PCE Working Group M. Negi
Internet-Draft Z. Li
Intended status: Standards Track X. Geng
Expires: September 10, 2020 S. Peng
Huawei Technologies
March 9, 2020
PCEP Procedures and Protocol Extensions for Using PCE as a Central
Controller (PCECC) for P2MP LSPs
draft-dhody-pce-pcep-extension-pce-controller-p2mp-03
Abstract
The Path Computation Element (PCE) is a core component of Software-
Defined Networking (SDN) systems. It can compute optimal paths for
traffic across a network and can also update the paths to reflect
changes in the network or traffic demands.
The PCE has been identified as an appropriate technology for the
determination of the paths of point- to-multipoint (P2MP) TE Label
Switched Paths (LSPs).
PCE was developed to derive paths for MPLS P2MP LSPs, which are
supplied to the head end (root) of the LSP using PCEP. PCEP has been
proposed as a control protocol to allow the PCE to be fully enabled
as a central controller.
A PCE-based central controller (PCECC) can simplify the processing of
a distributed control plane by blending it with elements of SDN and
without necessarily completely replacing it. Thus, the P2MP LSP can
be calculated/setup/initiated and the label forwarding entries can
also be downloaded through a centralized PCE server to each network
devices along the P2MP path while leveraging the existing PCE
technologies as much as possible.
This document specifies the procedures and PCEP protocol extensions
for using the PCE as the central controller for P2MP TE LSP.
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 https://datatracker.ietf.org/drafts/current/.
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Internet-Drafts are draft documents valid for a maximum of six months
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This Internet-Draft will expire on September 10, 2020.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1. Requirements Language . . . . . . . . . . . . . . . . . . 5
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 5
3. Basic PCECC Mode . . . . . . . . . . . . . . . . . . . . . . 5
4. Procedures for Using the PCE as the Central Controller
(PCECC) for P2MP . . . . . . . . . . . . . . . . . . . . . . 5
4.1. Stateful PCE Model . . . . . . . . . . . . . . . . . . . 5
4.2. PCECC Capability Advertisement . . . . . . . . . . . . . 6
4.3. LSP Operations . . . . . . . . . . . . . . . . . . . . . 6
4.3.1. Basic PCECC LSP Setup . . . . . . . . . . . . . . . . 6
4.3.2. Central Control Instructions . . . . . . . . . . . . 7
4.3.2.1. Label Download . . . . . . . . . . . . . . . . . 7
4.3.2.2. Label Cleanup . . . . . . . . . . . . . . . . . . 8
4.3.3. PCE Initiated PCECC LSP . . . . . . . . . . . . . . . 9
4.3.4. PCECC LSP Update . . . . . . . . . . . . . . . . . . 9
4.3.5. Re Delegation and Cleanup . . . . . . . . . . . . . . 9
4.3.6. Synchronization of Central Controllers Instructions . 9
4.3.7. PCECC LSP State Report . . . . . . . . . . . . . . . 9
5. PCEP Objects . . . . . . . . . . . . . . . . . . . . . . . . 10
5.1. OPEN Object . . . . . . . . . . . . . . . . . . . . . . . 10
5.1.1. PCECC Capability sub-TLV . . . . . . . . . . . . . . 10
5.2. PATH-SETUP-TYPE TLV . . . . . . . . . . . . . . . . . . . 10
5.3. CCI Object . . . . . . . . . . . . . . . . . . . . . . . 10
6. Security Considerations . . . . . . . . . . . . . . . . . . . 11
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7. Manageability Considerations . . . . . . . . . . . . . . . . 11
7.1. Control of Function and Policy . . . . . . . . . . . . . 11
7.2. Information and Data Models . . . . . . . . . . . . . . . 11
7.3. Liveness Detection and Monitoring . . . . . . . . . . . . 11
7.4. Verify Correct Operations . . . . . . . . . . . . . . . . 11
7.5. Requirements On Other Protocols . . . . . . . . . . . . . 11
7.6. Impact On Network Operations . . . . . . . . . . . . . . 11
8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 11
8.1. PCECC-CAPABILITY TLV . . . . . . . . . . . . . . . . . . 12
8.2. PCEP-Error Object . . . . . . . . . . . . . . . . . . . . 12
9. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 12
10. References . . . . . . . . . . . . . . . . . . . . . . . . . 12
10.1. Normative References . . . . . . . . . . . . . . . . . . 12
10.2. Informative References . . . . . . . . . . . . . . . . . 13
Appendix A. Contributor Addresses . . . . . . . . . . . . . . . 16
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 16
1. Introduction
The Path Computation Element (PCE) [RFC4655] was developed to offload
path computation function from routers in an MPLS traffic-engineered
network. Since then, the role and function of the PCE has grown to
cover a number of other uses (such as GMPLS [RFC7025]) and to allow
delegated control [RFC8231] and PCE-initiated use of network
resources [RFC8281].
According to [RFC7399], Software-Defined Networking (SDN) refers to a
separation between the control elements and the forwarding components
so that software running in a centralized system, called a
controller, can act to program the devices in the network to behave
in specific ways. A required element in an SDN architecture is a
component that plans how the network resources will be used and how
the devices will be programmed. It is possible to view this
component as performing specific computations to place traffic flows
within the network given knowledge of the availability of network
resources, how other forwarding devices are programmed, and the way
that other flows are routed. This is the function and purpose of a
PCE, and the way that a PCE integrates into a wider network control
system (including an SDN system) is presented in [RFC7491].
In early PCE implementations, where the PCE was used to derive paths
for MPLS Label Switched Paths (LSPs), paths were requested by network
elements (known as Path Computation Clients (PCCs)), and the results
of the path computations were supplied to network elements using the
Path Computation Element Communication Protocol (PCEP) [RFC5440].
This protocol was later extended to allow a PCE to send unsolicited
requests to the network for LSP establishment [RFC8281].
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[RFC8283] introduces the architecture for PCE as a central controller
as an extension of the architecture described in [RFC4655] and
assumes the continued use of PCEP as the protocol used between PCE
and PCC. [RFC8283] further examines the motivations and
applicability for PCEP as a Southbound Interface (SBI), and
introduces the implications for the protocol.
A PCE-based central controller (PCECC) can simplify the processing of
a distributed control plane by blending it with elements of SDN and
without necessarily completely replacing it. Thus, the LSP can be
calculated/setup/initiated and the label forwarding entries can also
be downloaded through a centralized PCE server to each network
devices along the path while leveraging the existing PCE technologies
as much as possible.
[I-D.ietf-pce-pcep-extension-for-pce-controller] specify the
procedures and PCEP protocol extensions for using the PCE as the
central controller for static P2P LSPs, where LSPs can be provisioned
as explicit label instructions at each hop on the end-to-end path.
Each router along the path must be told what label-forwarding
instructions to program and what resources to reserve. The PCE-based
controller keeps a view of the network and determines the paths of
the end-to-end LSPs, and the controller uses PCEP to communicate with
each router along the path of the end-to-end LSP.
[RFC4857] describes how to set up point-to-multipoint (P2MP) Traffic
Engineering Label Switched Paths (TE LSPs) for use in Multiprotocol
Label Switching (MPLS) and Generalized MPLS (GMPLS) networks. The
PCE has been identified as a suitable application for the computation
of paths for P2MP TE LSPs ([RFC5671]). The extensions of PCEP to
request path computation for P2MP TE LSPs are described in [RFC8306].
Further [RFC8623] specify the extensions that are necessary in order
for the deployment of stateful PCEs to support P2MP TE LSPs as well
as the setup, maintenance and teardown of PCE-initiated P2MP LSPs
under the stateful PCE model.
This document extends
[I-D.ietf-pce-pcep-extension-for-pce-controller] to specify the
procedures and PCEP protocol extensions for using the PCE as the
central controller for static P2MP LSPs, where LSPs can be
provisioned as explicit label instructions at each hop on the end-to-
end path with an added functionality of a P2MP branch node. As per
[RFC4875], a branch node is an LSR that replicates the incoming data
on to one or more outgoing interfaces.
[I-D.ietf-teas-pcecc-use-cases] describes the use cases for P2MP in
PCECC architecture.
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1.1. Requirements Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in BCP
14 [RFC2119] [RFC8174] when, and only when, they appear in all
capitals, as shown here.
2. Terminology
Terminologies used in this document is same as described in the draft
[RFC8283] and [I-D.ietf-teas-pcecc-use-cases].
3. Basic PCECC Mode
As described in [I-D.ietf-pce-pcep-extension-for-pce-controller], in
this mode LSPs are provisioned as explicit label instructions at each
hop on the end-to-end path. Each router along the path must be told
what label forwarding instructions to program and what resources to
reserve. The controller uses PCEP to communicate with each router
along the path of the end-to-end LSP. Note that the PCE-based
controller will take responsibility for managing some part of the
MPLS label space for each of the routers that it controls, and may
taker wider responsibility for partitioning the label space for each
router and allocating different parts for different uses. This is
also described in section 3.1.2. of [RFC8283]. For the purpose of
this document, it is assumed that label range to be used by a PCE is
known and set on both PCEP peers. A future extension could add this
capability to advertise the range via possible PCEP extensions as
well.
This document extends the functionality to include support for
central control instruction for replication at the branch nodes.
The rest of processing is similar to the existing stateful PCE
mechanism for P2MP.
4. Procedures for Using the PCE as the Central Controller (PCECC) for
P2MP
4.1. Stateful PCE Model
Active stateful PCE is described in [RFC8231] and extended for P2MP
[RFC8623]. PCE as a central controller (PCECC) reuses existing
Active stateful PCE mechanism as much as possible to control the LSP.
[I-D.ietf-pce-pcep-extension-for-pce-controller] extends PCEP
messages - PCRpt, PCInitiate, PCUpd message for the Central
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Controller's Instructions (CCI) (label forwarding instructions in the
context of this document). This documents specify the procedure for
additional instruction for branch node needed for P2MP.
4.2. PCECC Capability Advertisement
As per [I-D.ietf-pce-pcep-extension-for-pce-controller], during PCEP
Initialization Phase, PCEP Speakers (PCE or PCC) advertise their
support of PCECC extensions by sending a PATH-SETUP-TYPE-CAPABILITY
TLV in the OPEN object with this PST=PCECC included in the PST list.
[I-D.ietf-pce-pcep-extension-for-pce-controller] also defines the
PCECC Capability sub-TLV. A new M-bit is added in PCECC-CAPABILITY
TLV to indicate support for PCECC-P2MP. A PCC MUST set M-bit in
PCECC-CAPABILITY TLV and include STATEFUL-PCE-CAPABILITY TLV with
P2MP bits set ([RFC8623]) in OPEN Object to support the PCECC P2MP
extensions defined in this document. If M-bit is set in PCECC-
CAPABILITY TLV and N-bit in STATEFUL-PCE-CAPABILITY TLV is not set in
OPEN Object, PCE SHOULD send a PCErr message with Error-Type=19
(Invalid Operation) and Error-value=TBD (P2MP capability was not
advertised) and terminate the session.
4.3. LSP Operations
The PCEP messages pertaining to PCECC MUST include PATH-SETUP-TYPE
TLV [RFC8408] with PST=PCECC
[I-D.ietf-pce-pcep-extension-for-pce-controller] in the SRP object to
clearly identify the PCECC LSP is intended.
4.3.1. Basic PCECC LSP Setup
In order to setup a P2MP LSP based on PCECC mechanism, a PCC MUST
delegate the P2MP LSP by sending a PCRpt message with PST set for
PCECC and D (Delegate) flag (see [RFC8623]) set in the LSP object.
P2MP-LSP-IDENTIFIER TLV [RFC8623] MUST be included for PCECC LSP, the
tuple uniquely identifies the P2MP LSP in the network. As per
[I-D.ietf-pce-pcep-extension-for-pce-controller], the LSP object is
included in central controller's instructions (label download) to
identify the PCECC LSP for this instruction.
When a PCE receives PCRpt message with D flags and PST Type set, it
calculates the P2MP tree and assigns labels along the path; and set
up the path by sending PCInitiate message to each node along the path
of the LSP, similar to
[I-D.ietf-pce-pcep-extension-for-pce-controller]. The new extension
required is the instructions on the branch nodes for replications to
more than one outgoing interfaces with respective labels. The rest
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of the operations remains same as
[I-D.ietf-pce-pcep-extension-for-pce-controller] and [RFC8623].
4.3.2. Central Control Instructions
The new central controller's instructions (CCI) for the label
operations in PCEP is done via the PCInitiate message as described in
[I-D.ietf-pce-pcep-extension-for-pce-controller], by defining a new
PCEP Objects for CCI operations. Local label range of each PCC is
assumed to be known at both the PCC and the PCE.
4.3.2.1. Label Download
In order to setup an LSP based on PCECC, the PCE sends a PCInitiate
message to each node along the path to download the Label instruction
as described in Section 4.3.1.
The CCI object MUST be included, along with the LSP object in the
PCInitiate message. As per
[I-D.ietf-pce-pcep-extension-for-pce-controller], there are at most 2
instances of CCI object in the PCInitiate message. For PCECC-P2MP
operations, multiple instances of CCI object for out-labels is
allowed. Similarly to acknowledge the central controller
instructions, the PCRpt message allows multiple instances of CCI
object for PCECC-P2MP operations.
The LSP-IDENTIFIER TLV MUST be included in LSP object. The SPEAKER-
ENTITY-ID TLV SHOULD be included in LSP object.
As described in [I-D.ietf-pce-pcep-extension-for-pce-controller], if
a node (PCC) receives a PCInitiate message which includes a Label to
download as part of CCI, that is out of the range set aside for the
PCE, it send a PCErr message with Error-type=TBD (PCECC failure) and
Error-value=TBD (Label out of range). If a PCC receives a PCInitiate
message but failed to download the Label entry, it sends a PCErr
message with Error-type=TBD (PCECC failure) and Error-value=TBD
(instruction failed).
Consider the example in the [I-D.ietf-teas-pcecc-use-cases] -
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+----------+
| R1 | Root node of the P2MP TE LSP
+----------+
|6000
+----------+
Transit Node | R2 |
branch +----------+
* | * *
9001* | * *9002
* | * *
+-----------+ | * +-----------+
| R4 | | * | R5 | Transit Nodes
+-----------+ | * +-----------+
* | * * +
9003* | * * +9004
* | * * +
+-----------+ +-----------+
| R3 | | R6 | Leaf Node
+-----------+ +-----------+
9005|
+-----------+
| R8 | Leaf Node
+-----------+
PCECC would provision each node along the path and assign incoming
and outgoing labels from R1 to {R6, R8} with the path: {R1, 6000},
{6000, R2, {9001,9002}}, {9001, R4, 9003}, {9002, R5, 9004} {9003,
R3, 9005}, {9004, R6}, {9005, R8}. The operations on all nodes except
R2 are same as [I-D.ietf-pce-pcep-extension-for-pce-controller]. The
branch node (R2) needs to be instructed to replicate two copies of
the incoming packet, and sent towards R4 and R5 with 9001 and 9002
labels respectively). This done via including 3 instances of CCI
objects in the PCEP messages, one for each label in the example, 6000
for incoming and 9001/9002 for outgoing (along with remote nexthop).
The message and procedure remains exactly as
[I-D.ietf-pce-pcep-extension-for-pce-controller] with only
distinction that more than one outgoing CCI MAY be present for the
P2MP LSP.
4.3.2.2. Label Cleanup
In order to delete an P2MP LSP based on PCECC, the PCE sends a
central controller instructions via a PCInitiate message to each node
along the path of the LSP to cleanup the Label forwarding instruction
as per [I-D.ietf-pce-pcep-extension-for-pce-controller]. In case of
branch nodes all instances of CCIs needs to be present in the PCEP
message.
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4.3.3. PCE Initiated PCECC LSP
The LSP Instantiation operation is same as defined in [RFC8281] and
[RFC8623].
In order to setup a P2MP PCE Initiated LSP based on the PCECC
mechanism, a PCE sends PCInitiate message with Path Setup Type set
for PCECC (see Section 5.2) to the Ingress PCC (root).
The Ingress PCC MUST also set D (Delegate) flag (see [RFC8231]) and C
(Create) flag (see [RFC8281]) in LSP object of PCRpt message. The
PCC responds with first PCRpt message with the status as "GOING-UP"
and assigned PLSP-ID.
As described in [I-D.ietf-pce-pcep-extension-for-pce-controller], the
label forwarding instructions from PCECC are send after the initial
PCInitiate and PCRpt exchange. This is done so that the PLSP-ID and
other LSP identifiers can be obtained from the ingress and can be
included in the label forwarding instruction in the next PCInitiate
message. The rest of the PCECC LSP setup operations are same as
those described in Section 4.3.1.
4.3.4. PCECC LSP Update
In case of a modification of PCECC P2MP LSP with a new path, the
procedure and instructions as described in
[I-D.ietf-pce-pcep-extension-for-pce-controller] apply.
4.3.5. Re Delegation and Cleanup
In case of a redelegation and cleanup of PCECC P2MP LSP, the
procedure and instructions as described in
[I-D.ietf-pce-pcep-extension-for-pce-controller] apply.
4.3.6. Synchronization of Central Controllers Instructions
The procedure and instructions are as per
[I-D.ietf-pce-pcep-extension-for-pce-controller].
4.3.7. PCECC LSP State Report
An Ingress PCC MAY choose to apply any OAM mechanism to check the
status of LSP in the Data plane and MAY further send its status in
PCRpt message (as per [RFC8623]) to the PCE.
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5. PCEP Objects
5.1. OPEN Object
5.1.1. PCECC Capability sub-TLV
The PCECC-CAPABILITY sub-TLV is an optional TLV for use in the OPEN
Object for PCECC capability advertisement in PATH-SETUP-TYPE-
CAPABILITY TLV as specified in
[I-D.ietf-pce-pcep-extension-for-pce-controller].
This document adds a new flag (M-bit) in PCECC-CAPABILITY sub-TLV to
indicate the support for P2MP in PCECC. A PCC MUST set M-bit in
PCECC-CAPABILITY sub-TLV and set the N (P2MP-CAPABILITY), M (P2MP-
LSP-UPDATE-CAPABILITY), and P (P2MP-LSP-INSTANTIATION-CAPABILITY) (as
per [RFC8623]) in STATEFUL-PCE-CAPABILITY TLV [RFC8231] to support
the PCECC P2MP extensions defined in this document. If M-bit is set
in PCECC-CAPABILITY sub-TLV and the P2MP bits in STATEFUL-PCE-
CAPABILITY TLV are not set in OPEN Object, PCE SHOULD send a PCErr
message with Error-Type=19 (Invalid Operation) and Error-
value=TBD(P2MP capability was not advertised) and terminate the
session.
5.2. PATH-SETUP-TYPE TLV
The PATH-SETUP-TYPE TLV is defined in [RFC8408];
[I-D.ietf-pce-pcep-extension-for-pce-controller] defines a PST value
for PCECC, which is also used for P2MP.
5.3. CCI Object
The Central Control Instructions (CCI) Object
[I-D.ietf-pce-pcep-extension-for-pce-controller] is used by the PCE
to specify the forwarding instructions (Label information in the
context of this document) to the PCC, and MAY be carried within
PCInitiate or PCRpt message for label download which defined Object
Type 1 for MPLS Label, which is also used for P2MP. The address TLVs
[I-D.ietf-pce-pcep-extension-for-pce-controller] associates the next-
hop information in case of an outgoing label.
If a node (PCC) receives a PCInitiate/PCUpd message with more than
one CCI with O-bit set for outgoing label and the node does not
support the P2MP branch/replication capability, it MUST respond with
PCErr message with Error-Type=2(Capability not supported).
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6. Security Considerations
The security considerations described in [RFC8231], [RFC8281],
[RFC8623], and [I-D.ietf-pce-pcep-extension-for-pce-controller] apply
to the extensions described in this document.
7. Manageability Considerations
7.1. Control of Function and Policy
A PCE or PCC implementation SHOULD allow to configure to enable/
disable PCECC P2MP capability as a global configuration.
7.2. Information and Data Models
[RFC7420] describes the PCEP MIB, this MIB can be extended to get the
PCECC capability status.
The PCEP YANG module [I-D.ietf-pce-pcep-yang] could be extended to
enable/disable PCECC P2MP capability.
7.3. Liveness Detection and Monitoring
Mechanisms defined in this document do not imply any new liveness
detection and monitoring requirements in addition to those already
listed in [RFC5440].
7.4. Verify Correct Operations
Mechanisms defined in this document do not imply any new operation
verification requirements in addition to those already listed in
[RFC5440] and [RFC8231].
7.5. Requirements On Other Protocols
PCEP extensions defined in this document do not put new requirements
on other protocols.
7.6. Impact On Network Operations
PCEP extensions defined in this document do not put new requirements
on network operations.
8. IANA Considerations
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8.1. PCECC-CAPABILITY TLV
[I-D.ietf-pce-pcep-extension-for-pce-controller] defines the PCECC-
CAPABILITY TLV and requests that IANA creates a registry to manage
the value of the PCECC-CAPABILITY TLV's Flag field. IANA is
requested to allocate a new bit in the PCECC-CAPABILITY TLV Flag
Field registry, as follows:
Bit Description Reference
TBD M((PCECC-P2MP-CAPABILITY)) This document
8.2. PCEP-Error Object
IANA is requested to allocate new error types and error values within
the "PCEP-ERROR Object Error Types and Values" sub-registry of the
PCEP Numbers registry for the following errors:
Error-Type Meaning
---------- -------
19 Invalid operation.
Error-value = TBD : P2MP capability was
not advertised
9. Acknowledgments
10. References
10.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/info/rfc2119>.
[RFC5440] Vasseur, JP., Ed. and JL. Le Roux, Ed., "Path Computation
Element (PCE) Communication Protocol (PCEP)", RFC 5440,
DOI 10.17487/RFC5440, March 2009,
<https://www.rfc-editor.org/info/rfc5440>.
[RFC7420] Koushik, A., Stephan, E., Zhao, Q., King, D., and J.
Hardwick, "Path Computation Element Communication Protocol
(PCEP) Management Information Base (MIB) Module",
RFC 7420, DOI 10.17487/RFC7420, December 2014,
<https://www.rfc-editor.org/info/rfc7420>.
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[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, <https://www.rfc-editor.org/info/rfc8174>.
[RFC8231] Crabbe, E., Minei, I., Medved, J., and R. Varga, "Path
Computation Element Communication Protocol (PCEP)
Extensions for Stateful PCE", RFC 8231,
DOI 10.17487/RFC8231, September 2017,
<https://www.rfc-editor.org/info/rfc8231>.
[RFC8281] Crabbe, E., Minei, I., Sivabalan, S., and R. Varga, "Path
Computation Element Communication Protocol (PCEP)
Extensions for PCE-Initiated LSP Setup in a Stateful PCE
Model", RFC 8281, DOI 10.17487/RFC8281, December 2017,
<https://www.rfc-editor.org/info/rfc8281>.
[RFC8623] Palle, U., Dhody, D., Tanaka, Y., and V. Beeram, "Stateful
Path Computation Element (PCE) Protocol Extensions for
Usage with Point-to-Multipoint TE Label Switched Paths
(LSPs)", RFC 8623, DOI 10.17487/RFC8623, June 2019,
<https://www.rfc-editor.org/info/rfc8623>.
[I-D.ietf-pce-pcep-extension-for-pce-controller]
Zhao, Q., Li, Z., Negi, M., Peng, S., and C. Zhou, "PCEP
Procedures and Protocol Extensions for Using PCE as a
Central Controller (PCECC) of LSPs", draft-ietf-pce-pcep-
extension-for-pce-controller-04 (work in progress), March
2020.
10.2. Informative References
[RFC4655] Farrel, A., Vasseur, J., and J. Ash, "A Path Computation
Element (PCE)-Based Architecture", RFC 4655,
DOI 10.17487/RFC4655, August 2006,
<https://www.rfc-editor.org/info/rfc4655>.
[RFC4857] Fogelstroem, E., Jonsson, A., and C. Perkins, "Mobile IPv4
Regional Registration", RFC 4857, DOI 10.17487/RFC4857,
June 2007, <https://www.rfc-editor.org/info/rfc4857>.
[RFC4875] Aggarwal, R., Ed., Papadimitriou, D., Ed., and S.
Yasukawa, Ed., "Extensions to Resource Reservation
Protocol - Traffic Engineering (RSVP-TE) for Point-to-
Multipoint TE Label Switched Paths (LSPs)", RFC 4875,
DOI 10.17487/RFC4875, May 2007,
<https://www.rfc-editor.org/info/rfc4875>.
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[RFC5671] Yasukawa, S. and A. Farrel, Ed., "Applicability of the
Path Computation Element (PCE) to Point-to-Multipoint
(P2MP) MPLS and GMPLS Traffic Engineering (TE)", RFC 5671,
DOI 10.17487/RFC5671, October 2009,
<https://www.rfc-editor.org/info/rfc5671>.
[RFC7025] Otani, T., Ogaki, K., Caviglia, D., Zhang, F., and C.
Margaria, "Requirements for GMPLS Applications of PCE",
RFC 7025, DOI 10.17487/RFC7025, September 2013,
<https://www.rfc-editor.org/info/rfc7025>.
[RFC7399] Farrel, A. and D. King, "Unanswered Questions in the Path
Computation Element Architecture", RFC 7399,
DOI 10.17487/RFC7399, October 2014,
<https://www.rfc-editor.org/info/rfc7399>.
[RFC7491] King, D. and A. Farrel, "A PCE-Based Architecture for
Application-Based Network Operations", RFC 7491,
DOI 10.17487/RFC7491, March 2015,
<https://www.rfc-editor.org/info/rfc7491>.
[RFC8283] Farrel, A., Ed., Zhao, Q., Ed., Li, Z., and C. Zhou, "An
Architecture for Use of PCE and the PCE Communication
Protocol (PCEP) in a Network with Central Control",
RFC 8283, DOI 10.17487/RFC8283, December 2017,
<https://www.rfc-editor.org/info/rfc8283>.
[RFC8306] Zhao, Q., Dhody, D., Ed., Palleti, R., and D. King,
"Extensions to the Path Computation Element Communication
Protocol (PCEP) for Point-to-Multipoint Traffic
Engineering Label Switched Paths", RFC 8306,
DOI 10.17487/RFC8306, November 2017,
<https://www.rfc-editor.org/info/rfc8306>.
[RFC8408] Sivabalan, S., Tantsura, J., Minei, I., Varga, R., and J.
Hardwick, "Conveying Path Setup Type in PCE Communication
Protocol (PCEP) Messages", RFC 8408, DOI 10.17487/RFC8408,
July 2018, <https://www.rfc-editor.org/info/rfc8408>.
[I-D.ietf-teas-pcecc-use-cases]
Zhao, Q., Li, Z., Khasanov, B., Dhody, D., Ke, Z., Fang,
L., Zhou, C., Communications, T., Rachitskiy, A., and A.
Gulida, "The Use Cases for Path Computation Element (PCE)
as a Central Controller (PCECC).", draft-ietf-teas-pcecc-
use-cases-05 (work in progress), March 2020.
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[I-D.ietf-pce-pcep-yang]
Dhody, D., Hardwick, J., Beeram, V., and J. Tantsura, "A
YANG Data Model for Path Computation Element
Communications Protocol (PCEP)", draft-ietf-pce-pcep-
yang-13 (work in progress), October 2019.
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Appendix A. Contributor Addresses
Dhruv Dhody
Huawei Technologies
Divyashree Techno Park, Whitefield
Bangalore, Karnataka 560066
India
EMail: dhruv.ietf@gmail.com
Udayasree Palle
EMail: udayasreereddy@gmail.com
Authors' Addresses
Mahendra Singh Negi
Huawei Technologies
Divyashree Techno Park, Whitefield
Bangalore, Karnataka 560066
India
EMail: mahend.ietf@gmail.com
Zhenbin Li
Huawei Technologies
Huawei Bld., No.156 Beiqing Rd.
Beijing 100095
China
EMail: lizhenbin@huawei.com
Xuesong Geng
Huawei Technologies
China
EMail: gengxuesong@huawei.com
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Shuping Peng
Huawei Technologies
Huawei Bld., No.156 Beiqing Rd.
Beijing 100095
China
EMail: pengshuping@huawei.com
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