Internet DRAFT - draft-koldychev-pce-operational
draft-koldychev-pce-operational
PCE Working Group M. Koldychev
Internet-Draft Cisco Systems, Inc.
Intended status: Standards Track S. Sivabalan
Expires: July 8, 2023 Ciena Corporation
S. Peng
Huawei Technologies
D. Achaval
Nokia
H. Kotni
Juniper Networks, Inc
January 4, 2023
PCEP Operational Clarification
draft-koldychev-pce-operational-07
Abstract
This document updates, simplifies and clarifies certain aspects of
the PCEP protocol. The content of this document has been compiled
based on several interop exercises.
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.
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/.
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 July 8, 2023.
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Copyright Notice
Copyright (c) 2023 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents
(https://trustee.ietf.org/license-info) in effect on the date of
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described in the Simplified BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. PCEP LSP Database . . . . . . . . . . . . . . . . . . . . . . 4
3.1. Structure . . . . . . . . . . . . . . . . . . . . . . . . 4
3.2. Synchronization . . . . . . . . . . . . . . . . . . . . . 4
3.3. Stateful Bringup . . . . . . . . . . . . . . . . . . . . 5
3.3.1. Updates to RFC 8231 . . . . . . . . . . . . . . . . . 5
3.4. Successful MBB . . . . . . . . . . . . . . . . . . . . . 6
3.5. Aborted MBB . . . . . . . . . . . . . . . . . . . . . . . 7
4. PCEP Association Database . . . . . . . . . . . . . . . . . . 8
4.1. 2 LSPs in same Association . . . . . . . . . . . . . . . 9
4.2. Switch Association during MBB . . . . . . . . . . . . . . 10
5. Computation Constraints . . . . . . . . . . . . . . . . . . . 11
6. Use of SR-RRO and SRv6-RRO objects . . . . . . . . . . . . . 11
7. Security Considerations . . . . . . . . . . . . . . . . . . . 12
8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 12
9. Acknowledgement . . . . . . . . . . . . . . . . . . . . . . . 12
10. Normative References . . . . . . . . . . . . . . . . . . . . 12
Appendix A. Contributors . . . . . . . . . . . . . . . . . . . . 13
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 14
1. Introduction
The PCEP protocol started off being purely stateless with PCReq and
PCReply messages, see Path Computation Element (PCE) Communication
Protocol (PCEP) [RFC5440]. Stateless PCEP operates in a "pull"
model, i.e., PCC has to periodically ask the PCE for updates to the
path, even if the path has not changed.
Stateful PCEP was later introduced in PCEP Extensions for the
Stateful PCE Model [RFC8231]. Stateful PCEP operates in a "push"
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model, where the PCC can register with PCE to receive future updates
about the path, and there is no need to ask the PCE periodically.
The current document serves to optimize the original procedure in
[RFC8231] to optionally drop the PCReq and PCReply exchange, which
greatly simplifies implementation and optimizes the protocol.
Due to different interpretations of PCEP standards, it was found that
implementations often had to adjust their behavior in order to
interoperate. The current document serves to clarify certain aspects
of PCEP to make it easier to produce interoperable implementations of
PCEP.
2. Terminology
The following terminologies are used in this document:
PCC: Path Computation Client. Any client application requesting a
path computation to be performed by a Path Computation Element.
PCE: Path Computation Element. An entity (component, application,
or network node) that is capable of computing a network path or
route based on a network graph and applying computational
constraints.
PCEP: Path Computation Element Protocol.
MBB: Make-Before-Break. A procedure during which the head-end of a
traffic-engineered path wishes to move traffic to a new path
without losing any traffic, by first "making" a new path and then
"breaking" the old path.
Association parameters: As described in [RFC8697], the combination
of the mandatory fields Association type, Association ID and
Association Source in the ASSOCIATION object uniquely identify the
association group. If the optional TLVs - Global Association
Source or Extended Association ID are included, then they MUST be
included in combination with mandatory fields to uniquely identify
the association group.
Association information: As described in [RFC8697], the ASSOCIATION
object could also include other optional TLVs based on the
association types, that provides 'information' related to the
association type.
ERO: Explicit Route Object is the path of the LSP encoded into a
PCEP object. To represent an empty ERO object, i.e., without any
subobjects, we use the notation "ERO={}". To represent an ERO
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object containing some given sequence of subobjects, we use the
notation "ERO={A}".
3. PCEP LSP Database
We use the concept of the LSP-DB, as a database of actual LSP state
in the network, to illustrate the internal state of PCEP speakers in
response to various PCEP messages.
Note that the term "LSP", which stands for "Label Switched Path", if
taken too literally would restrict our discussion to MPLS dataplane
only. We take the term "LSP" to apply to non-MPLS paths as well, to
avoid changing the name. Alternatively, we could rename LSP to
"Instance".
3.1. Structure
LSP-DB contains two types of objects: LSPs and Tunnels. An LSP is
identified by the LSP-IDENTIFIERS TLV. A Tunnel is identified by the
PLSP-ID in the LSP object and/or the SYMBOLIC-NAME. See [RFC8231].
A Tunnel may or may not be an actual tunnel on the router. For
example, working and protect paths can be implemented as a single
tunnel interface, but in PCEP we would refer to them as two different
Tunnels, because they would have different PLSP-IDs.
An LSP can be thought of as a instance of a Tunnel. In steady-state,
a Tunnel has only one LSP, but during make-before-break (see
[RFC3209]) it can have multiple LSPs, to represent both new and old
instances that exist simultaneously for a time.
3.2. Synchronization
Both PCE and PCC maintain their separate copies of the LSP-DB. The
PCE LSP-DB is only modified by PCRpt messages, no other PCEP message
may modify the PCE LSP-DB. The PCC LSP-DB is built from actual
forwarding state that PCC has installed. PCC uses PCRpt messages to
synchronize its local LSP-DB to the PCE.
The PCE MUST always act on the latest state of the PCE LSP DB. Note
that this does not mean that the PCE cannot use information from
outside of LSP-DB. For example, the PCE can use other mechanisms to
collect traffic statistics and use them in the computation. However,
these traffic statistics are not part of the LSP-DB, but only
reference it.
The LSP-DB on both the PCC and the PCE only stores the actual state
in the network, it does not store the desired state. For example,
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consider the case of PCE Initiated LSP, configured on the PCE. When
the operator modifies the configuration of this LSP, that is a change
in desired state. The actual state has not yet changed, so LSP-DB is
not modified yet. The LSP-DB is only modified after the PCE sends
PCInit/PCUpd message to the PCC and the PCC decides to act on that
message. When the PCC acts on a message from a PCE, it would update
its own PCC LSP DB and send a PCRpt to the PCE(s) to synchronize the
change. When the PCE receives the PCRpt msg, it updates its own PCE
LSP DB. After this, the PCC LSP-DB and PCE LSP-DB are in sync.
3.3. Stateful Bringup
[RFC8231] Section 5.8.2, allows delegation of an LSP in operationally
down state, but at the same time mandates the use of PCReq, before
sending PCRpt. In this document, we would like to make it clear that
sending PCReq is optional.
We shall refer to the process of sending PCReq before PCRpt as
"stateless bringup". In reality, stateless bringup introduces
overhead and is not possible to enforce from the PCE, because the
stateless PCE is not required to keep any per-LSP state about
previous PCReq messages. It was found that many vendors choose to
ignore this requirement and send the PCRpt directly, without going
through PCReq. Even though this behavior is against [RFC8231], it
offers some advantages and simplifications, as will be explained in
this section. This document therefore updates [RFC8231].
Even though all the major vendors today are moving to the stateful
PCE model, it does not deprecate the need for stateless PCEP. The
key property of stateless PCEP is that PCReq messages do not modify
the state of the PCE LSP-DB. Therefore, PCReq messages are useful
for many OAM ping/traceroute applications where the PCC wishes to
probe the network topology without having any effect on the existing
LSPs.
3.3.1. Updates to RFC 8231
[RFC8231] Section 5.8.2, says "The only explicit way for a PCC to
request a path from the PCE is to send a PCReq message. The PCRpt
message MUST NOT be used by the PCC to attempt to request a path from
the PCE." In this document we update [RFC8231] to remove the quoted
text.
As part of the new bringup procedure, the PCC MAY delegate an empty
LSP (no ERO or empty ERO) to the PCE and then wait for the PCE to
send PCUpd, without sending PCReq. We shall refer to this process as
"stateful bringup". The PCE MUST support the original stateless
bringup, for backward compatibility purposes. Supporting stateful
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bringup should not require introducing any new behavior on the PCE,
because as mentioned earlier, the PCE does not modify LSP-DB state
based on PCReq messages. So whether the PCE has received a PCReq or
not, it would process the PCRpt all the same.
An example of stateful bringup follows. In our example the PCC
starts off by using LSP-ID of 0. The value 0 does not hold any
special meaning, any other 16-bit value could have been used.
PCC has no LSP yet, but wants to establish a path. PCC sends
PCRpt(R-FLAG=0, D-flag=1, OPER-FLAG=DOWN, PLSP-ID=100, LSP-ID=0,
ERO={}).
+---------------------------------------------------------------+
| TUNNEL | LSP |
+-----------------+---------------------------------------------+
| PLSP-ID=100 | LSP-ID=0, D-flag=1, OPER=DOWN, ERO={} |
+---------------------------------------------------------------+
Figure 1: Content of LSP DB
PCC received a PCUpd from the PCE and has decided to install the
ERO={A} from that PCUpd. PCC sends PCRpt(R-FLAG=0, D-flag=1, OPER-
FLAG=UP, PLSP-ID=100, LSP-ID=0, ERO={A}).
+---------------------------------------------------------------+
| TUNNEL | LSP |
+-----------------+---------------------------------------------+
| PLSP-ID=100 | LSP-ID=0, D-flag=1, OPER=UP, ERO={A} |
+---------------------------------------------------------------+
Figure 2: Content of LSP DB
3.4. Successful MBB
Below we give an example of doing MBB to switch the Tunnel from one
path to another. We represent the path encoded into the ERO object
as ERO={A} and ERO={B}.
PCC has an existing LSP in UP state, with LSP-ID=2. PCC sends
PCRpt(R-FLAG=0, PLSP-ID=100, LSP-ID=2, ERO={A}, OPER-FLAG=UP).
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+---------------------------------------------------------------+
| TUNNEL | LSP |
+-----------------+---------------------------------------------+
| PLSP-ID=100 | LSP-ID=2, ERO={A}, OPER=UP |
+---------------------------------------------------------------+
Figure 3: Content of LSP DB
PCC initiates the MBB procedure by creating a new LSP with LSP-ID=3.
It does not matter what triggered the creation of the new LSP, it
could have been due to a new path received via PCUpd (if the given
Tunnel is delegated), or it could have been local computation on the
PCC (if the Tunnel is locally computed on the PCC), or it could have
been a change in configuration on the PCC (if the Tunnel's path is
explicitly configured on the PCC). It is important to emphasize that
the procedure for updating the LSP-DB is common, regardless of the
trigger that caused the change.
PCC sends PCRpt(R-FLAG=0, PLSP-ID=100, LSP-ID=3, ERO={B}, OPER-
FLAG=UP).
+---------------------------------------------------------------+
| TUNNEL | LSP |
+-----------------+---------------------------------------------+
| PLSP-ID=100 | LSP-ID=2, ERO={A}, OPER=UP |
| | LSP-ID=3, ERO={B}, OPER=UP |
+---------------------------------------------------------------+
Figure 4: Content of LSP DB
After traffic has successfully switched to the new LSP, the PCC
cleans up the old LSP. PCC sends PCRpt(R-FLAG=1, PLSP-ID=100, LSP-
ID=2).
+---------------------------------------------------------------+
| TUNNEL | LSP |
+-----------------+---------------------------------------------+
| PLSP-ID=100 | LSP-ID=3, ERO={B}, OPER=UP |
+---------------------------------------------------------------+
Figure 5: Content of LSP DB
3.5. Aborted MBB
The MBB process can abort when the newly created LSP is destroyed
before it is installed as traffic carrying. This scenario is
described below.
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PCC has an existing LSP in UP state, with LSP-ID=2. PCC sends
PCRpt(R-FLAG=0, OPER-FLAG=UP, PLSP-ID=100, LSP-ID=2).
+---------------------------------------------------------------+
| TUNNEL | LSP |
+-----------------+---------------------------------------------+
| PLSP-ID=100 | LSP-ID=2, OPER=UP |
+---------------------------------------------------------------+
Figure 6: Content of LSP DB
MBB procedure is initiated, a new LSP is created with LSP-ID=3. LSP
is currently being established, so its oper state is DOWN. PCC sends
PCRpt(R-FLAG=0, OPER-FLAG=DOWN, PLSP-ID=100, LSP-ID=3).
+---------------------------------------------------------------+
| TUNNEL | LSP |
+-----------------+---------------------------------------------+
| PLSP-ID=100 | LSP-ID=2, OPER=UP |
| | LSP-ID=3, OPER=DOWN |
+---------------------------------------------------------------+
Figure 7: Content of LSP DB
MBB procedure is aborted. PCC sends PCRpt(R-FLAG=1, PLSP-ID=100,
LSP-ID=3).
+---------------------------------------------------------------+
| TUNNEL | LSP |
+-----------------+---------------------------------------------+
| PLSP-ID=100 | LSP-ID=2, OPER=UP |
+---------------------------------------------------------------+
Figure 8: Content of LSP DB
4. PCEP Association Database
PCEP Association is a group of zero or more LSPs.
The PCE ASSO DB is populated by PCRpt messages and/or via
configuration on the PCE itself. An Association is identified by the
Association Parameters. The Association parameters contain many
fields, so for convenience we will group all the fields into a single
value. We will use ASSO_PARAM=A, ASSO_PARAM=B, to refer to different
PCEP Associations: A and B, respectively.
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4.1. 2 LSPs in same Association
Below, we give an example to illustrate how LSPs join the same
Association.
PCC creates the first LSP. PCC sends PCRpt(R-FLAG=0, PLSP-ID=100,
LSP-ID=1, ASSO_PARAM=A, ASSO_R_FLAG=0).
+---------------------------------------------------------------+
| ASSO | LSP |
+-----------------+---------------------------------------------+
| ASSO_PARAM=A | PLSP-ID=100, LSP-ID=1 |
+---------------------------------------------------------------+
Figure 9: Content of PCE ASSO DB
PCC creates the second LSP. PCC sends PCRpt(R-FLAG=0, PLSP-ID=200,
LSP-ID=1, ASSO_PARAM=A, ASSO_R_FLAG=0).
+---------------------------------------------------------------+
| ASSO | LSP |
+-----------------+---------------------------------------------+
| ASSO_PARAM=A | PLSP-ID=100, LSP-ID=1 |
| | PLSP-ID=200, LSP-ID=1 |
+---------------------------------------------------------------+
Figure 10: Content of PCE ASSO DB
PCC updates the first LSP, the PCC is NOT REQUIRED to send the
ASSOCIATION object in this PCRpt, since the LSP is already in the
Association. PCC sends PCRpt(R-FLAG=0, PLSP-ID=100, LSP-ID=1). The
content of the PCE ASSO DB is unchanged. Note that the PCC sends the
ASSOCIATION OBJECT in the first PCRpt during SYNC state, even if it
has already issued a PCRpt with the association object sometime in
the past with this PCE. The synchronization steps outlined in
[RFC8697] are to be followed.
+---------------------------------------------------------------+
| ASSO | LSP |
+-----------------+---------------------------------------------+
| ASSO_PARAM=A | PLSP-ID=100, LSP-ID=1 |
| | PLSP-ID=200, LSP-ID=1 |
+---------------------------------------------------------------+
Figure 11: Content of PCE ASSO DB
PCC decides to delete the second LSP. PCC sends PCRpt(R-FLAG=1,
PLSP-ID=200, LSP-ID=1).
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+---------------------------------------------------------------+
| ASSO | LSP |
+-----------------+---------------------------------------------+
| ASSO_PARAM=A | PLSP-ID=100, LSP-ID=1 |
+---------------------------------------------------------------+
Figure 12: Content of PCE ASSO DB
PCC decides to remove the first LSP from the Association, but not
delete the LSP itself. PCC sends PCRpt(R-FLAG=0, PLSP-ID=100, LSP-
ID=1, ASSO_PARAM=A, ASSO_R_FLAG=1). The PCE ASSO DB is now empty.
+---------------------------------------------------------------+
| ASSO | LSP |
+-----------------+---------------------------------------------+
| ASSO_PARAM=A | |
+---------------------------------------------------------------+
Figure 13: Content of PCE ASSO DB
4.2. Switch Association during MBB
Below, we give an example to illustrate how a Tunnel goes through MBB
and switches from Association A to Association B.
Each new LSP (identified by the LSP-ID) does not inherit the
Association membership of any previous LSPs within the same Tunnel.
This is so that a Tunnel can have two LSPs that are in different
Associations, this may be done when switching from one Association to
another.
PCC creates the first LSP. PCC sends PCRpt(R-FLAG=0, PLSP-ID=100,
LSP-ID=1, ASSO_PARAM=A, ASSO_R_FLAG=0).
+---------------------------------------------------------------+
| ASSO | LSP |
+-----------------+---------------------------------------------+
| ASSO_PARAM=A | PLSP-ID=100, LSP-ID=1 |
+---------------------------------------------------------------+
Figure 14: Content of PCE ASSO DB
PCC creates the MBB LSP in a different Association. PCC sends
PCRpt(R-FLAG=0, PLSP-ID=100, LSP-ID=2, ASSO_PARAM=B, ASSO_R_FLAG=0).
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+---------------------------------------------------------------+
| ASSO | LSP |
+-----------------+---------------------------------------------+
| ASSO_PARAM=A | PLSP-ID=100, LSP-ID=1 |
+---------------------------------------------------------------+
| ASSO_PARAM=B | PLSP-ID=100, LSP-ID=2 |
+---------------------------------------------------------------+
Figure 15: Content of PCE ASSO DB
PCC deletes the old LSP. PCC sends PCRpt(R-FLAG=1, PLSP-ID=100, LSP-
ID=1).
+---------------------------------------------------------------+
| ASSO | LSP |
+-----------------+---------------------------------------------+
| ASSO_PARAM=B | PLSP-ID=100, LSP-ID=2 |
+---------------------------------------------------------------+
Figure 16: Content of PCE ASSO DB
5. Computation Constraints
For any PCEP object that does not have an explicit removal flag, the
absence of that object indicates removal of the constraint specified
by that object. For example, suppose the first state-report contains
an LSPA object with some affinity constraints. Then if a subsequent
state-report does not contain an LSPA object, then this means that
the previously specified affinity constraints do not apply anymore.
Same applies to all PCEP objects, like METRIC, BANDWIDTH, etc., which
do not have an explicit flag for removal. This simply ensures that
it is possible to remove a constraint without using an explicit
removal flag.
6. Use of SR-RRO and SRv6-RRO objects
[RFC8231] defines a PCRpt message which contains <intended-path>
known as the ERO object and <actual-path> known as the RRO object.
[RFC8664] defines SR-ERO and SR-RRO sub-objects for SR-TE LSPs.
[I-D.ietf-pce-segment-routing-ipv6] further defines SRv6-ERO and
SRv6-RRO sub-objects for SRv6-TE paths.
In practice RRO data is the result of signalling via a protocol such
as RSVP-TE, which allows collection of per-hop information along the
path. The ERO and RRO values may be different as the path encoded in
the ERO may differ than the RRO such as during protection conditions
or if the ERO contains loose hops which are expanded upon. As
Segment Routing LSP does not perform any signalling, the values of an
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SR-ERO/SRv6-ERO and SR-RRO/SRv6-RRO (respectively) are in practice
the same, therefore some implementations have omitted the RRO when
reporting a SR-TE LSP while others continue to send both ERO and RRO
values.
The following applies to SR-TE only. If both ERO and RRO are present
for the same LSP, it SHOULD be interpreted as the RRO being the
actual path the LSP is taking but MAY interpret only the ERO as the
actual path. In the absence of RRO a PCE MUST interpret the ERO as
the actual path for the LSP. Until SR-TE introduces some form of
signaling similar to RSVP-TE, the use of RRO is discouraged for SR-TE
LSPs.
7. Security Considerations
None at this time.
8. IANA Considerations
None at this time.
9. Acknowledgement
The authors would like to thank Adrian Farrel for useful review
comments.
10. Normative References
[RFC2119] Bradner, S. and RFC Publisher, "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., Le Roux, JL., Ed., and RFC Publisher,
"Path Computation Element (PCE) Communication Protocol
(PCEP)", RFC 5440, DOI 10.17487/RFC5440, March 2009,
<https://www.rfc-editor.org/info/rfc5440>.
[RFC8174] Leiba, B. and RFC Publisher, "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., Varga, R., and RFC
Publisher, "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>.
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[RFC8664] Sivabalan, S., Filsfils, C., Tantsura, J., Henderickx, W.,
Hardwick, J., and RFC Publisher, "Path Computation Element
Communication Protocol (PCEP) Extensions for Segment
Routing", RFC 8664, DOI 10.17487/RFC8664, December 2019,
<https://www.rfc-editor.org/info/rfc8664>.
[RFC8697] Minei, I., Crabbe, E., Sivabalan, S., Ananthakrishnan, H.,
Dhody, D., Tanaka, Y., and RFC Publisher, "Path
Computation Element Communication Protocol (PCEP)
Extensions for Establishing Relationships between Sets of
Label Switched Paths (LSPs)", RFC 8697,
DOI 10.17487/RFC8697, January 2020,
<https://www.rfc-editor.org/info/rfc8697>.
[RFC3209] Awduche, D., Berger, L., Gan, D., Li, T., Srinivasan, V.,
Swallow, G., and RFC Publisher, "RSVP-TE: Extensions to
RSVP for LSP Tunnels", RFC 3209, DOI 10.17487/RFC3209,
December 2001, <https://www.rfc-editor.org/info/rfc3209>.
[I-D.ietf-pce-segment-routing-ipv6]
Li, C., Negi, M., Sivabalan, S., Koldychev, M.,
Kaladharan, P., and Y. Zhu, "Path Computation Element
Communication Protocol (PCEP) Extensions for Segment
Routing leveraging the IPv6 dataplane", draft-ietf-pce-
segment-routing-ipv6-15 (work in progress), October 2022,
<https://www.ietf.org/archive/id/draft-ietf-pce-segment-
routing-ipv6-15.txt>.
Appendix A. Contributors
Dhruv Dhody
Huawei Technologies
Divyashree Techno Park, Whitefield
Bangalore, Karnataka 560066
India
Email: dhruv.ietf@gmail.com
Andrew Stone
Nokia
Ottawa, Canada
Email: andrew.stone@nokia.com
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Samuel Sidor
Cisco Systems
Bratislava, Slovakia
Email: ssidor@cisco.com
Mahendra Singh Negi
RtBrick Inc
N-17L, 18th Cross Rd, HSR Layout
Bangalore, Karnataka 560102
India
Email: mahend.ietf@gmail.com
Authors' Addresses
Mike Koldychev
Cisco Systems, Inc.
2000 Innovation Drive
Kanata, Ontario K2K 3E8
Canada
Email: mkoldych@cisco.com
Siva Sivabalan
Ciena Corporation
385 Terry Fox Dr.
Kanata, Ontario K2K 0L1
Canada
Email: ssivabal@ciena.com
Shuping Peng
Huawei Technologies
Huawei Campus, No. 156 Beiqing Rd.
Beijing 100095
China
Email: pengshuping@huawei.com
Diego Achaval
Nokia
Email: diego.achaval@nokia.com
Koldychev, et al. Expires July 8, 2023 [Page 14]
Internet-Draft PCEP CLARIFICATION January 2023
Hari Kotni
Juniper Networks, Inc
Email: hkotni@juniper.net
Koldychev, et al. Expires July 8, 2023 [Page 15]
