Internet DRAFT - draft-dhody-pce-pcep-service-aware
draft-dhody-pce-pcep-service-aware
PCE Working Group D. Dhody
Internet-Draft Huawei Technologies India Pvt
Intended status: Standards Track Ltd
Expires: August 24, 2013 V. Manral
Hewlett-Packard Corp.
Z. Ali
G. Swallow
Cisco Systems
K. Kumaki
KDDI Corporation
February 25, 2013
Extensions to the Path Computation Element Communication Protocol (PCEP)
to compute service aware Label Switched Path (LSP).
draft-dhody-pce-pcep-service-aware-05
Abstract
In certain networks like financial information network (stock/
commodity trading) and enterprises using cloud based applications,
Latency (delay), Latency-Variation (jitter) and Packet loss is
becoming a key requirement for path computation along with other
constraints and metrics. Latency, Latency-Variation and Packet Loss
is associated with the Service Level Agreement (SLA) between
customers and service providers.
[MPLS-DELAY-FWK] describes MPLS architecture to allow Latency
(delay), Latency-Variation (jitter) and Packet loss as properties.
[OSPF-TE-EXPRESS] and [ISIS-TE-EXPRESS] describes mechanisms with
which network performance information is distributed via OSPF and
ISIS respectively. This document describes the extension to PCEP to
carry Latency, Latency-Variation and Loss as constraints for end to
end path computation.
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
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material or to cite them other than as "work in progress."
This Internet-Draft will expire on June 4, 2013.
Copyright Notice
Copyright (c) 2012 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
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described in the Simplified BSD License.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4
1.1. Requirements Language . . . . . . . . . . . . . . . . . . 4
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4
3. PCEP Requirements . . . . . . . . . . . . . . . . . . . . . . 5
4. PCEP extensions . . . . . . . . . . . . . . . . . . . . . . . 5
4.1. Latency (Delay) Metric . . . . . . . . . . . . . . . . . . 6
4.1.1. Latency (Delay) Metric Value . . . . . . . . . . . . . 6
4.2. Latency Variation (Jitter) Metric . . . . . . . . . . . . 7
4.2.1. Latency Variation (Jitter) Metric Value . . . . . . . 7
4.3. Packet Loss Metric . . . . . . . . . . . . . . . . . . . . 8
4.3.1. Packet Loss Metric Value . . . . . . . . . . . . . . . 9
4.4. Non-Understanding / Non-Support of Service Aware Path
Computation . . . . . . . . . . . . . . . . . . . . . . . 9
4.5. Mode of Operation . . . . . . . . . . . . . . . . . . . . 9
4.5.1. Examples . . . . . . . . . . . . . . . . . . . . . . . 10
5. Relationship with Objective function . . . . . . . . . . . . . 11
6. Protocol Consideration . . . . . . . . . . . . . . . . . . . . 11
6.1. Inter domain Consideration . . . . . . . . . . . . . . . . 11
6.1.1. Inter-AS Link . . . . . . . . . . . . . . . . . . . . 12
6.1.2. Inter-Layer Consideration . . . . . . . . . . . . . . 12
6.2. Reoptimization Consideration . . . . . . . . . . . . . . . 12
6.3. Point-to-Multipoint (P2MP) . . . . . . . . . . . . . . . . 12
6.3.1. P2MP Latency Metric . . . . . . . . . . . . . . . . . 12
6.3.2. P2MP Latency Variation Metric . . . . . . . . . . . . 13
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 13
8. Security Considerations . . . . . . . . . . . . . . . . . . . 13
9. Manageability Considerations . . . . . . . . . . . . . . . . . 14
9.1. Control of Function and Policy . . . . . . . . . . . . . . 14
9.2. Information and Data Models . . . . . . . . . . . . . . . 14
9.3. Liveness Detection and Monitoring . . . . . . . . . . . . 14
9.4. Verify Correct Operations . . . . . . . . . . . . . . . . 14
9.5. Requirements On Other Protocols . . . . . . . . . . . . . 14
9.6. Impact On Network Operations . . . . . . . . . . . . . . . 14
10. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 14
11. References . . . . . . . . . . . . . . . . . . . . . . . . . . 15
11.1. Normative References . . . . . . . . . . . . . . . . . . . 15
11.2. Informative References . . . . . . . . . . . . . . . . . . 15
Appendix A. Contributor Addresses . . . . . . . . . . . . . . . . 16
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1. Introduction
Real time Network Performance is becoming a critical in the path
computation in some networks. There exist mechanism described in
[RFC6374] to measure latency, latency-Variation and packet loss after
the LSP has been established, which is inefficient. It is important
that latency, latency-variation and packet loss are considered during
path selection process, even before the LSP is setup.
TED is populated with network performance information like link
latency, latency variation and packet loss through [OSPF-TE-EXPRESS]
or [ISIS-TE-EXPRESS]. Path Computation Client (PCC) can request Path
Computation Element (PCE) to provide a path meeting end to end
network performance criteria. This document extends Path Computation
Element Communication Protocol (PCEP) [RFC5440] to handle network
performance constraint.
PCE MAY use mechanism described in [MPLS-TE-EXPRESS-PATH] on how to
use the link latency, latency variation and packet loss information
for end to end path selection.
1.1. 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].
2. Terminology
The following terminology is used in this document.
IGP: Interior Gateway Protocol. Either of the two routing
protocols, Open Shortest Path First (OSPF) or Intermediate System
to Intermediate System (IS-IS).
IS-IS: Intermediate System to Intermediate System.
OSPF: Open Shortest Path First.
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.
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TE: Traffic Engineering.
3. PCEP Requirements
End-to-end service optimization based on latency, latency-variation
and packet loss is a key requirement for service provider. Following
key requirements associated with latency, latency-variation and loss
are identified for PCEP:
1. Path Computation Element (PCE) supporting this draft MUST have
the capability to compute end-to-end path with latency, latency-
variation and packet loss constraints. It MUST also support the
combination of network performance constraint (latency, latency-
variation, loss...) with existing constraints (cost, hop-
limit...)
2. Path Computation Client (PCC) MUST be able to request for network
performance constraint in path request message as the key
constraint to be optimized or to suggest boundary condition that
should not be crossed.
3. PCEs are not required to support service aware path computation.
Therefore, it MUST be possible for a PCE to reject a Path
Computation Request message with a reason code that indicates no
support for service-aware path computation.
4. PCEP SHOULD provide a means to return end to end network
performance information of the computed path in the reply
message.
5. PCEP SHOULD provide mechanism to compute multi-domain (e.g.,
Inter-AS, Inter-Area or Multi-Layer) service aware paths.
It is assumed that such constraints are only meaningful if used
consistently: for instance, if the delay of a computed path segment
is exchanged between two PCEs residing in different domains,
consistent ways of defining the delay must be used.
4. PCEP extensions
This section defines PCEP extensions (see [RFC5440]) for requirements
outlined in Section 3. The proposed solution is used to support
network performance and service aware path computation.
This document defines the following optional types for the METRIC
object defined in [RFC5440].
For explanation of these metrics, the following terminology is used
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and expanded along the way.
- A network comprises of a set of N links {Li, (i=1...N)}.
- A path P of a P2P LSP is a list of K links {Lpi,(i=1...K)}.
4.1. Latency (Delay) Metric
Link delay metric is defined in [OSPF-TE-EXPRESS] and [ISIS-TE-
EXPRESS]. P2P latency metric type of METRIC object in PCEP encodes
the sum of the link delay metric of all links along a P2P Path.
Specifically, extending on the above mentioned terminology:
- A Link delay metric of link L is denoted D(L).
- A P2P latency metric for the Path P = Sum {D(Lpi), (i=1...K)}.
* T=13(IANA): Latency metric
PCC MAY use this latency metric In PCReq to request a path meeting
the end to end latency requirement. In this case B bit MUST be set
to suggest a bound (a maximum) for the path latency metric that must
not be exceeded for the PCC to consider the computed path as
acceptable. The path metric must be less than or equal to the value
specified in the metric-value field.
PCC MAY also use this metric to ask PCE to optimize delay during path
computation, in this case B flag will be cleared.
PCE MAY use this latency metric In PCRep along with NO-PATH object
incase PCE cannot compute a path meeting this constraint. PCE MAY
also use this metric to reply the computed end to end latency metric
to PCC.
4.1.1. Latency (Delay) Metric Value
[OSPF-TE-EXPRESS] and [ISIS-TE-EXPRESS] defines "Unidirectional Link
Delay Sub-TLV" in a 24-bit field. [RFC5440] defines the METRIC
object with 32-bit metric value. Consequently, encoding for Latency
(Delay) Metric Value is defined as follows:
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Reserved | Latency (Delay) Metric |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Reserved (8 bits): Reserved field. This field MUST be set to zero on
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transmission and MUST be ignored on receipt.
Latency (Delay) Metric (24 bits): Represents the end to end Latency
(delay) quantified in units of microseconds and MUST be encoded as
integer value. With the maximum value 16,777,215 representing
16.777215 sec.
4.2. Latency Variation (Jitter) Metric
Link delay variation metric is defined in [OSPF-TE-EXPRESS] and
[ISIS-TE-EXPRESS]. P2P latency variation metric type of METRIC
object in PCEP encodes a function of the link delay variation metric
of all links along a P2P Path. Specifically, extending on the above
mentioned terminology:
- A Latency variation of link L is denoted DV(L).
- A P2P latency variation metric for the Path P = function {DV(Lpi),
(i=1...K)}.
Specification of the "Function" used to drive latency variation
metric of a path from latency variation metrics of individual links
along the path is beyond the scope of this document.
* T=14(IANA): Latency Variation metric
PCC MAY use this latency variation metric In PCReq to request a path
meeting the end to end latency variation requirement. In this case B
bit MUST be set to suggest a bound (a maximum) for the path latency
variation metric that must not be exceeded for the PCC to consider
the computed path as acceptable. The path metric must be less than
or equal to the value specified in the metric-value field.
PCC MAY also use this metric to ask PCE to optimize jitter during
path computation, in this case B flag will be cleared.
PCE MAY use this latency variation metric In PCRep along with NO-PATH
object incase PCE cannot compute a path meeting this constraint. PCE
MAY also use this metric to reply the computed end to end latency
variation metric to PCC.
4.2.1. Latency Variation (Jitter) Metric Value
[OSPF-TE-EXPRESS] and [ISIS-TE-EXPRESS] defines "Unidirectional Delay
Variation Sub-TLV" in a 24-bit field. [RFC5440] defines the METRIC
object with 32-bit metric value. Consequently, encoding for Latency
Variation (Jitter) Metric Value is defined as follows:
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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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Reserved | Latency variation (jitter) Metric |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Reserved (8 bits): Reserved field. This field MUST be set to zero on
transmission and MUST be ignored on receipt.
Latency variation (jitter) Metric (24 bits): Represents the end to
end Latency variation (jitter) quantified in units of microseconds
and MUST be encoded as integer value. With the maximum value
16,777,215 representing 16.777215 sec.
4.3. Packet Loss Metric
[OSPF-TE-EXPRESS] and [ISIS-TE-EXPRESS] defines "Unidirectional Link
Loss". Packet Loss Metric metric type of METRIC object in PCEP
encodes a function of the link's unidirectional loss metric of all
links along a P2P Path. Specifically, extending on the above
mentioned terminology:
The end to end Packet Loss for the path is represented by this
metric.
- A Packet loss of link L is denoted PL(L).
- A P2P packet loss metric for the Path P = function {PL(Lpi),
(i=1...K)}.
Specification of the "Function" used to drive end to end packet loss
metric of a path from packet loss metrics of individual links along
the path is beyond the scope of this document.
* T=15(IANA): Packet Loss metric
PCC MAY use this packet loss metric In PCReq to request a path
meeting the end to end packet loss requirement. In this case B bit
MUST be set to suggest a bound (a maximum) for the path packet loss
metric that must not be exceeded for the PCC to consider the computed
path as acceptable. The path metric must be less than or equal to
the value specified in the metric-value field.
PCC MAY also use this metric to ask PCE to optimize packet loss
during path computation, in this case B flag will be cleared.
PCE MAY use this packet loss metric In PCRep along with NO-PATH
object incase PCE cannot compute a path meeting this constraint. PCE
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MAY also use this metric to reply the computed end to end packet loss
metric to PCC.
4.3.1. Packet Loss Metric Value
[OSPF-TE-EXPRESS] and [ISIS-TE-EXPRESS] defines "Unidirectional Link
Loss Sub-TLV" in a 24-bit field. [RFC5440] defines the METRIC object
with 32-bit metric value. Consequently, encoding for Packet Loss
Metric Value is defined as follows:
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Reserved | Packet loss Metric |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Reserved (8 bits): Reserved field. This field MUST be set to zero on
transmission and MUST be ignored on receipt.
Packet loss Metric (24 bits): Represents the end to end packet loss
quantified as a percentage of packets lost and MUST be encoded as
integer. The basic unit is 0.000003%, with the maximum value
16,777,215 representing 50.331645% (16,777,215 * 0.000003%). This
value is the highest packet loss percentage that can be expressed.
4.4. Non-Understanding / Non-Support of Service Aware Path Computation
If the P bit is clear in the object header and PCE does not
understand or does not support service aware path computation it
SHOULD simply ignore this METRIC.
If the P Bit is set in the object header and PCE receives new METRIC
type in path request and it understands the METRIC type, but the PCE
is not capable of service aware path computation, the PCE MUST send a
PCErr message with a PCEP-ERROR Object Error-Type = 4 (Not supported
object) [RFC5440]. The path computation request MUST then be
cancelled.
If the PCE does not understand the new METRIC type, then the PCE MUST
send a PCErr message with a PCEP-ERROR Object Error-Type = 3 (Unknown
object) [RFC5440].
4.5. 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:
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o To indicate the metric that MUST be optimized by the path
computation algorithm (Latency, Latency-Variation or Loss)
o To indicate a bound on the path METRIC (Latency, Latency-Variation
or Loss) that MUST NOT be exceeded for the path to be considered
as acceptable by the PCC.
In a PCRep message, the METRIC object MAY be inserted so as to
provide the METRIC (Latency, Latency-Variation or Loss) for the
computed path. It MAY also be inserted within a PCRep with the 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 METRIC object as explained in [RFC5440]
are applicable to the new metric types as well.
In a PCReq message, a PCC MAY insert more than one METRIC object to
be optimized, in such a case PCE should find the path that is optimal
when both the metrics are considered together.
4.5.1. Examples
Example 1: If a PCC sends a path computation request to a PCE where
two metric to optimize are the latency and the packet loss, two
METRIC objects are inserted in the PCReq message:
o First METRIC object with B=0, T=13 (TBA - IANA), C=1, metric-
value=0x0000
o Second METRIC object with B=0, T=15 (TBA - IANA), C=1, metric-
value=0x0000
PCE in such a case should try to optimize both the metrics and find a
path with the minimum latency and packet loss, if a path can be found
by the PCE and there is no policy that prevents the return of the
computed metric, the PCE inserts two METRIC object with B=0, T=13
(TBA - IANA), metric-value= computed end to end latency and second
METRIC object with B=1, T=15 (TBA - IANA), metric-value= computed end
to end packet loss.
Example 2: If a PCC sends a path computation request to a PCE where
the metric to optimize is the latency and the packet loss must not
exceed the value of M, two METRIC objects are inserted in the PCReq
message:
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o First METRIC object with B=0, T=13 (TBA - IANA), C=1, metric-
value=0x0000
o Second METRIC object with B=1, T=15 (TBA - IANA), metric-value=M
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, the PCE inserts one METRIC object with B=0, T=13 (TBA -
IANA), metric-value= computed end to end latency. Additionally, the
PCE may insert a second METRIC object with B=1, T=15 (TBA - IANA),
metric-value= computed end to end packet loss.
5. Relationship with Objective function
[RFC5541] defines mechanism to specify an optimization criteria,
referred to as objective functions. The new metric types specified
in this document can continue to use the existing Objective function.
Minimum Cost Path (MCP) is one such objective function.
o A network comprises a set of N links {Li, (i=1...N)}.
o A path P is a list of K links {Lpi,(i=1...K)}.
o Metric of link L is denoted M(L). This can be any metric,
including the ones defined in this document.
o The cost of a path P is denoted C(P), where C(P) = sum
{M(Lpi),(i=1...K)}.
Name: Minimum Cost Path (MCP)
Description: Find a path P such that C(P) is minimized.
The new metric types for example latency (delay) can continue to use
the above objective function to find the minimum cost path where cost
is latency (delay). At the same time new objective functions can be
defined in future to optimize these new metric types.
6. Protocol Consideration
There is no change in the message format of Path Request and Reply
Message.
6.1. Inter domain Consideration
[RFC5441] describes the BRPC procedure to compute end to end
optimized inter domain path by cooperating PCEs. The network
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performance constraints can be applied end to end in similar manner
as IGP or TE cost.
All domains should have the same understanding of the METRIC
(Latency-Variation etc) for end-to-end inter-domain path computation
to make sense. Otherwise some form of Metric Normalization as
described in [RFC5441] MAY need to be applied.
6.1.1. Inter-AS Link
The IGP in each neighbor domain can advertise its inter-domain TE
link capabilities, this has been described in [RFC5316] (ISIS) and
[RFC5392] (OSPF). The network performance link properties are
described in [OSPF-TE-EXPRESS] and [ISIS-TE-EXPRESS], the same
properties must be advertised using the mechanism described in
[RFC5392] (OSPF) and [RFC5316] (ISIS).
6.1.2. Inter-Layer Consideration
PCEP supporting this draft SHOULD provide mechanism to support
different Metric requirements for different Layers. This is
important as the network performance metric would be different for
Packet and Optical (TDM, LSC etc) Layers. In order to allow
different Metric-Value to be applied within different network layers,
multiple METRIC objects of the same type MAY be present. In such a
case, the first METRIC object specifies an metric for the higher-
layer network, and subsequent METRIC objects specify objection
functions of the subsequent lower-layer networks.
6.2. Reoptimization Consideration
PCC can monitor the setup LSPs and incase of degradation of network
performance constraints, it MAY ask PCE for reoptimization as per
[RFC5440].
6.3. Point-to-Multipoint (P2MP)
This document defines the following optional types for the METRIC
object defined in [RFC5440] for P2MP TE LSPs. Additional metric
types for P2MP TE LSPs are to be added in a future revision
6.3.1. P2MP Latency Metric
P2MP latency metric type of METRIC object in PCEP encodes the path
latency metric for destination that observes the worst latency metric
among all destination of the P2MP tree. Specifically, extending on
the above mentioned terminology:
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- A P2MP Tree T comprises of a set of M destinations {Dest_j,
(j=1...M)}
- P2P latency metric of the Path to destination Dest_j is denoted by
LM(Dest_j).
- P2MP latency metric for the P2MP tree T = Maximum {LM(Dest_j),
(j=1...M)}.
Value for P2MP latency metric is to be assigned by IANA
6.3.2. P2MP Latency Variation Metric
P2MP latency variation metric type of METRIC object in PCEP encodes
the path latency variation metric for destination that observes the
worst latency variation metric among all destination of the P2MP
tree. Specifically, extending on the above mentioned terminology:
- A P2MP Tree T comprises of a set of M destinations {Dest_j,
(j=1...M)}
- P2P latency variation metric of the Path to destination Dest_j is
denoted by LVM(Dest_j).
- P2MP latency variation metric for the P2MP tree T = Maximum
{LVM(Dest_j), (j=1...M)}.
Value for P2MP latency variation metric is to be assigned by IANA
7. IANA Considerations
IANA has defined a registry for new METRIC type.
Type Meaning
13(TBD) Latency (delay) metric
14(TBD) Latency Variation (jitter) metric
15(TBD) Packet Loss metric
16(TBD) P2MP latency metric
17(TBD) P2MP latency variation metric
8. Security Considerations
This document defines three new METRIC Types which does not add any
new security concerns to PCEP protocol.
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9. Manageability Considerations
9.1. Control of Function and Policy
The only configurable item is the support of the new service-aware
METRICS on a PCE which MAY be controlled by a policy module. If the
new METRIC is not supported/allowed on a PCE, it MUST send a PCErr
message as specified in Section 4.4.
9.2. Information and Data Models
[PCEP-MIB] describes the PCEP MIB, there are no new MIB Objects for
this document.
9.3. 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].
9.4. Verify Correct Operations
Mechanisms defined in this document do not imply any new operation
verification requirements in addition to those already listed in
[RFC5440].
9.5. Requirements On Other Protocols
PCE requires the TED to be populated with network performance
information like link latency, latency variation and packet loss.
This mechanism is described in [OSPF-TE-EXPRESS] or
[ISIS-TE-EXPRESS].
9.6. Impact On Network Operations
Mechanisms defined in this document do not have any impact on network
operations in addition to those already listed in [RFC5440].
10. Acknowledgments
We would like to thank Young Lee, Venugopal Reddy, Reeja Paul,
Sandeep Kumar Boina, Suresh babu, Quintin Zhao and Chen Huaimo for
their useful comments and suggestions.
11. References
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11.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to
Indicate Requirement Levels", BCP 14,
RFC 2119, March 1997.
[RFC5440] Vasseur, JP. and JL. Le Roux, "Path
Computation Element (PCE) Communication
Protocol (PCEP)", RFC 5440, March 2009.
11.2. Informative References
[RFC5441] Vasseur, JP., Zhang, R., Bitar, N., and JL.
Le Roux, "A Backward-Recursive PCE-Based
Computation (BRPC) Procedure to Compute
Shortest Constrained Inter-Domain Traffic
Engineering Label Switched Paths", RFC 5441,
April 2009.
[RFC5316] Chen, M., Zhang, R., and X. Duan, "ISIS
Extensions in Support of Inter-Autonomous
System (AS) MPLS and GMPLS Traffic
Engineering", RFC 5316, December 2008.
[RFC5392] Chen, M., Zhang, R., and X. Duan, "OSPF
Extensions in Support of Inter-Autonomous
System (AS) MPLS and GMPLS Traffic
Engineering", RFC 5392, January 2009.
[RFC5541] Le Roux, JL., Vasseur, JP., and Y. Lee,
"Encoding of Objective Functions in the Path
Computation Element Communication Protocol
(PCEP)", RFC 5541, June 2009.
[RFC6374] Frost, D. and S. Bryant, "Packet Loss and
Delay Measurement for MPLS Networks",
RFC 6374, September 2011.
[MPLS-DELAY-FWK] Fu, X., Manral, V., McDysan, D., Malis, A.,
Giacalone, S., Betts, M., Wang, Q., and J.
Drake, "Traffic Engineering architecture for
services aware MPLS
[draft-fuxh-mpls-delay-loss-te-framework]",
Oct 2012.
[OSPF-TE-EXPRESS] Giacalone, S., Ward, D., Drake, J., Atlas,
A., and S. Previdi, "OSPF Traffic Engineering
(TE) Metric Extensions
Dhody, et al. Expires August 24, 2013 [Page 15]
Internet-Draft SERVICE-AWARE December 2012
[draft-ietf-ospf-te-metric-extensions]",
May 2012.
[ISIS-TE-EXPRESS] Previdi, S., Giacalone, S., Ward, D., Drake,
J., Atlas, A., and C. Filsfils, "IS-IS
Traffic Engineering (TE) Metric Extensions
[draft-previdi-isis-te-metric-extensions]",
Oct 2012.
[MPLS-TE-EXPRESS-PATH] Atlas, A., Drake, J., Ward, D., Giacalone,
S., Previdi, S., and C. Filsfils,
"Performance-based Path Selection for
Explicitly Routed LSPs
[draft-atlas-mpls-te-express-path]",
June 2012.
[PCEP-MIB] Kiran Koushik, A S., Stephan, E., Zhao, Q.,
King, D., and J. Hardwick, "PCE communication
protocol(PCEP) Management Information Base
[draft-ietf-pce-pcep-mib]", July 2012.
Appendix A. Contributor Addresses
Clarence Filsfils
Cisco Systems
EMail: cfilsfil@cisco.com
Siva Sivabalan
Cisco Systems
EMail: msiva@cisco.com
Stefano Previdi
Cisco Systems
EMail: sprevidi@cisco.com
Udayasree Palle
Huawei Technologies India Pvt Ltd
Leela Palace
Bangalore, Karnataka 560008
INDIA
EMail: udayasree.palle@huawei.com
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Authors' Addresses
Dhruv Dhody
Huawei Technologies India Pvt Ltd
Leela Palace
Bangalore, Karnataka 560008
INDIA
EMail: dhruv.dhody@huawei.com
Vishwas Manral
Hewlett-Packard Corp.
191111 Pruneridge Ave.
Cupertino, CA 95014
USA
EMail: vishwas.manral@hp.com
Zafar Ali
Cisco Systems
EMail: zali@cisco.com
George Swallow
Cisco Systems
EMail: swallow@cisco.com
Kenji Kumaki
KDDI Corporation
EMail: ke-kumaki@kddi.com
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