Network Working Group S. Sivabalan
Internet-Draft C. Filsfils
Intended status: Standards Track J. Medved
Expires: December 19, 2013 Cisco Systems, Inc.
E. Crabbe
Google, Inc.
R. Raszuk
NTT I3
June 17, 2013
PCE-Initiated Traffic Engineering Path Setup in Segment Routed Networks
draft-sivabalan-pce-segment-routing-00.txt
Abstract
Segment Routing (SR) enables any head-end node to select any path
without relying on a hop-by-hop signaling technique (e.g., LDP or
RSVP-TE). It depends only on "segments" that are advertised by Link-
State Interior Gateway Protocols (IGPs). A Segment Routed Path can
be derived from a variety of mechanisms, including an IGP Shortest
Path Tree (SPT), explicit configuration, or a stateful Path
Computation Element (PCE). This document specifies extensions to the
Path Computation Element Protocol (PCEP) that allow a stateful PCE to
signal and instantiate Traffic Engineering paths in SR networks.
Requirements Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in [RFC2119].
Status of this Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet-
Drafts is at http://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
This Internet-Draft will expire on December 19, 2013.
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Copyright Notice
Copyright (c) 2013 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
(http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with respect
to this document. Code Components extracted from this document must
include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4
3. Overview of PCEP Operation in SR Networks . . . . . . . . . . 4
4. SR Capability Negotiation . . . . . . . . . . . . . . . . . . 5
4.1. Negotiating SR Capability . . . . . . . . . . . . . . . . 6
5. SR-ERO objects . . . . . . . . . . . . . . . . . . . . . . . . 6
5.1. The SR-ERO Subobject . . . . . . . . . . . . . . . . . . . 6
5.2. NAI Associated with SID . . . . . . . . . . . . . . . . . 8
5.3. SR-ERO Processing . . . . . . . . . . . . . . . . . . . . 10
6. The SR-RRO Object . . . . . . . . . . . . . . . . . . . . . . 10
7. SR Specific PCEP Descriptors . . . . . . . . . . . . . . . . . 11
7.1. PCEP Descriptor for PCCreate Message . . . . . . . . . . . 11
7.2. PCEP Descriptor for PCRpt Message . . . . . . . . . . . . 11
7.3. PCEP Descriptor for PCUpd Message . . . . . . . . . . . . 12
8. Backward Compatibility . . . . . . . . . . . . . . . . . . . . 12
9. Management Considerations . . . . . . . . . . . . . . . . . . 12
9.1. Policy . . . . . . . . . . . . . . . . . . . . . . . . . . 12
9.2. The PCEP Data Model . . . . . . . . . . . . . . . . . . . 13
10. Security Considerations . . . . . . . . . . . . . . . . . . . 13
11. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 13
12. Acknowledgement . . . . . . . . . . . . . . . . . . . . . . . 13
13. References . . . . . . . . . . . . . . . . . . . . . . . . . . 13
13.1. Normative References . . . . . . . . . . . . . . . . . . . 13
13.2. Informative References . . . . . . . . . . . . . . . . . . 15
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 15
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1. Introduction
In SR networks, a chosen without relying on hop-by-hop signaling
protocols such as LDP or RSVP-TE. Each path is specified as a set of
"segments" advertised by link-state routing protocols (IS-IS or
OSPF). [SR-ARCH] provides an introduction to SR technology. The
corresponding IS-IS extension and OSPF extension are specified
repectively in [SR-ISIS] and a document to be published soon. Two
types of segments have been defined; nodal and adjacency segments. A
nodal segment represents a path to a node, whereas an adjacency
segment represents a specific adjacency to a node. A Segment
Identifier (SID) is a 32-bit value and can be applied to both IP and
MPLS data planes. In the case of the MPLS data plane, an SR path
corresponds to an MPLS Label Switching Path (LSP)
A Segment Routed path (SR path) can be derived from an IGP Shortest
Path Tree (SPT). Segment Routed Traffic Engineering paths (SR-TE
paths) may not follow IGP SPT. Such paths may be chosen by a
suitable network planning tool and provisioned on the source node of
the SR-TE path.
[RFC5440] describes Path Computation Element Protocol (PCEP) for
communication between a Path Computation Client (PCC) and a Path
Control Element (PCE) or between one a pair of PCEs. A PCE computes
paths for MPLS Traffic Engineering LSPs (MPLS-TE LSPs) based on
various constraints and optimization criteria.
[I-D.ietf-pce-stateful-pce] specifies extensions to PCEP that allow a
stateful PCE to compute and recommend network paths in compliance
with [RFC4657]. Stateful PCEP extensions provide synchronization of
LSP state between a PCC and a PCE or between a pair of PCEs,
delegation of LSP control, reporting of LSP state from a PCC to a
PCE, controlling the setup and path routing of an LSP from a PCE to a
PCC. Stateful PCEP extensions are intended for an operational model
in which LSPs are configured on the PCC, and control over them is
delegated to the PCE. [I-D.crabbe-pce-stateful-pce-mpls-te] builds
on [I-D.ietf-pce-stateful-pce] to specify objects and TLVs for
MPLS-TE LSPs. Moreover, a mechanism to dynamically instantiate LSPs
on a PCC based on the requests from a stateful PCE or a controller
using stateful PCE is specified in
[I-D.crabbe-pce-pce-initiated-lsp]. Such mechanism is useful in
Software Driven Networks (SDN) applications, such as demand
engineering, or bandwidth calendaring.
It is possible to use a stateful PCE for computing one or more SR-TE
paths taking into account various constraints and objective
functions. Once a path is chosen, the stateful PCE can instantiate
an SR-TE path on the PCC using PCEP extensions specified in
[I-D.crabbe-pce-pce-initiated-lsp] along with the SR specific PCEP
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extensions provided in this document.
2. Terminology
The following terminologies are used in this document:
ERO: Explicit Route Object.
IGP: Interior Gateway Protocol.
IS-IS: Intermediate System to Intermediate System.
LSR: Label Switching Router.
NAI: Node or Adjacency Identifier.
OSPF: Open Shortest Path First.
PCC: Path Computation Client.
PCE: Path Computation Element
PCEP: Path Computation Element Protocol.
RRO: Record Route Object.
SR: Segment Routing.
SR-ERO: Segment Routed Explicit Route Object.
SR Path: Segment Routed Path.
SR-RRO: Segment Routed Record Route Object.
SR-TE Path: Segment Routed Traffic Engineering Path.
3. Overview of PCEP Operation in SR Networks
In SR networks, an ingress node of an SR path appends all outgoing
packets with an SR header consisting of a list of Segment IDs (SIDs).
The header has all necessary information to guide the packets from
the ingress node to the egress node of the path, and hence there is
no need for any signaling protocol. A SID can represent a nodal
segment representing a path to a node or adjacency segment
representing path over a specific adjacency.
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In a PCEP session, path information is carried in the Explicit Route
Object (ERO), which consists of a sequence of subobjects. Various
types of ERO subobjects have been specified in [RFC3209], [RFC3473],
and [RFC3477]. In SR networks, a PCE needs to specify ERO containing
SIDs, and a PCC should be capable of processing such ERO. An ERO
containing SIDs can be included in the PCEP Create message (PCCreate)
defined in [I-D.crabbe-pce-pce-initiated-lsp], as well as in the PCEP
Update (PCUpd) and PCEP Report (PCRpt) messages defined in
[I-D.ietf-pce-stateful-pce].
When a PCEP session between a PCC and a PCE is established, both PCEP
Speakers exchange information to indicate their ability to support
SR-specific functionality. A PCEP session can carry EROs of
different types. However, an ERO carrying SIDs MUST NOT include any
other form of EROs, i.e., all subobjects within an ERO MUST represent
SID. Furthermore, if an SR path is established using SR-ERO,
subsequent PCEP Update and Report messages for that path MUST NOT
contain other ERO types. This document specifies new error codes to
handle these errors. Should the need to change the ERO type arise,
the SR path must be deleted and re-created using a new ERO type.
A PCC can include an RRO object in a PCRpt message. In SR networks,
a PCC MAY learn the SR actual path actually taken by data packets and
report that path to a PCE. For this purpose, we introduce a new RRO
subobject type. However, methods used by a PCC to learn SR-TE paths
are outside the scope of this document.
In summary, this document specifies a new PCEP capability, a new ERO
subobject, a new RRO subobject, and new PCEP error codes.
4. SR Capability Negotiation
The format of the STATEFUL-PCE-CAPABILITY TLV 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= TBD | Length=4 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Flags |R|I|S|U|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 1: STATEFUL-PCE-CAPABILITY TLV format
The type of the TLV is to be defined in [I-D.ietf-pce-stateful-pce].
The TLV length is 4 octets.
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The value comprises a single field - Flags (32 bits). The U and S
flags are defined in [I-D.ietf-pce-stateful-pce]. The I flag is
defined in [I-D.crabbe-pce-pce-initiated-lsp].
A new flag - the "R bit" - is used to negotiate the SR capability
between a PCE and a PCC.
4.1. Negotiating SR Capability
By setting the R-bit to 1, a PCEP Speaker indicates that it is SR-
capable, i.e., it is able to perform SR related PCEP functions
specified in this document. An SR-capable PCEP Speaker must be able
to handle EROs containing SIDs (referred to as "SR-EROs" in this
document). A PCEP Speaker MAY originate SR-ERO only if both PCEP
Speakers in a PCEP session are SR-capable. A pair of SR-capable PCEP
Speakers can exchange SR-EROs in PCCreate and PCUpd messages.
Similarly, an SR-capable PCEP Speaker must be able to handle RROs
containing SIDs (referred to as "SR-RRO" in this document). A pair
of PCEP Speakers can exchange SR-RROs in PCRpt message.
5. SR-ERO objects
An SR-TE path consists of one or more SID(s) where each SID is
associated with the identifier that represents the node or adjacency
corresponding to the SID. This identifier is referred to as the
'Node or Adjacency Identifie'r (NAI). As described later, a NAI can
be represented in various formats (e.g., IPv4 address, IPv6 address,
etc). Furthermore, a NAI is used only for troubleshooting purposes,
and MUST not be used to replace or modify any fields in a data packet
header. An SR-ERO object consists of one or more ERO subobjects
described in the following section.
5.1. The SR-ERO Subobject
An SR-ERO subobject consists of a 32-bit header followed by the SID
and the NAI associated with the SID. The SID is a 32-bit number.
The size of the NAI depends on its respective type, as described in
the following sections.
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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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|L| Type | Length | ST | Flags |F|S|C|M|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| SID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
// NAI (variable) //
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 2: SR-ERO Subobject format
The fields in the ERO Subobject are as follows:
The 'L' Flag indicates whether the subobject represents a loose-hop
in the explicit route [RFC3209]. If this flag is unset, a PCC
MUST not overwrite the SID value present in the SR-ERO subobject.
Otherwise, a PCC MAY expand or replace one or more SID value(s) in
the received SR-ERO based on its local policy.
Type is the type of the SR-ERO Subobject. This document defines the
SR-ERO Subobject type. A new code point will be requested for the
SR-ERO Subobject from IANA.
Length contains the total length of the subobject in octets,
including the L, Type and Length fields. Length MUST be at least
4, and MUST be a multiple of 4.
SID Type (ST) indicates the type of information associated with the
SID contained in the object body. The SID-Type values are
described later in this document.
Flags is used to carry any additional information pertaining to SID.
Currently, the following flag bits are defined:
* M: When this bit is set, the SID value represents an MPLS label
stack entry as specified in [RFC5462] where only the label
value is specified by the PCE. Other fields (TC, S, and TTL)
fields MUST be considered invalid, and PCC MUST set these
fields according to its local policy and MPLS forwarding rules.
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* C: When this bit as well as the M bit are set, then the SID
value represents an MPLS label stack entry as specified in
[RFC5462], where all the entry's fields (Label, TC, S, and TTL)
are specified by the PCE. However, a PCC MAY choose to
override TC, S, and TTL values according its local policy and
MPLS forwarding rules.
* S: When this bit is set, the SID value in the subobject body is
null. In this case, the PCC is responsible for choosing the
SID value, e.g., by looking up its Traffic Engineering Database
(TED) using node/adjacency identifier in the subobject body.
* F: When this bit is set, the NAI value in the subobject body is
null.
SID is the Segment Identifier.
NAI contains the NAI associated with the SID. Depending on the
value of ST, the NAI can have different format as described in the
following section.
5.2. NAI Associated with SID
This document defines the following NAIs:
'IPv4 Node ID' is specified as an IPv4 address. In this case, ST
and Length are 1 and 12 respectively.
'IPv6 Node ID' is specified as an IPv6 address. In this case, ST
and Length are 2 and 20 respectively.
'IPv4 Adjacency' is specified as a pair of IPv4 addresses. In this
case, ST and Length are 3 and 16 repectively, and the format of
the NAI is shown in the following figure:
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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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Local IPv4 address |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Remote IPv4 address |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 3: NAI for IPv4 Adjacency
'IPv6 Adjacency' is specified as a pair of IPv6 addresses. In this
case, ST and Length are 4 and 34 respectively, and the format of
the NAI 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
// Local IPv6 address (16 bytes) //
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
// Remote IPv6 address (16 bytes) //
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 4: NAI for IPv6 adjacency
'Unnumbered Adjacency with IPv4 NodeIDs' is specified as a pair of
Node ID / Interface ID tuples. In this case, ST and Length are 5
and 24 respectively, and the format of the NAI 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Local Node-ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Local Interface ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Remote Node-ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Remote Interface ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 5: NAI for Unnumbered adjacency with IPv4 Node IDs
We are yet to decide if another SID subobject is required for
unnumbered adjacency with 128 bit node ID.
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5.3. SR-ERO Processing
A PCEP Speaker that does not recognize the new ERO subobject in the
PCCreate, PCUpd or PCRpt message MUST reject the entire PCEP message
and MUST send a PCE error message with Error-Type="Unknown Object" or
"Not supported object", defined in [RFC5440].
When the SID represents an MPLS label (i.e. the M bit is set), its
value (20 most significant bits) MUST be larger than 15, unless it is
special purpose label, such as an Entropy Label Indicator (ELI) or an
Entropy Label (EL). If a PCEP Speaker receives a label ERO subobject
with an invalid value, it MUST send the PCE error message with Error-
Type = "Reception of an invalid object" and Error-Value = "Bad label
value". If both M and C bits of an ERO subobject are set, and if a
PCEP Speaker finds erroneous setting in one or more of TC, S, and TTL
fields, it MUST send a PCE error with Error-Type = "Reception of an
invalid object" and Error-Value = "Bad label format".
If a PCC receives a stack of SR-ERO subobjects, and the number of
stack exceeds the maximum number of SIDs that the PCC can impose on
the packet, it MAY send a PCE error with Error-Type = "Reception of
an invalid object" and Error-Value = "Unsupported number of Segment
ERO subobjects".
6. The SR-RRO Object
An SR-RRO objects consists of one or more subobject(s), each carrying
a SID and the associated NAI. The format of the SR-RRO subobject is
the same as the ERO subobject, except for L-flag which does not
exists in the SR-RRO Subobject. Also, there are no flags defined for
the SR-RRO 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | ST | Flags |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| SID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
// NAI (variable) //
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 6: SR-RRO Subobject format
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7. SR Specific PCEP Descriptors
As defined in [RFC5440], a PCEP message consists of a common header
followed by a variable length body made up of mandatory and/or
optional objects. [I-D.ietf-pce-stateful-pce] and
[I-D.crabbe-pce-stateful-pce-mpls-te] respectively describe the
stateful PCEP descriptors for general state control and MPLS-TE
specific state control. Finally, [I-D.crabbe-pce-pce-initiated-lsp]
specifies the PCEP descriptors for PCE-based LSP instantiation. This
document specifies the SR specific PCEP descriptors.
7.1. PCEP Descriptor for PCCreate Message
The format of the PCCreate message is as follows:
<PCCreate Message> ::= <Common Header>
<sr-path-instantiation-list>
Where:
<sr-path-instantiation-list> ::=
<sr-path-instantiation-request>[<sr-path-instantiation-list>]
<sr-path-instantiation-request> ::= <LSP>
<SID-ERO> <----- New subobject
The LSP object in the Common Header MUST include the SYMBOLIC-PATH-
NAME TLV.
7.2. PCEP Descriptor for PCRpt Message
The format of the PCRpt message is as follows:
<PCRpt Message> ::= <Common Header>
<state-report-list>
Where:
<state-report-list> ::= <state-report>[<state-report-list>]
<state-report> ::= <LSP>
<SID-RRO> <------- New RRO subobject
[<prog-sr-path-list>]
Where:
<prog-sr-path-list>::=<prog-sr-path>[<prog-sr-path-list>]
For SR-TE paths, the path descriptor is defined as follows:
<prog-sr-path>::=<ERO> <----- New ERO subobject
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In the PCRpt message, only the LSP object is considered mandatory.
All other objects are optional, and may be included for synchronizing
SR-TE path when PCEP session is re-established.
7.3. PCEP Descriptor for PCUpd Message
The format of a PCUpd message is as follows:
<PCUpd Message> ::= <Common Header>
<update-request-list>
Where:
<update-request-list> ::=
<update-request>[<update-request-list>]
<update-request> ::= <LSP>
[<sr-path-list>]
Where:
<sr-path-list>::=<sr-path>[<sr-path-list>]
For SR-TE paths, the path descriptor is defined as follows:
<sr-path>::=<SID-ERO> <----- New ERO subobject
In the PCUpd message, only the LSP object is considered mandatory.
All other objects are optional, and may be included for synchronizing
SR-TE paths when PCEP session is re-established.
8. Backward Compatibility
An LSR that does not support the SR PCEP capability negotiation
cannot recognize the SR-ERO subobjects. As such, it shall send a
PCEP error with Error-Type = 4 (Not supported object) and Error-Value
= 2 (Not supported object Type) as per [RFC5440].
9. Management Considerations
9.1. Policy
PCEP implementation:
o Can enable SR-PCEP capability either by default or via explicit
configuration.
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o May generate PCEP error due to unsupported number of SR-ERO
subobjects either by default or via explicit configuration.
9.2. The PCEP Data Model
A PCEP MIB module is defined in [I-D.ietf-pce-pcep-mib] needs be
extended to cover additional functionality provided by [RFC5440] and
[I-D.crabbe-pce-pce-initiated-lsp]. Such extension will cover the
new functionality specified in this document.
10. Security Considerations
The security considerations described in [RFC5440] and
[I-D.crabbe-pce-pce-initiated-lsp] are applicable to this
specification. No additional security measure is required.
11. IANA Considerations
IANA is requested to allocate a ERO subobject type (recommended value
= 5) for the SR-ERO subobject.
This document also defines new Error-Values for the following new
error conditions:
Error-Type Meaning
10 Reception of an invalid object
Error-value=2: Bad label value
Error-value=3: Unsupported number of Segment ERO
subobjects
12. Acknowledgement
We like to thank George Swallow for the valuable comments.
13. References
13.1. Normative References
[I-D.crabbe-pce-pce-initiated-lsp]
Crabbe, E., Minei, I., Sivabalan, S., and R. Varga, "PCEP
Extensions for PCE-initiated LSP Setup in a Stateful PCE
Model", draft-crabbe-pce-pce-initiated-lsp-00 (work in
progress), October 2012.
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[I-D.crabbe-pce-stateful-pce-mpls-te]
Crabbe, E., Medved, J., Minei, I., and R. Varga, "Stateful
PCE extensions for MPLS-TE LSPs",
draft-crabbe-pce-stateful-pce-mpls-te-01 (work in
progress), May 2013.
[I-D.ietf-pce-pcep-mib]
Koushik, K., Stephan, E., Zhao, Q., King, D., and J.
Hardwick, "PCE communication protocol (PCEP) Management
Information Base", draft-ietf-pce-pcep-mib-04 (work in
progress), February 2013.
[I-D.ietf-pce-stateful-pce]
Crabbe, E., Medved, J., Minei, I., and R. Varga, "PCEP
Extensions for Stateful PCE",
draft-ietf-pce-stateful-pce-04 (work in progress),
May 2013.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[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.
[RFC5462] Andersson, L. and R. Asati, "Multiprotocol Label Switching
(MPLS) Label Stack Entry: "EXP" Field Renamed to "Traffic
Class" Field", RFC 5462, February 2009.
[SR-ARCH] Filsfils, C., Previdi, S., Bashandy, A., and M. Horneffer,
"Segment Routing Architecture",
draft-filsfils-previdi-segment-routing-00.txt (work in
progress), June 2013.
[SR-ISIS] Previdi, S., Filsfils, C., Bashandy, A., and M. Horneffer,
"Segment Routing with IS-IS Routing Protocol",
draft-previdi-filsfils-isis-segment-routing-00.txt (work
in progress), September 2013.
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Internet-Draft PCEP Extensions for Segment Routing June 2013
13.2. Informative References
[RFC3209] Awduche, D., Berger, L., Gan, D., Li, T., Srinivasan, V.,
and G. Swallow, "RSVP-TE: Extensions to RSVP for LSP
Tunnels", RFC 3209, December 2001.
[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.
[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.
[RFC5305] Li, T. and H. Smit, "IS-IS Extensions for Traffic
Engineering", RFC 5305, October 2008.
[RFC5394] Bryskin, I., Papadimitriou, D., Berger, L., and J. Ash,
"Policy-Enabled Path Computation Framework", RFC 5394,
December 2008.
[RFC5557] Lee, Y., Le Roux, JL., King, D., and E. Oki, "Path
Computation Element Communication Protocol (PCEP)
Requirements and Protocol Extensions in Support of Global
Concurrent Optimization", RFC 5557, July 2009.
Authors' Addresses
Siva Sivabalan
Cisco Systems, Inc.
2000 Innovation Drive
Kanata, Ontario K2K 3E8
Canada
Email: msiva@cisco.com
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Internet-Draft PCEP Extensions for Segment Routing June 2013
Clarence Filsfils
Cisco Systems, Inc.
Pegasus Parc
De kleetlaan 6a, DIEGEM BRABANT 1831
BELGIUM
Email: cfilsfil@cisco.com
Jan Medved
Cisco Systems, Inc.
170 West Tasman Dr.
San Jose, CA 95134
US
Email: jmedved@cisco.com
Edward Crabbe
Google, Inc.
1600 Amphitheatre Parkway
Mountain View, CA 94043
US
Email: edward.crabbe@gmail.com
Robert Raszuk
NTT I3
101 S. Ellsworth Ave
San Mateo, CA 94401
US
Email: robert@raszuk.net
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