Gonzalez, Chen Huaimo,
Venugopal Reddy, Reeja Paul, Sandeep Boina, Avantika Sergio Belotti Venugopal Reddy, Reeja Paul, Sandeep Boina, Avantika Sergio Belotti
and Jonathan Hardwick for their useful comments and suggestions. and Jonathan Hardwick for their useful comments and suggestions.
Thanks to Jonathan Hardwick for shepherding this document.
Thanks to Joel Halpern for Gen-ART Review.
Thanks to Klaas Wierenga for SecDir Review.
Thanks to Spencer Dawkins and Barry Leiba for comments during the
IESG Review.
10. References 10. References
10.1. Normative References 10.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997, DOI 10.17487/RFC2119, March 1997,
<http://www.rfc-editor.org/info/rfc2119>. <http://www.rfc-editor.org/info/rfc2119>.
[RFC3209] Awduche, D., Berger, L., Gan, D., Li, T., Srinivasan, V., [RFC3209] Awduche, D., Berger, L., Gan, D., Li, T., Srinivasan, V.,
skipping to change at page 29, line 31 skipping to change at page 31, line 31
[IRO-UPDATE] [IRO-UPDATE]
Dhody, D., "Update to Include Route Object (IRO) Dhody, D., "Update to Include Route Object (IRO)
specification in Path Computation Element communication specification in Path Computation Element communication
Protocol (PCEP. (draft-ietf-pce-iro-update-02)", May 2015. Protocol (PCEP. (draft-ietf-pce-iro-update-02)", May 2015.
[DOMAIN-SUBOBJ] [DOMAIN-SUBOBJ]
Dhody, D., Palle, U., Kondreddy, V., and R. Casellas, Dhody, D., Palle, U., Kondreddy, V., and R. Casellas,
"Domain Subobjects for Resource ReserVation Protocol - "Domain Subobjects for Resource ReserVation Protocol -
Traffic Engineering (RSVP-TE). (draft-ietf-teas-rsvp-te- Traffic Engineering (RSVP-TE). (draft-ietf-teas-rsvp-te-
domain-subobjects-02)", July 2015. domain-subobjects-04)", November 2015.
10.2. Informative References 10.2. Informative References
[RFC4655] Farrel, A., Vasseur, J., and J. Ash, "A Path Computation [RFC4655] Farrel, A., Vasseur, J., and J. Ash, "A Path Computation
Element (PCE)-Based Architecture", RFC 4655, Element (PCE)-Based Architecture", RFC 4655,
DOI 10.17487/RFC4655, August 2006, DOI 10.17487/RFC4655, August 2006,
<http://www.rfc-editor.org/info/rfc4655>. <http://www.rfc-editor.org/info/rfc4655>.
[RFC4726] Farrel, A., Vasseur, J., and A. Ayyangar, "A Framework for [RFC4726] Farrel, A., Vasseur, J., and A. Ayyangar, "A Framework for
Inter-Domain Multiprotocol Label Switching Traffic Inter-Domain Multiprotocol Label Switching Traffic
skipping to change at page 30, line 22 skipping to change at page 32, line 22
"Preserving Topology Confidentiality in Inter-Domain Path "Preserving Topology Confidentiality in Inter-Domain Path
Computation Using a Path-Key-Based Mechanism", RFC 5520, Computation Using a Path-Key-Based Mechanism", RFC 5520,
DOI 10.17487/RFC5520, April 2009, DOI 10.17487/RFC5520, April 2009,
<http://www.rfc-editor.org/info/rfc5520>. <http://www.rfc-editor.org/info/rfc5520>.
[RFC5886] Vasseur, JP., Ed., Le Roux, JL., and Y. Ikejiri, "A Set of [RFC5886] Vasseur, JP., Ed., Le Roux, JL., and Y. Ikejiri, "A Set of
Monitoring Tools for Path Computation Element (PCE)-Based Monitoring Tools for Path Computation Element (PCE)-Based
Architecture", RFC 5886, DOI 10.17487/RFC5886, June 2010, Architecture", RFC 5886, DOI 10.17487/RFC5886, June 2010,
<http://www.rfc-editor.org/info/rfc5886>. <http://www.rfc-editor.org/info/rfc5886>.
[RFC5925] Touch, J., Mankin, A., and R. Bonica, "The TCP
Authentication Option", RFC 5925, DOI 10.17487/RFC5925,
June 2010, <http://www.rfc-editor.org/info/rfc5925>.
[RFC6793] Vohra, Q. and E. Chen, "BGP Support for Four-Octet [RFC6793] Vohra, Q. and E. Chen, "BGP Support for Four-Octet
Autonomous System (AS) Number Space", RFC 6793, Autonomous System (AS) Number Space", RFC 6793,
DOI 10.17487/RFC6793, December 2012, DOI 10.17487/RFC6793, December 2012,
<http://www.rfc-editor.org/info/rfc6793>. <http://www.rfc-editor.org/info/rfc6793>.
[RFC6952] Jethanandani, M., Patel, K., and L. Zheng, "Analysis of
BGP, LDP, PCEP, and MSDP Issues According to the Keying
and Authentication for Routing Protocols (KARP) Design
Guide", RFC 6952, DOI 10.17487/RFC6952, May 2013,
<http://www.rfc-editor.org/info/rfc6952>.
[RFC7334] Zhao, Q., Dhody, D., King, D., Ali, Z., and R. Casellas, [RFC7334] Zhao, Q., Dhody, D., King, D., Ali, Z., and R. Casellas,
"PCE-Based Computation Procedure to Compute Shortest "PCE-Based Computation Procedure to Compute Shortest
Constrained Point-to-Multipoint (P2MP) Inter-Domain Constrained Point-to-Multipoint (P2MP) Inter-Domain
Traffic Engineering Label Switched Paths", RFC 7334, Traffic Engineering Label Switched Paths", RFC 7334,
DOI 10.17487/RFC7334, August 2014, DOI 10.17487/RFC7334, August 2014,
<http://www.rfc-editor.org/info/rfc7334>. <http://www.rfc-editor.org/info/rfc7334>.
[RFC7420] Koushik, A., Stephan, E., Zhao, Q., King, D., and J. [RFC7420] Koushik, A., Stephan, E., Zhao, Q., King, D., and J.
Hardwick, "Path Computation Element Communication Protocol Hardwick, "Path Computation Element Communication Protocol
(PCEP) Management Information Base (MIB) Module", (PCEP) Management Information Base (MIB) Module",
RFC 7420, DOI 10.17487/RFC7420, December 2014, RFC 7420, DOI 10.17487/RFC7420, December 2014,
<http://www.rfc-editor.org/info/rfc7420>. <http://www.rfc-editor.org/info/rfc7420>.
[PCEPS] Lopez, D., Dios, O., Wu, W., and D. Dhody, "Secure
Transport for PCEP", draft-ietf-pce-pceps-05 (work in
progress), November 2015.
Authors' Addresses Authors' Addresses
Dhruv Dhody Dhruv Dhody
Huawei Technologies Huawei Technologies
Divyashree Techno Park, Whitefield Divyashree Techno Park, Whitefield
Bangalore, Karnataka 560037 Bangalore, Karnataka 560037
India India
EMail: dhruv.ietf@gmail.com EMail: dhruv.ietf@gmail.com
Udayasree Palle Udayasree Palle
Huawei Technologies Huawei Technologies
Divyashree Techno Park, Whitefield Divyashree Techno Park, Whitefield
Bangalore, Karnataka 560037 Bangalore, Karnataka 560037
India India
EMail: udayasree.palle@huawei.com EMail: udayasree.palle@huawei.com
Ramon Casellas Ramon Casellas
CTTC CTTC
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