Network Working Group C. Lin
Internet Draft New H3C Technologies
Intended status: Standards Track Y. Liu
Expires: April 23, 2026 China Mobile
October 20, 2025
PCEP extensions for energy consumption
draft-lin-pce-pcep-energy-efficiency-01
Abstract
[draft-liu-spring-sr-energy-consumption-00] describes the types of
energy consumption information, how to collect energy consumption
information, and the framework for path selection based on energy
consumption information. This document further details the process
of using the PCEP protocol for energy consumption based path
requests.
The Path Computation Element Communication Protocol (PCEP) provides
mechanisms that enable Path Computation Elements (PCEs) to perform
path computations in response to requests from Path Computation
Clients (PCCs).
This document describes the extension to PCEP for conveying link
energy consumption and node energy consumption, allowing path
computation based on these energy consumption information.
Status of this Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
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Task Force (IETF), its areas, and its working groups. Note that
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This Internet-Draft will expire on April 23, 2026.
Copyright Notice
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Table of Contents
1. Introduction...................................................3
1.1. Requirements Language.....................................4
2. Terminology....................................................4
3. PCEP Extensions................................................4
3.1. Extensions to METRIC Object...............................4
3.1.1. Path Node Maximum Energy Consumption.................5
3.1.2. Path Node Real-Time Energy Consumption...............6
3.1.3. Path Node Maximum Unit Energy Consumption............7
3.1.4. Path Node Real-Time Unit Energy Consumption..........7
3.1.5. Path Node Average Unit Energy Consumption............8
3.1.6. Path Interface Maximum Unit Energy Consumption.......9
3.1.7. Path Interface Real-Time Unit Energy Consumption....10
3.1.8. Path Interface Average Unit Energy Consumption......11
3.1.9. Non-Understanding / Non-Support of energy consumption11
3.1.10. Mode of Operation..................................12
3.1.10.1. Examples......................................13
3.1.11. Point-to-Multipoint (P2MP) Path Node Maximum Energy
Consumption................................................13
3.1.12. Point-to-Multipoint (P2MP) Path Node Real-Time Energy
Consumption................................................13
3.1.13. Point-to-Multipoint (P2MP) Path Node Maximum Unit
Energy Consumption.........................................14
3.1.14. Point-to-Multipoint (P2MP) Path Node Real-Time Unit
Energy Consumption.........................................14
3.1.15. Point-to-Multipoint (P2MP) Path Node Average Unit
Energy Consumption.........................................15
3.1.16. Point-to-Multipoint (P2MP) Path Interface Maximum Unit
Energy Consumption.........................................16
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3.1.17. Point-to-Multipoint (P2MP) Path Interface Real-Time
Unit Energy Consumption....................................16
3.1.18. Point-to-Multipoint (P2MP) Path Interface Average Unit
Energy Consumption.........................................17
3.1.19. Capability Advertisement...........................17
4. Stateful PCE and PCE Initiated LSPs...........................18
5. IANA Considerations...........................................18
5.1. METRIC Types.............................................18
5.2. ENERGY-CONSUMPTION-CAPABILITY............................20
6. Security Considerations.......................................20
7. References....................................................21
7.1. Normative References.....................................21
7.2. Informational References.................................21
Authors' Addresses...............................................21
1. Introduction
[draft-cx-green-green-metrics] describe multiple metrics that can be
used to measure the energy consumption.
[draft-liu-spring-sr-energy-efficiency-00] describes how energy-
consumption information is utilized in SR networks. It elaborates on
the use of energy consumption information for path computation in SR
networks.
The metrics for energy consumption include:
Node Maximum Energy Consumption: The power consumption of a node at
full load, measured in watts.
Node Real-Time Energy Consumption: The real-time power consumption
of a node, measured in watts.
Node Maximum Unit Energy Consumption: The power consumption of a
node at full load divided by traffic, measured in watts per gigabyte
(W/GB).
Node Real-Time Unit Energy Consumption: The real-time power
consumption of a node divided by real-time traffic, measured in
watts per gigabyte (W/GB).
Node Average Unit Energy Consumption: The change in power
consumption of a node over a measurement period divided by the
change in traffic, measured in watts per gigabyte (W/GB).
Interface Maximum Unit Energy Consumption: The power consumption of
an interface at full load divided by traffic, measured in watts per
gigabyte (W/GB).
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Interface Real-Time Unit Energy Consumption: The real-time power
consumption of an interface divided by real-time traffic, measured
in watts per gigabyte (W/GB).
Interface Average Unit Energy Consumption: The change in power
consumption of an interface over a measurement period divided by the
change in traffic, measured in watts per gigabyte (W/GB).
A Path Computation Client (PCC) can request a Path Computation
Element (PCE) to provide a path that meets end-to-end network
performance criteria. This document extends the Path Computation
Element Communication Protocol (PCEP) [RFC5440] to handle network
performance constraints based on energy consumption.
For PCC, there is no need to differentiate the types of specific
energy consumption information, as this is uniformly selected by PCE
based on actual energy consumption data.
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
See [RFC5540].
3. PCEP Extensions
This section defines PCEP extensions (see [RFC5440]) for energy
consumption.
3.1. Extensions to METRIC Object
The METRIC object is defined in Section 7.8 of [RFC5440], comprising
metric-value and metric-type (T field), and a flags field,
comprising a number of bit flags (B bit and P bit). (Section
3.1.1)This document defines the new type for the METRIC object.
o T=TBD1: Path Node Maximum Energy Consumption
o T=TBD2: Path Node Real-Time Energy Consumption
o T=TBD3: Path Node Maximum Unit Energy Consumption
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o T=TBD4: Path Node Real-Time Unit Energy Consumption
o T=TBD5: Path Node Average Unit Energy Consumption
o T=TBD6: Path Interface Maximum Unit Energy Consumption
o T=TBD7: Path Interface Real-Time Unit Energy Consumption
o T=TBD8: Path Interface Average Unit Energy Consumption
3.1.1. Path Node Maximum Energy Consumption
The Path Node Maximum Energy Consumption of the METRIC object in
PCEP represents the sum of the Node Maximum Energy Consumption of
all links along a point-to-point path.
Specifically, extending on the above-mentioned terminology:
o A Link Node Maximum Energy Consumption of link L is denoted
G(L).
o A Path Node Maximum Energy Consumption for the P2P path P =
Sum {G(Lpi), (i=1...K)}.
A PCC MAY use the Path Node Maximum Energy Consumption in a Path
Computation Request (PCReq) message to request a path meeting the
end-to-end Node Maximum Energy Consumption requirement. In this
case, the B bit MUST be set to suggest a bound (a maximum) for the
Path energy consumption that must not be exceeded for the PCC to
consider the computed path as acceptable. The Path Node Maximum
Energy Consumption must be less than or equal to the value specified
in the metric-value field.
A PCC can also use this metric to ask PCE to optimize the path Node
Maximum Energy Consumption during path computation. In this case,
the B bit MUST be cleared.
A PCE MAY use the Path Node Maximum Energy Consumption in a Path
Computation Reply (PCRep) message along with a NO-PATH object in the
case where the PCE cannot compute a path meeting this constraint. A
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PCE can also use this metric to send the computed Path Node Maximum
Energy Consumption to the PCC.
energy consumption value range (0 - 4,294,967,295), in a 32-bit
field.
3.1.2. Path Node Real-Time Energy Consumption
The Path Node Real-Time Energy Consumption of the METRIC object in
PCEP represents the sum of the Node Real-Time Energy Consumption of
all links along a point-to-point path.
Specifically, extending on the above-mentioned terminology:
o A Link Node Real-Time Energy Consumption of link L is denoted
G(L).
o A Path Node Real-Time Energy Consumption for the P2P path P =
Sum {G(Lpi), (i=1...K)}.
A PCC MAY use the Path Node Real-Time Energy Consumption in a Path
Computation Request (PCReq) message to request a path meeting the
end-to-end Node Real-Time Energy Consumption requirement. In this
case, the B bit MUST be set to suggest a bound (a maximum) for the
Path Node Real-Time Energy Consumption that must not be exceeded for
the PCC to consider the computed path as acceptable. The Node Real-
Time Energy Consumption must be less than or equal to the value
specified in the metric-value field.
A PCC can also use this metric to ask PCE to optimize the path Node
Real-Time Energy Consumption during path computation. In this case,
the B bit MUST be cleared.
A PCE MAY use the Path Node Real-Time Energy Consumption in a Path
Computation Reply (PCRep) message along with a NO-PATH object in the
case where the PCE cannot compute a path meeting this constraint. A
PCE can also use this metric to send the computed Path Node Real-
Time Energy Consumption to the PCC.
energy consumption value range (0 - 4,294,967,295), in a 32-bit
field.
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3.1.3. Path Node Maximum Unit Energy Consumption
The Path Node Maximum Unit Energy Consumption of the METRIC object
in PCEP represents the sum of the Node Maximum Unit Energy
Consumption of all links along a point-to-point path.
Specifically, extending on the above-mentioned terminology:
o A Link Node Maximum Unit Energy Consumption of link L is
denoted G(L).
o A Path Node Maximum Unit Energy Consumption for the P2P path P
= Sum {G(Lpi), (i=1...K)}.
A PCC MAY use the Path Node Maximum Unit Energy Consumption in a
Path Computation Request (PCReq) message to request a path meeting
the end-to-end Node Maximum Unit Energy Consumption requirement. In
this case, the B bit MUST be set to suggest a bound (a maximum) for
the Path Node Maximum Unit Energy Consumption that must not be
exceeded for the PCC to consider the computed path as acceptable.
The Node Maximum Unit Energy Consumption must be less than or equal
to the value specified in the metric-value field.
A PCC can also use this metric to ask PCE to optimize the path Node
Maximum Unit Energy Consumption during path computation. In this
case, the B bit MUST be cleared.
A PCE MAY use the Path Node Maximum Unit Energy Consumption in a
Path Computation Reply (PCRep) message along with a NO-PATH object
in the case where the PCE cannot compute a path meeting this
constraint. A PCE can also use this metric to send the computed
Path Node Maximum Unit Energy Consumption to the PCC.
energy consumption value range (0 - 4,294,967,295), in a 32-bit
field.
3.1.4. Path Node Real-Time Unit Energy Consumption
The Node Real-Time Unit Energy Consumption of the METRIC object in
PCEP represents the sum of the Node Real-Time Unit Energy
Consumption of all links along a point-to-point path.
Specifically, extending on the above-mentioned terminology:
o A Link Node Real-Time Unit Energy Consumption of link L is
denoted G(L).
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o A Path Node Real-Time Unit Energy Consumption for the P2P path
P = Sum {G(Lpi), (i=1...K)}.
A PCC MAY use the Path Node Real-Time Unit Energy Consumption in a
Path Computation Request (PCReq) message to request a path meeting
the end-to-end Node Real-Time Unit Energy Consumption requirement.
In this case, the B bit MUST be set to suggest a bound (a maximum)
for the Path Node Real-Time Unit Energy Consumption that must not be
exceeded for the PCC to consider the computed path as acceptable.
The Node Real-Time Unit Energy Consumption must be less than or
equal to the value specified in the metric-value field.
A PCC can also use this metric to ask PCE to optimize the path Node
Real-Time Unit Energy Consumption during path computation. In this
case, the B bit MUST be cleared.
A PCE MAY use the Path Node Real-Time Unit Energy Consumption in a
Path Computation Reply (PCRep) message along with a NO-PATH object
in the case where the PCE cannot compute a path meeting this
constraint. A PCE can also use this metric to send the computed
Path Node Real-Time Unit Energy Consumption to the PCC.
energy consumption value range (0 - 4,294,967,295), in a 32-bit
field.
3.1.5. Path Node Average Unit Energy Consumption
The Path Node Average Unit Energy Consumption of the METRIC object
in PCEP represents the sum of the Node Average Unit Energy
Consumption of all links along a point-to-point path.
Specifically, extending on the above-mentioned terminology:
o A Link Node Average Unit Energy Consumption of link L is
denoted G(L).
o A Path Node Average Unit Energy Consumption for the P2P path P
= Sum {G(Lpi), (i=1...K)}.
A PCC MAY use the Path Node Average Unit Energy Consumption in a
Path Computation Request (PCReq) message to request a path meeting
the end-to-end Node Average Unit Energy Consumption requirement. In
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this case, the B bit MUST be set to suggest a bound (a maximum) for
the Path Node Average Unit Energy Consumption that must not be
exceeded for the PCC to consider the computed path as acceptable.
The Node Average Unit Energy Consumption must be less than or equal
to the value specified in the metric-value field.
A PCC can also use this metric to ask PCE to optimize the path Node
Node Average Unit Energy Consumption during path computation. In
this case, the B bit MUST be cleared.
A PCE MAY use the Path Node Average Unit Energy Consumption in a
Path Computation Reply (PCRep) message along with a NO-PATH object
in the case where the PCE cannot compute a path meeting this
constraint. A PCE can also use this metric to send the computed
Path Node Node Average Unit Energy Consumption to the PCC.
energy consumption value range (0 - 4,294,967,295), in a 32-bit
field.
3.1.6. Path Interface Maximum Unit Energy Consumption
The Path Interface Maximum Unit Energy Consumption of the METRIC
object in PCEP represents the sum of the Interface Maximum Unit
Energy Consumption of all links along a point-to-point path.
Specifically, extending on the above-mentioned terminology:
o A Link Interface Maximum Unit Energy Consumption of link L is
denoted G(L).
o A Path Interface Maximum Unit Energy Consumption for the P2P
path P = Sum {G(Lpi), (i=1...K)}.
A PCC MAY use the Path Interface Maximum Unit Energy Consumption in
a Path Computation Request (PCReq) message to request a path meeting
the end-to-end Interface Maximum Unit Energy Consumption
requirement. In this case, the B bit MUST be set to suggest a bound
(a maximum) for the Path Interface Maximum Unit Energy Consumption
that must not be exceeded for the PCC to consider the computed path
as acceptable. The Interface Maximum Unit Energy Consumption must be
less than or equal to the value specified in the metric-value field.
A PCC can also use this metric to ask PCE to optimize the path
Interface Maximum Unit Energy Consumption during path computation.
In this case, the B bit MUST be cleared.
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A PCE MAY use the Path Interface Maximum Unit Energy Consumption in
a Path Computation Reply (PCRep) message along with a NO-PATH object
in the case where the PCE cannot compute a path meeting this
constraint. A PCE can also use this metric to send the computed
Path Interface Maximum Unit Energy Consumption to the PCC.
energy consumption value range (0 - 4,294,967,295), in a 32-bit
field.
3.1.7. Path Interface Real-Time Unit Energy Consumption
The Path Interface Real-Time Unit Energy Consumption of the METRIC
object in PCEP represents the sum of the Interface Real-Time Unit
Energy Consumption of all links along a point-to-point path.
Specifically, extending on the above-mentioned terminology:
o A Link Interface Real-Time Unit Energy Consumption of link L
is denoted G(L).
o A Path Interface Real-Time Unit Energy Consumption for the P2P
path P = Sum {G(Lpi), (i=1...K)}.
A PCC MAY use the Path Interface Real-Time Unit Energy Consumption
in a Path Computation Request (PCReq) message to request a path
meeting the end-to-end Interface Real-Time Unit Energy Consumption
requirement. In this case, the B bit MUST be set to suggest a bound
(a maximum) for the Path Interface Real-Time Unit Energy Consumption
that must not be exceeded for the PCC to consider the computed path
as acceptable. The Interface Real-Time Unit Energy Consumption must
be less than or equal to the value specified in the metric-value
field.
A PCC can also use this metric to ask PCE to optimize the path
Interface Real-Time Unit Energy Consumption during path computation.
In this case, the B bit MUST be cleared.
A PCE MAY use the Path Interface Real-Time Unit Energy Consumption
in a Path Computation Reply (PCRep) message along with a NO-PATH
object in the case where the PCE cannot compute a path meeting this
constraint. A PCE can also use this metric to send the computed
Path Interface Real-Time Unit Energy Consumption to the PCC.
energy consumption value range (0 - 4,294,967,295), in a 32-bit
field.
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3.1.8. Path Interface Average Unit Energy Consumption
The Path Interface Average Unit Energy Consumption of the METRIC
object in PCEP represents the sum of the Interface Average Unit
Energy Consumption of all links along a point-to-point path.
Specifically, extending on the above-mentioned terminology:
o A Link Interface Average Unit Energy Consumption of link L is
denoted G(L).
o A Path Interface Average Unit Energy Consumption for the P2P
path P = Sum {G(Lpi), (i=1...K)}.
A PCC MAY use the Path Interface Average Unit Energy Consumption in
a Path Computation Request (PCReq) message to request a path meeting
the end-to-end Interface Average Unit Energy Consumption
requirement. In this case, the B bit MUST be set to suggest a bound
(a maximum) for the Path Interface Average Unit Energy Consumption
that must not be exceeded for the PCC to consider the computed path
as acceptable. The Interface Average Unit Energy Consumption must be
less than or equal to the value specified in the metric-value field.
A PCC can also use this metric to ask PCE to optimize the path
Interface Average Unit Energy Consumption during path computation.
In this case, the B bit MUST be cleared.
A PCE MAY use the Path Interface Average Unit Energy Consumption in
a Path Computation Reply (PCRep) message along with a NO-PATH object
in the case where the PCE cannot compute a path meeting this
constraint. A PCE can also use this metric to send the computed
Path Interface Average Unit Energy Consumption to the PCC.
energy consumption value range (0 - 4,294,967,295), in a 32-bit
field.
3.1.9. Non-Understanding / Non-Support of energy consumption
If a PCE receives a PCReq message containing a METRIC object with a
type defined in this document, and the PCE does not understand or
support that metric type, and the P bit is clear in the METRIC
object header, then the PCE SHOULD simply ignore the METRIC object
as per the processing specified in [RFC5440].
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If the PCE understands but does not support the new METRIC type, and
the P bit is set in the METRIC object header, then the PCE MUST send
a PCErr message containing a PCEP-ERROR Object with Error-Type = 4
(Not supported object) with Error-value = 5 (Unsupported network
performance constraint). The path computation request MUST then be
canceled.
If the PCE does not understand the new METRIC type, and the P bit is
set in the METRIC object header, then the PCE MUST send a PCEP Error
(PCErr) message containing a PCEP-ERROR Object with Error-Type = 4
(Not supported object) and Error-value = 4 (Unsupported parameter)
[RFC5440][RFC5441].
If the PCE understands the new METRIC type, but the local policy has
been configured on the PCE to not allow network energy consumption
constraint, and the P bit is set in the METRIC object header, then
the PCE MUST send a PCErr message containing a PCEP-ERROR Object
with Error-Type = 5 (Policy violation) with Error-value = 8 (Not
allowed network performance constraint). The path computation
request MUST then be canceled.
3.1.10. Mode of Operation
As explained in [RFC5440], the METRIC object is optional and can be
used for several purposes. In a PCReq message, a PCC MAY insert one
or more METRIC objects:
o To indicate the metric that MUST be optimized by the path
computation algorithm (path Node Maximum Energy Consumption).
o To indicate a bound on the METRIC (path Node Maximum Energy
Consumption) that MUST NOT be exceeded for the path to be considered
as acceptable by the PCC.
In a PCRep message, the PCE MAY insert the METRIC object with an
Explicit Route Object (ERO) so as to provide the METRIC (path Node
Maximum Energy Consumption) for the computed path. The PCE MAY also
insert the METRIC object with a NO-PATH object to indicate that the
metric constraint could not be satisfied.
The path computation algorithmic aspects used by the PCE to optimize
a path with respect to a specific metric are outside the scope of
this document.
All the rules of processing the METRIC object as explained in
[RFC5440] are applicable to the new metric types as well.
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3.1.10.1. Examples
If a PCC sends a path computation request to a PCE where the metric
to optimize is the path Node Maximum Energy Consumption and the path
Node Maximum Energy Consumption must not exceed the value of M, then
a METRIC object is inserted in the PCReq message:
o METRIC object with B=1, T=(TBD1), metric-value=M
As per [RFC5440], if a path satisfying the set of constraints can be
found by the PCE and there is no policy that prevents the return of
the computed metric, then the PCE inserts one METRIC object with
B=0, T=Node Maximum Energy Consumption(TBD1), metric-value= computed
path Node Maximum Energy Consumption Metric.
3.1.11. Point-to-Multipoint (P2MP) Path Node Maximum Energy Consumption
The P2MP Path Node Maximum Energy Consumption type of the METRIC
object in PCEP encodes the Path Node Maximum Energy Consumption for
the destination that observes the worst Node Maximum Energy
Consumption among all destinations of the P2MP tree. Specifically,
extending on the above-mentioned terminology:
o A P2MP tree T comprises a set of M destinations {Dest_j,
(j=1...M)}.
o The P2P Path Node Maximum Energy Consumption of the path to
destination Dest_j is denoted by PDM(Dest_j).
o The P2MP Path Node Maximum Energy Consumption for the P2MP
tree T = Maximum
{PDM(Dest_j), (j=1...M)}.
The value for the P2MP Path Node Maximum Energy Consumption type (T)
= (TBD9).
3.1.12. Point-to-Multipoint (P2MP) Path Node Real-Time Energy
Consumption
The P2MP Path Node Real-Time Energy Consumption Consumption type of
the METRIC object in PCEP encodes the Path Node Real-Time Energy
Consumption for the destination that observes the worst Node Real-
Time Energy Consumption among all destinations of the P2MP tree.
Specifically, extending on the above-mentioned terminology:
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o A P2MP tree T comprises a set of M destinations {Dest_j,
(j=1...M)}.
o The P2P Path Node Real-Time Energy Consumption of the path to
destination Dest_j is denoted by PDM(Dest_j).
o The P2MP Path Node Real-Time Energy Consumption for the P2MP
tree T = Maximum
{PDM(Dest_j), (j=1...M)}.
The value for the P2MP Path Node Real-Time Energy Consumption type
(T) = (TBD10).
3.1.13. Point-to-Multipoint (P2MP) Path Node Maximum Unit Energy
Consumption
The P2MP Path Node Maximum Unit Energy Consumption type of the
METRIC object in PCEP encodes the Path Node Maximum Unit Energy
Consumption for the destination that observes the worst Node Maximum
Unit Energy Consumption among all destinations of the P2MP tree.
Specifically, extending on the above-mentioned terminology:
o A P2MP tree T comprises a set of M destinations {Dest_j,
(j=1...M)}.
o The P2P Path Node Maximum Unit Energy Consumption of the path
to destination Dest_j is denoted by PDM(Dest_j).
o The P2MP Path Node Maximum Unit Energy Consumption for the
P2MP tree T = Maximum
{PDM(Dest_j), (j=1...M)}.
The value for the P2MP Path Node Maximum Unit Energy Consumption
type (T) = (TBD11).
3.1.14. Point-to-Multipoint (P2MP) Path Node Real-Time Unit Energy
Consumption
The P2MP Path Node Real-Time Unit Energy Consumption type of the
METRIC object in PCEP encodes the Path Node Real-Time Unit Energy
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Consumption for the destination that observes the worst Node Real-
Time Unit Energy Consumption among all destinations of the P2MP
tree. Specifically, extending on the above-mentioned terminology:
o A P2MP tree T comprises a set of M destinations {Dest_j,
(j=1...M)}.
o The P2P Path Node Real-Time Unit Energy Consumption of the
path to destination Dest_j is denoted by PDM(Dest_j).
o The P2MP Path Node Real-Time Unit Energy Consumption for the
P2MP tree T = Maximum
{PDM(Dest_j), (j=1...M)}.
The value for the P2MP Path Node Real-Time Unit Energy Consumption
type (T) = (TBD12).
3.1.15. Point-to-Multipoint (P2MP) Path Node Average Unit Energy
Consumption
The P2MP Path Node Average Unit Energy Consumption type of the
METRIC object in PCEP encodes the Path Node Average Unit Energy
Consumption for the destination that observes the worst Node Average
Unit Energy Consumption among all destinations of the P2MP tree.
Specifically, extending on the above-mentioned terminology:
o A P2MP tree T comprises a set of M destinations {Dest_j,
(j=1...M)}.
o The P2P Path Node Average Unit Energy Consumption of the path
to destination Dest_j is denoted by PDM(Dest_j).
o The P2MP Path Node Average Unit Energy Consumption for the
P2MP tree T = Maximum
{PDM(Dest_j), (j=1...M)}.
The value for the P2MP Path Node Average Unit Energy Consumption
type (T) = (TBD13).
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3.1.16. Point-to-Multipoint (P2MP) Path Interface Maximum Unit Energy
Consumption
The P2MP Path Interface Maximum Unit Energy Consumption type of the
METRIC object in PCEP encodes the Path Interface Maximum Unit Energy
Consumption for the destination that observes the worst Interface
Maximum Unit Energy Consumption among all destinations of the P2MP
tree. Specifically, extending on the above-mentioned terminology:
o A P2MP tree T comprises a set of M destinations {Dest_j,
(j=1...M)}.
o The P2P Path Interface Maximum Unit Energy Consumption of the
path to destination Dest_j is denoted by PDM(Dest_j).
o The P2MP Path Interface Maximum Unit Energy Consumption for
the P2MP tree T = Maximum
{PDM(Dest_j), (j=1...M)}.
The value for the P2MP Path Interface Maximum Unit Energy
Consumption type (T) = (TBD14).
3.1.17. Point-to-Multipoint (P2MP) Path Interface Real-Time Unit Energy
Consumption
The P2MP Path Interface Real-Time Unit Energy Consumption type of
the METRIC object in PCEP encodes the Path Interface Real-Time Unit
Energy Consumption for the destination that observes the worst
Interface Real-Time Unit Energy Consumption among all destinations
of the P2MP tree. Specifically, extending on the above-mentioned
terminology:
o A P2MP tree T comprises a set of M destinations {Dest_j,
(j=1...M)}.
o The P2P Path Interface Real-Time Unit Energy Consumption of
the path to destination Dest_j is denoted by PDM(Dest_j).
o The P2MP Path Interface Real-Time Unit Energy Consumption for
the P2MP tree T = Maximum
{PDM(Dest_j), (j=1...M)}.
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The value for the P2MP Path Interface Real-Time Unit Energy
Consumption type (T) = (TBD15).
3.1.18. Point-to-Multipoint (P2MP) Path Interface Average Unit Energy
Consumption
The P2MP Path Interface Average Unit Energy Consumption type of the
METRIC object in PCEP encodes the Path Interface Average Unit Energy
Consumption for the destination that observes the worst Interface
Average Unit Energy Consumption among all destinations of the P2MP
tree. Specifically, extending on the above-mentioned terminology:
o A P2MP tree T comprises a set of M destinations {Dest_j,
(j=1...M)}.
o The P2P Path Interface Average Unit Energy Consumption of the
path to destination Dest_j is denoted by PDM(Dest_j).
o The P2MP Path Interface Average Unit Energy Consumption for
the P2MP tree T = Maximum
{PDM(Dest_j), (j=1...M)}.
The value for the P2MP Path Interface Average Unit Energy
Consumption type (T) = (TBD16).
3.1.19. Capability Advertisement
During the PCEP initialization phase, PCEP speakers (PCE or PCC)
announce their support for the energy consumption feature. A PCEP
speaker includes the ENERGY-CONSUMPTION-CAPABILITY TLV in the OPEN
object to indicate its support for PCEP GMetric. The presence of the
ENERGY-CONSUMPTION-CAPABILITY TLV in the OPEN object signifies
support for the energy consumption feature as described in this
document.
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=TBD17 | Length=4 |
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Flag |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure: ENERGY-CONSUMPTION-CAPABILITY TLV Format
4. Stateful PCE and PCE Initiated LSPs
[RFC8231] specifies a set of extensions to PCEP to enable stateful
control of MPLS-TE and GMPLS LSPs via PCEP and the maintaining of
these LSPs at the stateful PCE. It further distinguishes between an
active and a passive stateful PCE. A passive stateful PCE uses LSP
state information learned from PCCs to optimize path computations
but does not actively update LSP state. In contrast, an active
stateful PCE utilizes the LSP delegation mechanism to update LSP
parameters in those PCCs that delegated control over their LSPs to
the PCE.
[PCE-INITIATED] describes the setup, maintenance, and teardown of
PCE-initiated LSPs under the stateful PCE model. The document
defines the PCInitiate message that is used by a PCE to request a
PCC to set up a new LSP.
The new metric type and objective functions defined in this document
can also be used with the stateful PCE extensions. The format of
PCEP messages described in [RFC8231] and [PCE-INITIATED] uses
<intended-attribute-list> and <attribute-list>, respectively, (where
the <intended-attribute-list> is the attribute-list defined in
Section 6.5 of [RFC5440] and extended in Section 5.2 of this
document) for the purpose of including the service-aware parameters.
The stateful PCE implementation MAY use the extension of PCReq and
PCRep messages as defined in Sections 5.1 and 5.2 to enable the use
of service-aware parameters during passive stateful operations.
5. IANA Considerations
5.1. METRIC Types
IANA maintains the "Path Computation Element Protocol (PCEP)
Numbers" registry at <http://www.iana.org/assignments/pcep>. Within
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this registry, IANA maintains a subregistry for "METRIC Object T
Field".
The new metric types are defined in this document for the METRIC
object (specified in [RFC5440]).
Value Description Reference
----------------------------------------------------------
TBD1 Path Node Maximum This Document
Energy Consumption
TBD2 Path Node Real-Time This Document
Energy Consumption
TBD3 Path Node Maximum Unit This Document
Energy Consumption
TBD4 Path Node Real-Time Unit This Document
Energy Consumption
TBD5 Path Node Average Unit This Document
Energy Consumption
TBD6 Path Interface Maximum Unit This Document
Energy Consumption
TBD7 Path Interface Real-Time Unit This Document
Energy Consumption
TBD8 Path Interface Average Unit This Document
Energy Consumption
TBD9 P2MP Path Node Maximum This Document
Energy Consumption
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TBD10 P2MP Path Node Real-Time This Document
Energy Consumption
TBD11 P2MP Path Node Maximum Unit This Document
Energy Consumption
TBD12 P2MP Path Node Real-Time Unit This Document
Energy Consumption
TBD13 P2MP Path Node Average Unit This Document
Energy Consumption
TBD14 P2MP Path Interface Maximum This Document
Unit Energy Consumption
TBD15 P2MP Path Interface Real-Time This Document
Unit Energy Consumption
TBD16 P2MP Path Interface Average This Document
Unit Energy Consumption
5.2. ENERGY-CONSUMPTION-CAPABILITY
| Value | Description
+=============+===================
| TBD17 | ENERGY-CONSUMPTION-CAPABILITY
6. Security Considerations
TBD.
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7. References
7.1. Normative References
[RFC8233] D. Dhody, Q. Wu, Huawei, V. Manral, Nano Sec Co, Z. Ali,
Cisco Systems, K. Kumaki, KDDI Corporation, "Extensions to
the Path Computation Element Communication Protocol (PCEP)
to Compute Service-Aware Label Switched Paths (LSPs)", RFC
8233, DOI 10.17487/RFC8233, September 2017,
<https://www.rfc-editor.org/info/rfc8233>.
[RFC5440] JP. Vasseur, Ed., Cisco Systems, JL. Le Roux, Ed., France
Telecom, "Path Computation Element (PCE) Communication
Protocol (PCEP)", RFC 8233, DOI 10.17487/RFC5440, March
2009, <https://www.rfc-editor.org/info/rfc5440>.
[draft-liu-spring-sr-energy-efficiency-00] lin, New H3C
Technologies, "Computing Energy Consumption Path in
Segment Routing Networks", draft-liu-spring-sr-energy-
efficiency -00, DOI 10.17487/draft-liu-spring-sr-for-
green-metric-00, Febauary 2025, <https://www.rfc-
editor.org/info/DOI 10.17487/draft-liu-spring-sr-energy-
consumption-00>.
7.2. Informational References
TBD
Authors' Addresses
Changwang Lin
New H3C Technologies
China
Email: linchangwang.04414@h3c.com
Yisong Liu
China Mobile
China
Email: liuyisong@chinamobile.com
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