draft-ietf-mpls-entropy-lsp-ping-05.txt   rfc8012.txt 
MPLS Working Group N. Akiya Internet Engineering Task Force (IETF) N. Akiya
Internet-Draft Big Switch Networks Request for Comments: 8012 Big Switch Networks
Updates: 6790 (if approved) G. Swallow Updates: 6790 G. Swallow
Intended status: Standards Track C. Pignataro Category: Standards Track C. Pignataro
Expires: March 9, 2017 Cisco ISSN: 2070-1721 Cisco
A. Malis A. Malis
Huawei Technologies Huawei Technologies
S. Aldrin S. Aldrin
Google Google
September 5, 2016 November 2016
Label Switched Path (LSP) and Pseudowire (PW) Ping/Trace over Label Switched Path (LSP) and Pseudowire (PW) Ping/Trace
MPLS Network using Entropy Labels (EL) over MPLS Networks Using Entropy Labels (ELs)
draft-ietf-mpls-entropy-lsp-ping-05
Abstract Abstract
Multiprotocol Label Switching (MPLS) Label Switched Path (LSP) Ping Multiprotocol Label Switching (MPLS) Label Switched Path (LSP) ping
and Traceroute are methods used to test Equal-Cost Multipath (ECMP) and traceroute are methods used to test Equal-Cost Multipath (ECMP)
paths. Ping is known as a connectivity verification method and paths. Ping is known as a connectivity-verification method and
Traceroute as a fault isolation method, as described in RFC 4379. traceroute is known as a fault-isolation method, as described in RFC
When an LSP is signaled using the Entropy Label (EL) described in RFC 4379. When an LSP is signaled using the Entropy Label (EL) described
6790, the ability for LSP Ping and Traceroute operations to discover in RFC 6790, the ability for LSP ping and traceroute operations to
and exercise ECMP paths is lost for scenarios where Label Switching discover and exercise ECMP paths is lost for scenarios where Label
Routers (LSRs) apply different load balancing techniques. One such Switching Routers (LSRs) apply different load-balancing techniques.
scenario is when some LSRs apply EL-based load balancing while other One such scenario is when some LSRs apply EL-based load balancing
LSRs apply non-EL-based load balancing (e.g., IP). Another scenario while other LSRs apply load balancing that is not EL based (e.g.,
is when an EL-based LSP is stitched with another LSP which can be EL- IP). Another scenario is when an EL-based LSP is stitched with
based or non-EL-based. another LSP that can be EL based or not EL based.
This document extends the MPLS LSP Ping and Traceroute multipath This document extends the MPLS LSP ping and traceroute multipath
mechanisms in RFC 6424 to allow the ability of exercising LSPs which mechanisms in RFC 6424 to allow the ability of exercising LSPs that
make use of the EL. This document updates RFC 6790. make use of the EL. This document updates RFC 6790.
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 RFC 2119 [RFC2119].
Status of This Memo Status of This Memo
This Internet-Draft is submitted in full conformance with the This is an Internet Standards Track document.
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 This document is a product of the Internet Engineering Task Force
and may be updated, replaced, or obsoleted by other documents at any (IETF). It represents the consensus of the IETF community. It has
time. It is inappropriate to use Internet-Drafts as reference received public review and has been approved for publication by the
material or to cite them other than as "work in progress." Internet Engineering Steering Group (IESG). Further information on
Internet Standards is available in Section 2 of RFC 7841.
This Internet-Draft will expire on March 9, 2017. Information about the current status of this document, any errata,
and how to provide feedback on it may be obtained at
http://www.rfc-editor.org/info/rfc8012.
Copyright Notice Copyright Notice
Copyright (c) 2016 IETF Trust and the persons identified as the Copyright (c) 2016 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal This document is subject to BCP 78 and the IETF Trust's Legal
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to this document. Code Components extracted from this document must to this document. Code Components extracted from this document must
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described in the Simplified BSD License. described in the Simplified BSD License.
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 1. Introduction ....................................................3
1.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 3 1.1. Terminology ................................................5
1.2. Background . . . . . . . . . . . . . . . . . . . . . . . 4 1.1.1. Requirements Language ...............................6
2. Overview . . . . . . . . . . . . . . . . . . . . . . . . . . 5 1.2. Background .................................................6
3. Multipath Type 9 . . . . . . . . . . . . . . . . . . . . . . 7 2. Multipath Type {9} ..............................................7
4. Pseudowire Tracing . . . . . . . . . . . . . . . . . . . . . 7 3. Pseudowire Tracing ..............................................7
5. Entropy Label FEC . . . . . . . . . . . . . . . . . . . . . . 8 4. Entropy Label FEC ...............................................8
6. DS Flags: L and E . . . . . . . . . . . . . . . . . . . . . . 9 5. DS Flags: L and E ...............................................9
7. New Multipath Information Type: TBD4 . . . . . . . . . . . . 10 6. New Multipath Information Type {10} ............................10
8. Initiating LSR Procedures . . . . . . . . . . . . . . . . . . 11 7. Initiating LSR Procedures ......................................12
9. Responder LSR Procedures . . . . . . . . . . . . . . . . . . 13 8. Responder LSR Procedures .......................................14
9.1. IP-based Load Balancer & Not Pushing ELI/EL . . . . . . . 14 8.1. IP-Based Load Balancer That Does Not Push ELI/EL ..........15
9.2. IP Based Load Balancer & Pushes ELI/EL . . . . . . . . . 14 8.2. IP-Based Load Balancer That Pushes ELI/EL .................15
9.3. Label-based Load Balancer & Not Pushing ELI/EL . . . . . 15 8.3. Label-Based Load Balancer That Does Not Push ELI/EL .......16
9.4. Label-based Load Balancer & Pushes ELI/EL . . . . . . . . 16 8.4. Label-Based Load Balancer That Pushes ELI/EL ..............17
9.5. Flow-Aware MS-PW Stitching LSR . . . . . . . . . . . . . 17 8.5. Flow-Aware MS-PW Stitching LSR ............................18
10. Supported and Unsupported Cases . . . . . . . . . . . . . . . 17 9. Supported and Unsupported Cases ................................18
11. Security Considerations . . . . . . . . . . . . . . . . . . . 19 10. Security Considerations .......................................20
12. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 19 11. IANA Considerations ...........................................21
12.1. Entropy Label FEC . . . . . . . . . . . . . . . . . . . 19 11.1. Entropy Label FEC ........................................21
12.2. DS Flags . . . . . . . . . . . . . . . . . . . . . . . . 19 11.2. DS Flags .................................................21
12.3. Multipath Type . . . . . . . . . . . . . . . . . . . . . 20 11.3. Multipath Type ...........................................21
13. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 20 12. References ....................................................22
14. Contributing Authors . . . . . . . . . . . . . . . . . . . . 20 12.1. Normative References .....................................22
15. References . . . . . . . . . . . . . . . . . . . . . . . . . 20 12.2. Informative References ...................................22
15.1. Normative References . . . . . . . . . . . . . . . . . . 20 Acknowledgements ..................................................23
15.2. Informative References . . . . . . . . . . . . . . . . . 21 Contributors ......................................................23
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 21 Authors' Addresses ................................................23
1. Introduction 1. Introduction
[RFC4379] describes LSP traceroute as an operation where the
initiating LSR sends a series of MPLS echo requests towards the same
destination. The first packet in the series has the TTL set to 1.
When the echo reply is received from the LSR one hop away, the second
echo request in the series is sent with the TTL set to 2. For each
additional echo request, the TTL is incremented by one until a
response is received from the intended destination. The initiating
LSR discovers and exercises ECMP by obtaining Multipath Information
from each transit LSR and using a specific destination IP address or
specific entropy label.
From here on, the notation {x, y, z} refers to Multipath Information
Types x, y, or z. Multipath Information Types are defined in
Section 3.3 of [RFC4379] .
The LSR initiating LSP ping sends an MPLS echo request with the
Multipath Information. This Multipath Information is described in
the echo request's DDMAP TLV and may contain a set of IP addresses or
a set of labels. Multipath Information Types {2, 4, 8} carry a set
of IP addresses, and the Multipath Information Type {9} carries a set
of labels. The responder LSR (the receiver of the MPLS echo request)
will determine the subset of initiator-specified Multipath
Information, which load balances to each downstream (outgoing)
interface. The responder LSR sends an MPLS echo reply with the
resulting Multipath Information per downstream (outgoing interface)
back to the initiating LSR. The initiating LSR is then able to use a
specific IP destination address or a specific label to exercise a
specific ECMP path on the responder LSR.
The current behavior is problematic in the following scenarios:
o The initiating LSR sends the IP Multipath Information, but the
responder LSR load balances on labels.
o The initiating LSR sends the Label Multipath Information, but the
responder LSR load balances on IP addresses.
o The initiating LSR sends the existing Multipath Information to an
LSR that pushes ELI/EL in the label stack, but the initiating LSR
can only continue to discover and exercise specific paths of the
ECMP if the LSR that pushes ELI/EL responds with both IP addresses
and the associated EL corresponding to each IP address. This is
because:
* An ELI/EL-pushing LSR that is a stitching point will load
balance based on the IP address.
* Downstream LSR(s) of an ELI/EL-pushing LSR may load balance
based on ELs.
o The initiating LSR sends existing Multipath Information to an ELI/
EL-pushing LSR, but the initiating LSR can only continue to
discover and exercise specific paths of ECMP if the ELI/EL-pushing
LSR responds with both labels and the associated EL corresponding
to the label. This is because:
* An ELI/EL-pushing LSR that is a stitching point will load
balance based on the EL from the previous LSP and push a new
EL.
* Downstream LSR(s) of ELI/EL-pushing LSR may load balance based
on new ELs.
The above scenarios demonstrate that the existing Multipath
Information is insufficient when LSP traceroute is used on an LSP
with entropy labels [RFC6790]. This document defines a new Multipath
Information Type to be used in the DDMAP of MPLS echo request/reply
packets for [RFC6790] LSPs.
The responder LSR can reply with empty Multipath Information if no IP
address set or if no label set is received with the Multipath
Information. An empty return is also possible if an initiating LSR
sends Multipath Information of one type, IP Address or Label, but the
responder LSR load balances on the other type. To disambiguate
between the two results, this document introduces new flags in the
DDMAP TLV to allow the responder LSR to describe the load-balancing
technique being used.
To use this enhanced method end-to-end, all LSRs along the LSP need
to be able to understand the new flags and the new Multipath
Information Type. Mechanisms to verify this condition are outside of
the scope of this document. The rest of the requirements are
detailed in the initiating LSR and responder LSR procedures. Two
additional DS Flags are defined for the DDMAP TLV in Section 6.
These two flags are used by the responder LSR to describe its load-
balancing behavior on a received MPLS echo request.
Note that the terms "IP-Based Load Balancer" and "Label-Based Load
Balancer" are in context of how a received MPLS echo request is
handled by the responder LSR.
1.1. Terminology 1.1. Terminology
The following acronyms and terms are used in this document: The following abbreviations and terms are used in this document:
o MPLS - Multiprotocol Label Switching. o MPLS: Multiprotocol Label Switching.
o LSP - Label Switched Path. o LSP: Label Switched Path.
o Stitched LSP - Stitched Label Switched Paths combine several LSPs o Stitched LSP: Stitched Label Switched Paths combine several LSPs
such that a single end-to-end (e2e) LSP is realized. [RFC6424] such that a single end-to-end LSP is realized. [RFC6424]
describes LSP Ping for Stitched LSPs. describes LSP ping for Stitched LSPs.
o LSR - Label Switching Router. o LSR: Label Switching Router.
o FEC - Forwarding Equivalence Class. o FEC: Forwarding Equivalence Class.
o ECMP - Equal-Cost Multipath. o ECMP: Equal-Cost Multipath.
o EL - Entropy Label. o EL: Entropy Label.
o ELI - Entropy Label Indicator. o ELI: Entropy Label Indicator.
o GAL - Generic Associated Channel Label. o GAL: Generic Associated Channel Label.
o MS-PW - Multi-Segment Pseudowire. o MS-PW: Multi-Segment Pseudowire.
o Initiating LSR - LSR which sends an MPLS echo request. o Initiating LSR: An LSR that sends an MPLS echo request.
o Responder LSR - LSR which receives an MPLS echo request and sends o Responder LSR: An LSR that receives an MPLS echo request and sends
an MPLS echo reply. an MPLS echo reply.
o IP-Based Load Balancer - LSR which load balances on fields from an o IP-Based Load Balancer: An LSR that load balances on fields from
IP header (and possibly fields from upper layers), and does not an IP header (and possibly fields from upper layers) and does not
consider an entropy label from an MPLS label stack (i.e., flow consider an entropy label from an MPLS label stack (i.e., flow
label [RFC6391] or entropy label [RFC6790]) for load balancing label [RFC6391] or entropy label [RFC6790]) for load-balancing
purposes. purposes.
o Label-Based Load Balancer - LSR which load balances on an entropy o Label-Based Load Balancer: An LSR that load balances on an entropy
label from an MPLS label stack (i.e., flow label or entropy label from an MPLS label stack (i.e., flow label or entropy label)
label), and does not consider fields from an IP header (and and does not consider fields from an IP header (and possibly
possibly fields from upper layers) for load balancing purposes. fields from upper layers) for load-balancing purposes.
o Label and IP-Based Load Balancer - LSR which load balances on both o Label and IP-Based Load Balancer: An LSR that load balances on
entropy labels from an MPLS label stack and fields from an IP both entropy labels from an MPLS label stack and fields from an IP
header (and possibly fields from upper layers). header (and possibly fields from upper layers).
1.1.1. 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 RFC 2119 [RFC2119].
1.2. Background 1.2. Background
MPLS implementations employ a wide variety of load balancing MPLS implementations employ a wide variety of load-balancing
techniques in terms of fields used for hash "keys". The mechanisms techniques in terms of fields used for hash "keys". The mechanisms
in [RFC4379] and updated by [RFC6424] are designed to provide in [RFC4379] and updated by [RFC6424] are designed to provide
multipath support for a subset of techniques. The intent of this multipath support for a subset of techniques. The intent of this
document is to provide multipath support for the supported techniques document is to provide multipath support for the supported techniques
which are compromised by the use of ELs [RFC6790]. Section 10 that are compromised by the use of ELs [RFC6790]. Section 9
describes supported and unsupported cases, and it may be useful for describes supported and unsupported cases, and it may be useful for
the reader to first review this section. the reader to first review this section.
The Downstream Detailed Mapping (DDMAP) TLV [RFC6424] provides The Downstream Detailed Mapping (DDMAP) TLV [RFC6424] provides
Multipath Information which can be used by an LSP Ping initiator to Multipath Information, which can be used by an LSP ping initiator to
trace and validate ECMP paths between an ingress and egress. The trace and validate ECMP paths between an ingress and egress. The
Multipath Information encodings defined by [RFC6424] are sufficient Multipath Information encodings defined by [RFC6424] are sufficient
when all the LSRs along the path(s), between ingress and egress, when all the LSRs along the path(s), between ingress and egress,
consider the same set of "keys" as input for load balancing consider the same set of "keys" as input for load-balancing
algorithms, e.g., either all IP-based or all label-based. algorithms, e.g., either all IP based or all label based.
With the introduction of [RFC6790], some LSRs may perform load With the introduction of [RFC6790], some LSRs may perform load
balancing based on labels while others may be IP-based. This results balancing based on labels while others may be IP based. This results
in an LSP Ping initiator that is unable to trace and validate all the in an LSP ping initiator that is unable to trace and validate all the
ECMP paths in the following scenarios: ECMP paths in the following scenarios:
o One or more transit LSRs along an LSP with ELI/EL in the label o One or more transit LSRs along an LSP with ELI/EL in the label
stack do not perform ECMP load balancing based on EL (hashes based stack do not perform ECMP load balancing based on EL (hashes based
on "keys" including the IP destination address). This scenario is on "keys" including the IP destination address). This scenario is
not only possible but quite common due to transit LSRs not not only possible but quite common due to transit LSRs not
implementing [RFC6790] or transit LSRs implementing [RFC6790], but implementing [RFC6790] or transit LSRs implementing [RFC6790] but
not implementing the suggested transit LSR behavior in Section 4.3 not implementing the suggested transit LSR behavior in Section 4.3
of [RFC6790]. of [RFC6790].
o Two or more LSPs stitched together with at least one of these LSPs o Two or more LSPs stitched together with at least one of these LSPs
pushing ELI/EL into the label stack. pushing ELI/EL into the label stack.
These scenarios can be quite common because deployments of [RFC6790] These scenarios can be quite common because deployments of [RFC6790]
typically have a mixture of nodes that support ELI/EL and nodes that typically have a mixture of nodes that support ELI/EL and nodes that
do not. There will also typically be a mixture of areas that support do not. There will also typically be a mixture of areas that support
ELI/EL and areas that do not. ELI/EL and areas that do not.
As pointed out in [RFC6790], the procedures of [RFC4379] (and As pointed out in [RFC6790], the procedures of [RFC4379] (and
consequently of [RFC6424]) with respect to Multipath Information Type consequently of [RFC6424]) with respect to Multipath Information Type
{9} are incomplete. However, [RFC6790] does not actually update {9} are incomplete. However, [RFC6790] does not actually update
[RFC4379]. Further, the specific EL location is not clearly defined, [RFC4379]. Further, the specific EL location is not clearly defined,
particularly in the case of Flow Aware Pseudowires [RFC6391]. This particularly in the case of Flow-Aware Pseudowires [RFC6391]. This
document defines a new FEC Stack sub-TLV for the entropy label. document defines a new FEC Stack sub-TLV for the entropy label.
Section 3 of this document updates the procedures for Multipath Section 2 of this document updates the procedures for the Multipath
Information Type {9} described in [RFC4379] and applicable to Information Type {9} that are described in [RFC4379] and that are
[RFC6424]. The rest of this document describes extensions required applicable to [RFC6424]. The rest of this document describes
to restore ECMP discovery and tracing capabilities for the scenarios extensions required to restore ECMP discovery and tracing
described. capabilities for the scenarios described.
[RFC4379], [RFC6424], and this document will support IP-based load [RFC4379], [RFC6424], and this document will support IP-based load
balancers and label-based load balancers which limit their hash to balancers and label-based load balancers that limit their hash to the
the first (top-most) or only entropy label in the label stack. Other first (top-most) or only entropy label in the label stack. Other use
use cases (refer to Section 10) are out of scope. cases (refer to Section 9) are out of scope.
2. Overview
[RFC4379] describes LSP traceroute as an operation where the
initiating LSR sends a series of MPLS echo requests towards the same
destination. The first packet in the series has the TTL set to 1.
When the echo reply is received from the LSR one hop away, the second
echo request in the series is sent with the TTL set to 2. For each
additional echo request the TLL is incremented by one until a
response is received from the intended destination. The initiating
LSR discovers and exercises ECMP by obtaining Multipath Information
from each transit LSR and using a specific destination IP address or
specific entropy label.
From here on, the notation {x, y, z} refers to Multipath Information
Types x, y, or z. Multipath Information Types are defined in
Section 3.3 of [RFC4379].
The LSR initiating LSP Ping sends an MPLS echo request with Multipath
Information. This Multipath Information is described in the echo
request's DDMAP TLV, and may contain a set of IP addresses or a set
of labels. Multipath Information Types {2, 4, 8} carry a set of IP
addresses, and Multipath Information Type {9} carries a set of
labels. The responder LSR (the receiver of the MPLS echo request)
will determine the subset of initiator-specified Multipath
Information which load balances to each downstream (outgoing)
interface. The responder LSR sends an MPLS echo reply with resulting
Multipath Information per downstream (outgoing interface) back to the
initiating LSR. The initiating LSR is then able to use a specific IP
destination address or a specific label to exercise a specific ECMP
path on the responder LSR.
The current behavior is problematic in the following scenarios:
o The initiating LSR sends IP Multipath Information, but the
responder LSR load balances on labels.
o The initiating LSR sends Label Multipath Information, but the
responder LSR load balances on IP addresses.
o The initiating LSR sends existing Multipath Information to an LSR
which pushes ELI/EL in the label stack, but the initiating LSR can
only continue to discover and exercise specific paths of the ECMP,
if the LSR which pushes ELI/EL responds with both IP addresses and
the associated EL corresponding to each IP address. This is
because:
* An ELI/EL-pushing LSR that is a stitching point will load
balance based on the IP address.
* Downstream LSR(s) of an ELI/EL-pushing LSR may load balance
based on ELs.
o The initiating LSR sends existing Multipath Information to an ELI/
EL-pushing LSR, but the initiating LSR can only continue to
discover and exercise specific paths of ECMP, if the ELI/EL-
pushing LSR responds with both labels and the associated EL
corresponding to the label. This is because:
* An ELI/EL-pushing LSR that is a stitching point will load
balance based on the EL from the previous LSP and pushes a new
EL.
* Downstream LSR(s) of ELI/EL-pushing LSR may load balance based
on new ELs.
The above scenarios demonstrate the existing Multipath Information is
insufficient when LSP traceroute is used on an LSP with entropy
labels [RFC6790]. This document defines a new Multipath Information
Type to be used in the DDMAP of MPLS echo request/reply packets for
[RFC6790] LSPs.
The responder LSR can reply with empty Multipath Information if no IP
address is set or label set is received with the Multipath
Information. An empty return is also possible if an initiating LSR
sends Multipath Information of one type, IP Address or Label, but the
responder LSR load balances on the other type. To disambiguate
between the two results, this document introduces new flags in the
DDMAP TLV to allow the responder LSR to describe the load balancing
technique being used.
To use this enhanced method end-to-end, all LSRs along the LSP need
to be able to understand the new flags and the new Multipath
Information Type. Mechanisms to verify this condition are outside of
the scope of this document. The rest of the requirements are
detailed in the initiating LSR and responder LSR procedures. Two
additional DS Flags are defined for the DDMAP TLV in Section 6.
These two flags are used by the responder LSR to describe its load
balance behavior on a received MPLS echo request.
Note that the terms "IP-Based Load Balancer" and "Label-Based Load
Balancer" are in context of how a received MPLS echo request is
handled by the responder LSR.
3. Multipath Type 9 2. Multipath Type {9}
[RFC4379] defined Multipath Type {9} for tracing of LSPs where label- [RFC4379] defined Multipath Type {9} for the tracing of LSPs where
based load balancing is used. However, as pointed out in [RFC6790], label-based load balancing is used. However, as pointed out in
the procedures for using this type are incomplete as the specific [RFC6790], the procedures for using this type are incomplete as the
location of the label was not defined. It was assumed that the specific location of the label was not defined. It was assumed that
presence of Multipath Type {9} implied the value of the bottom-of- the presence of Multipath Type {9} implied that the value of the
stack label should be varied by the values indicated by multipath to bottom-of-stack label should be varied by the values indicated by the
determine the respective outgoing interfaces. multipath to determine the respective outgoing interfaces.
Section 5 defines a new FEC-Stack sub-TLV to indicate an entropy Section 4 defines a new FEC-Stack sub-TLV to indicate an entropy
label. These labels MAY appear anywhere in a label stack. label. These labels MAY appear anywhere in a label stack.
Multipath Type {9} applies to the first label in the label stack that Multipath Type {9} applies to the first label in the label stack that
corresponds to an EL-FEC. If no such label is found, it applies to corresponds to an EL-FEC. If no such label is found, it applies to
the label at the bottom of the label stack. the label at the bottom of the label stack.
4. Pseudowire Tracing 3. Pseudowire Tracing
This section defines procedures for tracing pseudowires. These This section defines procedures for tracing Pseudowires. These
procedures pertain to the use of Multipath Information Type {9} as procedures pertain to the use of Multipath Information Type {9} as
well as Type {TBD4}. In all cases below, when a control word is in well as Type {10}. In all cases below, when a control word is in
use, the N-flag in the DDMAP MUST be set. Note that when a control use, the N flag in the DDMAP MUST be set. Note that when a control
word is not in use, the returned DDMAPs may not be accurate. word is not in use, the returned DDMAPs may not be accurate.
In order to trace a non-flow-aware Pseudowire, the initiator includes In order to trace a Pseudowire that is not flow aware, the initiator
an EL-FEC instead of the appropriate PW FEC at the bottom of the FEC includes an EL-FEC instead of the appropriate PW FEC at the bottom of
stack. Tracing in this way will cause compliant routers to return the FEC Stack. Tracing in this way will cause compliant routers to
the proper outgoing interface. Note that this procedure only traces return the proper outgoing interface. Note that this procedure only
to the end of the MPLS LSP that is under test and will not verify the traces to the end of the MPLS LSP that is under test and will not
PW FEC. To actually verify the PW FEC or in the case of a MS-PW, to verify the PW FEC. To actually verify the PW FEC or in the case of a
determine the next pseudowire label value, the initiator MUST repeat MS-PW, to determine the next Pseudowire label value, the initiator
that step of the trace (i.e., repeating the TTL value used) but with MUST repeat that step of the trace (i.e., repeating the TTL value
the FEC Stack modified to contain the appropriate PW FEC. Note that used) but with the FEC Stack modified to contain the appropriate PW
these procedures are applicable to scenarios where an initiator is FEC. Note that these procedures are applicable to scenarios where an
able to vary the bottom label (i.e., Pseudowire label). Possible initiator is able to vary the bottom label (i.e., Pseudowire label).
scenarios are tracing multiple non-flow-aware Pseudowires on the same Possible scenarios are tracing multiple Pseudowires that are not flow
endpoints or tracing a non-flow-aware Pseudowire provisioned with aware on the same endpoints or tracing a Pseudowire that is not flow-
multiple Pseudowire labels. aware provisioned with multiple Pseudowire labels.
In order to trace a flow-aware Pseudowire [RFC6391], the initiator In order to trace a flow-aware Pseudowire [RFC6391], the initiator
includes an EL FEC at the bottom of the FEC Stack and pushes the includes an EL FEC at the bottom of the FEC Stack and pushes the
appropriate PW FEC onto the FEC Stack. appropriate PW FEC onto the FEC Stack.
In order to trace through non-compliant routers, the initiator forms In order to trace through routers that are not compliant, the
an MPLS echo request message and includes a DDMAP with Multipath Type initiator forms an MPLS echo request message and includes a DDMAP
{9}. For a non-flow-aware Pseudowire it includes the appropriate PW with the Multipath Type {9}. For a Pseudowire that is not flow
FEC in the FEC Stack. For a flow-aware Pseudowire, the initiator aware, it includes the appropriate PW FEC in the FEC Stack. For a
includes a Nil FEC at the bottom of the FEC Stack and pushes the flow- aware Pseudowire, the initiator includes a Nil FEC at the
appropriate PW FEC onto the FEC Stack. bottom of the FEC Stack and pushes the appropriate PW FEC onto the
FEC Stack.
5. Entropy Label FEC 4. Entropy Label FEC
The entropy label indicator (ELI) is a reserved label that has no The ELI is a reserved label that has no associated explicit FEC, and
explicit FEC associated, and has label value 7 assigned from the has the label value 7 assigned from the reserved range. Use the Nil
reserved range. Use the Nil FEC as the Target FEC Stack sub-TLV to FEC as the Target FEC Stack sub-TLV to account for ELI in a Target
account for ELI in a Target FEC Stack TLV. FEC Stack TLV.
The entropy label (EL) is a special purpose label with the label The EL is a special-purpose label with the label value being
value being discretionary (i.e., the label value is not from the discretionary (i.e., the label value is not from the reserved range).
reserved range). For LSP verification mechanics to perform its For LSP verification mechanics to perform its purpose, it is
purpose, it is necessary for a Target FEC Stack sub-TLV to clearly necessary for a Target FEC Stack sub-TLV to clearly describe the EL,
describe the EL, particularly in the scenario where the label stack particularly in the scenario where the label stack does not carry ELI
does not carry ELI (e.g., flow-aware Pseudowire [RFC6391]). (e.g., flow-aware Pseudowire [RFC6391]). Therefore, this document
Therefore, this document defines an EL FEC sub-TLV (TBD1, see defines an EL FEC sub-TLV (33, see Section 11.1) that allows a Target
Section 12.1) to allow a Target FEC Stack sub-TLV to be added to the FEC Stack sub-TLV to be added to the Target FEC Stack to account for
Target FEC Stack to account for EL. EL.
The Length is 4. Labels are 20-bit values treated as numbers. The Length is 4. Labels are 20-bit values treated as numbers.
0 1 2 3 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 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Label | MBZ | | Label | MBZ |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 1: Entropy Label FEC Figure 1: Entropy Label FEC
Label is the actual label value inserted in the label stack; the MBZ "Label" is the actual label value inserted in the label stack; the
field MUST be zero when sent and ignored on receipt. "MBZ" field MUST be zero when sent and ignored on receipt.
6. DS Flags: L and E 5. DS Flags: L and E
Two flags, L and E, are added to the DS Flags field of the DDMAP TLV. Two flags, L and E, are added to the DS Flags field of the DDMAP TLV.
Both flags MUST NOT be set in echo request packets when sending, and Both flags MUST NOT be set in the echo request packets when sending
SHOULD be ignored when received. Zero, one or both new flags MUST be and SHOULD be ignored when received. Zero, one, or both new flags
set in echo reply packets. MUST be set in the echo reply packets.
DS Flags DS Flags
-------- --------
0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7
+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+
| MBZ |L|E|I|N| | MBZ |L|E|I|N|
+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+
RFC-Editor-Note: Please update the above figure to place the flag E
in the bit number TBD2 and the flag L in the bit number TBD3.
Flag Name and Meaning Flag Name and Meaning
---- ---------------- ---- ----------------
L Label-based load balance indicator L Label-based load balance indicator
This flag MUST be cleared in the echo request. An LSR This flag MUST be cleared in the echo request. An LSR
which performs load balancing on a label MUST set this that performs load balancing on a label MUST set this
flag in the echo reply. An LSR which performs load flag in the echo reply. An LSR that performs load
balancing on IP MUST NOT set this flag in the echo balancing on IP MUST NOT set this flag in the echo
reply. reply.
E ELI/EL push indicator E ELI/EL push indicator
This flag MUST be cleared in the echo request. An LSR This flag MUST be cleared in the echo request. An LSR
which pushes ELI/EL MUST set this flag in the echo that pushes ELI/EL MUST set this flag in the echo
reply. An LSR which does not push ELI/EL MUST NOT set reply. An LSR that does not push ELI/EL MUST NOT set
this flag in the echo reply. this flag in the echo reply.
The two flags result in four load balancing techniques which the echo The two flags result in four load-balancing techniques, which the
reply generating LSR can indicate: echo reply generating LSR can indicate:
o {L=0, E=0} LSR load balances based on IP and does not push ELI/EL. o {L=0, E=0} LSR load balances based on IP and does not push ELI/EL.
o {L=0, E=1} LSR load balances based on IP and pushes ELI/EL. o {L=0, E=1} LSR load balances based on IP and pushes ELI/EL.
o {L=1, E=0} LSR load balances based on labels and does not push o {L=1, E=0} LSR load balances based on labels and does not push
ELI/EL. ELI/EL.
o {L=1, E=1} LSR load balances based on labels and pushes ELI/EL. o {L=1, E=1} LSR load balances based on labels and pushes ELI/EL.
7. New Multipath Information Type: TBD4 6. New Multipath Information Type {10}
One new Multipath Information Type is added to be used in DDMAP TLV. One new Multipath Information Type is added to be used in DDMAP TLV.
This new Multipath Type has the value of TBD4. This new Multipath Type has the value of 10.
Key Type Multipath Information Key Type Multipath Information
--- ---------------- --------------------- --- ---------------- ---------------------
TBD4 IP and Label set IP addresses and label prefixes 10 IP and Label set IP addresses and label prefixes
Multipath Type TBD4 is comprised of three sections. The first Multipath Information Type {10} is comprised of three sections. The
section describes the IP address set. The second section describes first section describes the IP address set. The second section
the label set. The third section describes another label set which describes the label set. The third section describes another label
associates to either the IP address set or the label set specified in set, which associates to either the IP address set or the label set
the other sections. specified in the other sections.
Multipath Information Type TBD4 has following format: Multipath Information Type {10} has the following format:
0 1 2 3 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 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|IPMultipathType| IP Multipath Length | Reserved(MBZ) | |IPMultipathType| IP Multipath Length | Reserved(MBZ) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
~ ~ ~ ~
| (IP Multipath Information) | | (IP Multipath Information) |
~ ~ ~ ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|LbMultipathType| Label Multipath Length | Reserved(MBZ) | |LbMultipathType| Label Multipath Length | Reserved(MBZ) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
~ ~ ~ ~
| (Label Multipath Information) | | (Label Multipath Information) |
~ ~ ~ ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Assoc Label Multipath Length | Reserved(MBZ) | | Assoc. Label Multipath Length | Reserved(MBZ) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
~ ~ ~ ~
| (Associated Label Multipath Information) | | (Associated Label Multipath Information) |
~ ~ ~ ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 2: Multipath Information Type TBD4 Figure 2: Multipath Information Type {10}
o IPMultipathType o IPMultipathType
* 0 when "IP Multipath Information" is omitted. Otherwise, one * 0 when "IP Multipath Information" is omitted. Otherwise, one
of the IP Multipath Information values: {2, 4, 8}. of the IP Multipath Information values: {2, 4, 8}.
o IP Multipath Information o IP Multipath Information
* This section is omitted when "IPMultipathType" is 0. * This section is omitted when "IPMultipathType" is 0.
Otherwise, this section reuses IP Multipath Information from Otherwise, this section reuses the IP Multipath Information
[RFC4379]. Specifically, Multipath Information for values {2, from [RFC4379]. Specifically, Multipath Information for values
4, 8} can be used. {2, 4, 8} can be used.
o LbMultipathType o LbMultipathType
* 0 when "Label Multipath Information" is omitted. Otherwise, * 0 when the "Label Multipath Information" is omitted.
Label Multipath Information value {9}. Otherwise, the Label Multipath Information value {9}.
o Label Multipath Information o Label Multipath Information
* This section is omitted when "LbMultipathType" is 0. * This section is omitted when the "LbMultipathType" is 0.
Otherwise, this section reuses Label Multipath Information from Otherwise, this section reuses the Label Multipath Information
[RFC4379]. Specifically, Multipath Information for value {9} from [RFC4379]. Specifically, the Multipath Information for
can be used. value {9} can be used.
o Associated Label Multipath Information o Associated Label Multipath Information
* "Assoc Label Multipath Length" is a 16-bit field of Multipath * "Associated Label Multipath Length" is a 16-bit field of
Information which indicates the length in octets of the Multipath Information that indicates the length in octets of
Associated Label Multipath Information. the Associated Label Multipath Information.
* "Associated Label Multipath Information" is a list of labels * "Associated Label Multipath Information" is a list of labels
with each label described in 24 bits. This section MUST be with each label described in 24 bits. This section MUST be
omitted in an MPLS echo request message. A midpoint which omitted in an MPLS echo request message. A midpoint that
pushes ELI/EL labels SHOULD include "Assoc Label Multipath pushes ELI/EL labels SHOULD include "Associated Label Multipath
Information" in its MPLS echo reply message, along with either Information" in its MPLS echo reply message, along with either
"IP Multipath Information" or "Label Multipath Information". "IP Multipath Information" or "Label Multipath Information".
Each specified associated label described in this section maps Each specified associated label described in this section maps
to a specific IP address OR label described in the "IP to a specific IP address OR label described in the "IP
Multipath Information" section or "Label Multipath Information" Multipath Information" section or the "Label Multipath
section. For example, if three IP addresses are specified in Information" section. For example, if three IP addresses are
the "IP Multipath Information" section, then there MUST be specified in the "IP Multipath Information" section, then there
three labels described in this section. The first label maps MUST be three labels described in this section. The first
to the first IP address specified, the second label maps to the label maps to the first IP address specified, the second label
second IP address specified, and the third label maps to the maps to the second IP address specified, and the third label
third IP address specified. maps to the third IP address specified.
When a section is omitted, the length for that section MUST be set to When a section is omitted, the length for that section MUST be set to
zero. zero.
8. Initiating LSR Procedures 7. Initiating LSR Procedures
The following procedure is described in terms of an EL_LSP boolean The following procedure is described in terms of an EL_LSP boolean
maintained by the initiating LSR. This value controls the Multipath maintained by the initiating LSR. This value controls the Multipath
Information Type to be used in the transmitted echo request packets. Information Type to be used in the transmitted echo request packets.
When the initiating LSR is transmitting an echo request packet with When the initiating LSR is transmitting an echo request packet with
DDMAP with a non-zero Multipath Information Type, then the EL_LSP DDMAP with a non-zero Multipath Information Type, then the EL_LSP
boolean MUST be consulted to determine the Multipath Information Type boolean MUST be consulted to determine the Multipath Information Type
to use. to use.
In addition to procedures described in [RFC4379], as updated by In addition to the procedures described in [RFC4379], as updated by
Section 3 and [RFC6424], the initiating LSR MUST operate with the Section 2 and [RFC6424], the initiating LSR MUST operate with the
following procedures: following procedures:
o When the initiating LSR pushes ELI/EL, initialize EL_LSP=True. o When the initiating LSR pushes ELI/EL, initialize EL_LSP=True.
Else set EL_LSP=False. Else, set EL_LSP=False.
o When the initiating LSR is transmitting a non-zero Multipath o When the initiating LSR is transmitting a non-zero Multipath
Information Type: Information Type:
* If (EL_LSP), the initiating LSR MUST use Multipath Information * If (EL_LSP), the initiating LSR MUST use the Multipath
Type {TBD4} unless the responder LSR cannot handle Type {TBD4}. Information Type {10} unless the responder LSR cannot handle
When the initiating LSR is transmitting Multipath Information Type {10}. When the initiating LSR is transmitting the
Type {TBD4}, both "IP Multipath Information" and "Label Multipath Information Type {10}, both "IP Multipath
Multipath Information" MUST be included, and "Associated Label Information" and "Label Multipath Information" MUST be
Multipath Information" MUST be omitted (NULL). included, and "Associated Label Multipath Information" MUST be
omitted (NULL).
* Else the initiating LSR MAY use Multipath Information Type {2, * Else, the initiating LSR MAY use the Multipath Information Type
4, 8, 9, TBD4}. When the initiating LSR is transmitting {2, 4, 8, 9, 10}. When the initiating LSR is transmitting the
Multipath Information Type {TBD4} in this case, "IP Multipath Multipath Information Type {10} in this case, "IP Multipath
Information" MUST be included, and "Label Multipath Information" MUST be included, and "Label Multipath
Information" and "Associated Label Multipath Information" MUST Information" and "Associated Label Multipath Information" MUST
be omitted (NULL). be omitted (NULL).
o When the initiating LSR receives an echo reply with {L=0, E=1} in o When the initiating LSR receives an echo reply with {L=0, E=1} in
the DS flags with valid contents, set EL_LSP=True. the DS Flags with valid contents, set EL_LSP=True.
In the following conditions, the initiating LSR may have lost the In the following conditions, the initiating LSR may have lost the
ability to exercise specific ECMP paths. The initiating LSR MAY ability to exercise specific ECMP paths. The initiating LSR MAY
continue with "best effort" in the following cases: continue with "best effort" in the following cases:
o Received echo reply contains empty Multipath Information. o Received echo reply contains empty Multipath Information.
o Received echo reply contains {L=0, E=<any>} DS flags, but does not o Received echo reply contains {L=0, E=<any>} DS Flags, but does not
contain IP Multipath Information. contain IP Multipath Information.
o Received echo reply contains {L=1, E=<any>} DS flags, but does not o Received echo reply contains {L=1, E=<any>} DS Flags, but does not
contain Label Multipath Information. contain Label Multipath Information.
o Received echo reply contains {L=<any>, E=1} DS flags, but does not o Received echo reply contains {L=<any>, E=1} DS Flags, but does not
contain Associated Label Multipath Information. contain Associated Label Multipath Information.
o IP Multipath Information Types {2, 4, 8} sent, and received echo o IP Multipath Information Types {2, 4, 8} sent, and received echo
reply with {L=1, E=0} in DS flags. reply with {L=1, E=0} in DS Flags.
o Multipath Information Type {TBD4} sent, and received echo reply o Multipath Information Type {10} sent, and received echo reply with
with Multipath Information Type other than {TBD4}. Multipath Information Type other than {10}.
9. Responder LSR Procedures 8. Responder LSR Procedures
Common Procedures: Common Procedures:
o The responder LSR receiving an MPLS echo request packet MUST first o The responder LSR receiving an MPLS echo request packet MUST first
determine whether or not the initiating LSR supports this LSP Ping determine whether or not the initiating LSR supports this LSP ping
and Traceroute extension for Entropy Labels. If either of the and traceroute extension for entropy labels. If either of the
following conditions are met, the responder LSR SHOULD determine following conditions are met, the responder LSR SHOULD determine
that the initiating LSR supports this LSP Ping and Traceroute that the initiating LSR supports this LSP ping and traceroute
extension for entropy labels. extension for entropy labels.
1. Received MPLS echo request contains the Multipath Information 1. Received MPLS echo request contains the Multipath Information
Type {TBD4}. Type {10}.
2. Received MPLS echo request contains a Target FEC Stack TLV 2. Received MPLS echo request contains a Target FEC Stack TLV
that includes the entropy label FEC. that includes the entropy label FEC.
If the initiating LSR is determined not to support this LSP Ping If the initiating LSR is determined not to support this LSP ping
and Traceroute extension for entropy labels, then the responder and traceroute extension for entropy labels, then the responder
LSR MUST NOT follow further procedures described in this section. LSR MUST NOT follow further procedures described in this section.
Specifically, MPLS echo reply packets: Specifically, MPLS echo reply packets:
* MUST have the following DS Flags cleared (i.e., not set): "ELI/ * MUST have the following DS Flags cleared (i.e., not set): "ELI/
EL push indicator" and "Label-based load balance indicator". EL push indicator" and "Label-based load balance indicator".
* MUST NOT use Multipath Information Type {TBD4}. * MUST NOT use the Multipath Information Type {10}.
o The responder LSR receiving an MPLS echo request packet with o The responder LSR receiving an MPLS echo request packet with the
Multipath Information Type {TBD4} MUST validate the following Multipath Information Type {10} MUST validate the following
contents. Any deviation MUST result in the responder LSR contents. Any deviation MUST result in the responder LSR
considering the packet as malformed and returning code 1 considering the packet to be malformed and returning code 1
("Malformed echo request received") in the MPLS echo reply packet. ("Malformed echo request received") in the MPLS echo reply packet.
* IP Multipath Information MUST be included. * IP Multipath Information MUST be included.
* Label Multipath Information MAY be included. * Label Multipath Information MAY be included.
* Associated Label Multipath Information MUST be omitted (NULL). * Associated Label Multipath Information MUST be omitted (NULL).
The following subsections describe expected responder LSR procedures The following subsections describe expected responder LSR procedures
when the echo reply is to include DDMAP TLVs, based on the local load when the echo reply is to include DDMAP TLVs, based on the local load
balance technique being employed. In case the responder LSR performs balance technique being employed. In case the responder LSR performs
deviating load balance techniques on a per downstream basis, deviating load balance techniques on a per-downstream basis,
appropriate procedures matched to each downstream load balance appropriate procedures matched to each downstream load balance
technique MUST be followed. technique MUST be followed.
9.1. IP-based Load Balancer & Not Pushing ELI/EL 8.1. IP-Based Load Balancer That Does Not Push ELI/EL
o The responder MUST set {L=0, E=0} in DS flags. o The responder MUST set {L=0, E=0} in DS Flags.
o If Multipath Information Type {2, 4, 8} is received, the responder o If the Multipath Information Type {2, 4, 8} is received, the
MUST comply with [RFC4379] and [RFC6424]. responder MUST comply with [RFC4379] and [RFC6424].
o If Multipath Information Type {9} is received, the responder MUST o If the Multipath Information Type {9} is received, the responder
reply with Multipath Type {0}. MUST reply with Multipath Type {0}.
o If Multipath Information Type {TBD4} is received, the following o If the Multipath Information Type {10} is received, the following
procedures are to be used: procedures are to be used:
* The responder MUST reply with Multipath Information Type * The responder MUST reply with the Multipath Information Type
{TBD4}. {10}.
* The "Label Multipath Information" and "Associated Label * The "Label Multipath Information" and "Associated Label
Multipath Information" sections MUST be omitted (NULL). Multipath Information" sections MUST be omitted (NULL).
* If no matching IP address is found, then the "IPMultipathType" * If no matching IP address is found, then the "IPMultipathType"
field MUST be set to Multipath Information Type {0} and the "IP field MUST be set to the Multipath Information Type {0} and the
Multipath Information" section MUST also be omitted (NULL). "IP Multipath Information" section MUST also be omitted (NULL).
* If at least one matching IP address is found, then the * If at least one matching IP address is found, then the
"IPMultipathType" field MUST be set to appropriate Multipath "IPMultipathType" field MUST be set to the appropriate
Information Type {2, 4, 8} and the "IP Multipath Information" Multipath Information Type {2, 4, 8} and the "IP Multipath
section MUST be included. Information" section MUST be included.
9.2. IP Based Load Balancer & Pushes ELI/EL 8.2. IP-Based Load Balancer That Pushes ELI/EL
o The responder MUST set {L=0, E=1} in DS flags. o The responder MUST set {L=0, E=1} in DS Flags.
o If Multipath Information Type {9} is received, the responder MUST o If the Multipath Information Type {9} is received, the responder
reply with Multipath Type {0}. MUST reply with Multipath Type {0}.
o If Multipath Type {2, 4, 8, TBD4} is received, the following o If the Multipath Type {2, 4, 8, 10} is received, the following
procedures are to be used: procedures are to be used:
* The responder MUST respond with Multipath Type {TBD4}. See * The responder MUST respond with Multipath Type {10}. See
Section 7 for details of Multipath Type {TBD4}. Section 6 for details of Multipath Type {10}.
* The "Label Multipath Information" section MUST be omitted * The "Label Multipath Information" section MUST be omitted
(i.e., it is not there). (i.e., it is not there).
* The IP address set specified in the received IP Multipath * The IP address set specified in the received IP Multipath
Information MUST be used to determine the returned IP/Label Information MUST be used to determine the returned IP/Label
pairs. pairs.
* If the received Multipath Information Type was {TBD4}, the * If the received Multipath Information Type was {10}, the
received "Label Multipath Information" sections MUST NOT be received "Label Multipath Information" sections MUST NOT be
used to determine the associated label portion of the returned used to determine the associated label portion of the returned
IP/Label pairs. IP/Label pairs.
* If no matching IP address is found, then the "IPMultipathType" * If no matching IP address is found, then the "IPMultipathType"
field MUST be set to Multipath Information Type {0} and the "IP field MUST be set to the Multipath Information Type {0} and the
Multipath Information" section MUST be omitted. In addition, "IP Multipath Information" section MUST be omitted. In
the "Assoc Label Multipath Length" MUST be set to 0, and the addition, the "Associated Label Multipath Length" MUST be set
"Associated Label Multipath Information" section MUST also be to 0, and the "Associated Label Multipath Information" section
omitted. MUST also be omitted.
* If at least one matching IP address is found, then the * If at least one matching IP address is found, then the
"IPMultipathType" field MUST be set to appropriate Multipath "IPMultipathType" field MUST be set to the appropriate
Information Type {2, 4, 8} and the "IP Multipath Information" Multipath Information Type {2, 4, 8} and the "IP Multipath
section MUST be included. In addition, the "Associated Label Information" section MUST be included. In addition, the
Multipath Information" section MUST be populated with a list of "Associated Label Multipath Information" section MUST be
labels corresponding to each IP address specified in the "IP populated with a list of labels corresponding to each IP
Multipath Information" section. "Assoc Label Multipath Length" address specified in the "IP Multipath Information" section.
MUST be set to a value representing the length in octets of the "Associated Label Multipath Length" MUST be set to a value
"Associated Label Multipath Information" field. representing the length in octets of the "Associated Label
Multipath Information" field.
9.3. Label-based Load Balancer & Not Pushing ELI/EL 8.3. Label-Based Load Balancer That Does Not Push ELI/EL
o The responder MUST set {L=1, E=0} in DS flags. o The responder MUST set {L=1, E=0} in DS Flags.
o If Multipath Information Type {2, 4, 8} is received, the responder o If the Multipath Information Type {2, 4, 8} is received, the
MUST reply with Multipath Type {0}. responder MUST reply with Multipath Type {0}.
o If Multipath Information Type {9} is received, the responder MUST o If the Multipath Information Type {9} is received, the responder
comply with [RFC4379] and [RFC6424] as updated by Section 3. MUST comply with [RFC4379] and [RFC6424] as updated by Section 2.
o If Multipath Information Type {TBD4} is received, the following o If the Multipath Information Type {10} is received, the following
procedures are to be used: procedures are to be used:
* The responder MUST reply with Multipath Information Type * The responder MUST reply with the Multipath Information Type
{TBD4}. {10}.
* The "IP Multipath Information" and "Associated Label Multipath * The "IP Multipath Information" and "Associated Label Multipath
Information" sections MUST be omitted (NULL). Information" sections MUST be omitted (NULL).
* If no matching label is found, then the "LbMultipathType" field * If no matching label is found, then the "LbMultipathType" field
MUST be set to Multipath Information Type {0} and the "Label MUST be set to the Multipath Information Type {0} and the
Multipath Information" section MUST also be omitted (NULL). "Label Multipath Information" section MUST also be omitted
(NULL).
* If at least one matching label is found, then the * If at least one matching label is found, then the
"LbMultipathType" field MUST be set to the appropriate "LbMultipathType" field MUST be set to the appropriate
Multipath Information Type {9} and the "Label Multipath Multipath Information Type {9} and the "Label Multipath
Information" section MUST be included. Information" section MUST be included.
9.4. Label-based Load Balancer & Pushes ELI/EL 8.4. Label-Based Load Balancer That Pushes ELI/EL
o The responder MUST set {L=1, E=1} in DS flags. o The responder MUST set {L=1, E=1} in DS Flags.
o If Multipath Information Type {2, 4, 8} is received, the responder o If the Multipath Information Type {2, 4, 8} is received, the
MUST reply with Multipath Type {0}. responder MUST reply with Multipath Type {0}.
o If Multipath Type {9, TBD4} is received, the following procedures o If the Multipath Type {9, 10} is received, the following
are to be used: procedures are to be used:
* The responder MUST respond with Multipath Type {TBD4}. * The responder MUST respond with the Multipath Type {10}.
* The "IP Multipath Information" section MUST be omitted. * The "IP Multipath Information" section MUST be omitted.
* The label set specified in the received Label Multipath * The label set specified in the received Label Multipath
Information MUST be used to determine the returned Label/Label Information MUST be used to determine the returned Label/Label
pairs. pairs.
* If received Multipath Information Type was {TBD4}, received * If the received Multipath Information Type was {10} received,
"Label Multipath Information" sections MUST NOT be used to the "Label Multipath Information" sections MUST NOT be used to
determine the associated label portion of the returned Label/ determine the associated label portion of the returned Label/
Label pairs. Label pairs.
* If no matching label is found, then the "LbMultipathType" field * If no matching label is found, then the "LbMultipathType" field
MUST be set to Multipath Information Type {0} and "Label MUST be set to the Multipath Information Type {0} and the
Multipath Information" section MUST be omitted. In addition, "Label Multipath Information" section MUST be omitted. In
"Assoc Label Multipath Length" MUST be set to 0, and the addition, the "Associated Label Multipath Length" MUST be set
"Associated Label Multipath Information" section MUST also be to 0, and the "Associated Label Multipath Information" section
omitted. MUST also be omitted.
* If at least one matching label is found, then the * If at least one matching label is found, then the
"LbMultipathType" field MUST be set to the appropriate "LbMultipathType" field MUST be set to the appropriate
Multipath Information Type {9} and the "Label Multipath Multipath Information Type {9} and the "Label Multipath
Information" section MUST be included. In addition, the Information" section MUST be included. In addition, the
"Associated Label Multipath Information" section MUST be "Associated Label Multipath Information" section MUST be
populated with a list of labels corresponding to each label populated with a list of labels corresponding to each label
specified in the "Label Multipath Information" section. "Assoc specified in the "Label Multipath Information" section. The
Label Multipath Length" MUST be set to a value representing the "Associated Label Multipath Length" MUST be set to a value
length in octets of the "Associated Label Multipath representing the length in octets of the "Associated Label
Information" field. Multipath Information" field.
9.5. Flow-Aware MS-PW Stitching LSR 8.5. Flow-Aware MS-PW Stitching LSR
A stitching LSR that cross-connects flow-aware Pseudowires behaves in A stitching LSR that cross-connects flow-aware Pseudowires behaves in
one of two ways: one of two ways:
o Load balances on the previous flow label, and carries over the o Load balances on the previous flow label and carries over the same
same flow label. For this case, the stitching LSR is to behave as flow label. For this case, the stitching LSR is to behave as
described in Section 9.3. described in Section 8.3.
o Load balances on the previous flow label, and replaces the flow o Load balances on the previous flow label and replaces the flow
label with a newly computed label. For this case, the stitching label with a newly computed label. For this case, the stitching
LSR is to behave as described in Section 9.4. LSR is to behave as described in Section 8.4.
10. Supported and Unsupported Cases 9. Supported and Unsupported Cases
The MPLS architecture does not define strict rules on how The MPLS architecture does not define strict rules on how
implementations are to identify hash "keys" for load balancing implementations are to identify hash "keys" for load-balancing
purposes. As a result, implementations may be of the following load purposes. As a result, implementations may be of the following load
balancer types: balancer types:
1. IP-based load balancer. 1. IP-based load balancer.
2. Label-based load balancer. 2. Label-based load balancer.
3. Label- and IP-based load balancer. 3. Label- and IP-based load balancer.
For cases (2) and (3), an implementation can include different sets For cases (2) and (3), an implementation can include different sets
of labels from the label stack for load balancing purpose. Thus the of labels from the label stack for load-balancing purpose. Thus, the
following sub-cases are possible: following sub-cases are possible:
a. Entire label stack. a. Entire label stack.
b. Top N labels from label stack where the number of labels in label b. Top N labels from label stack where the number of labels in label
stack is > N. stack is > N.
c. Bottom N labels from label stack where the number of labels in c. Bottom N labels from label stack where the number of labels in
label stack is > N. label stack is > N.
In a scenario where there is one flow label or entropy label present In a scenario where there is one flow label or entropy label present
in the label stack, the following further cases are possible for in the label stack, the following further cases are possible for
(2b), (2c), (3b) and (3c): (2b), (2c), (3b), and (3c):
1. N labels from label stack include flow label or entropy label. 1. N labels from label stack include flow label or entropy label.
2. N labels from label stack do not include flow label or entropy 2. N labels from label stack do not include flow label or entropy
label. label.
Also in a scenario where there are multiple entropy labels present in Also, in a scenario where there are multiple entropy labels present
the label stack, it is possible for implementations to employ in the label stack, it is possible for implementations to employ
deviating techniques: deviating techniques:
o Search for entropy stops at the first entropy label. o Search for entropy stops at the first entropy label.
o Search for entropy includes any entropy label found plus continues o Search for entropy includes any entropy label found plus continues
to search for entropy in the label stack. to search for entropy in the label stack.
Furthermore, handling of reserved (i.e., special) labels varies among Furthermore, handling of reserved (i.e., special) labels varies among
implementations: implementations:
o Reserved labels are used in the hash as any other label would be o Reserved labels are used in the hash as any other label would be
(not a recommended practice.) (not a recommended practice).
o Reserved labels are skipped over and, for implementations limited o Reserved labels are skipped over and, for implementations limited
to N labels, the reserved labels do not count towards the limit of to N labels, the reserved labels do not count towards the limit of
N. N.
o Reserved labels are skipped over and, for implementations limited o Reserved labels are skipped over and, for implementations limited
to N labels, the reserved labels count towards the limit of N. to N labels, the reserved labels count towards the limit of N.
It is important to point this out since the presence of GAL will It is important to point this out since the presence of GAL will
affect those implementations which include reserved labels for load affect those implementations that include reserved labels for load-
balancing purposes. balancing purposes.
As can be seen from the above, there are many types of potential load As can be seen from the above, there are many types of potential
balancing implementations. Attempting for any OAM tools to support load-balancing implementations. Attempting to get any Operations,
ECMP discovery and traversal over all types would require fairly Administration, and Maintenance (OAM) tools to support ECMP discovery
complex procedures. Complexities in OAM tools have minimal benefit and traversal over all types would require fairly complex procedures.
if the majority of implementations are expected to employ only a Complexities in OAM tools have minimal benefit if the majority of
small subset of the cases described above. implementations are expected to employ only a small subset of the
cases described above.
o Section 4.3 of [RFC6790] states that in implementations, for load o Section 4.3 of [RFC6790] states that in implementations, for load-
balancing purposes, parsing beyond the label stack after finding balancing purposes, parsing beyond the label stack after finding
an entropy label has "limited incremental value". Therefore, it an entropy label has "limited incremental value". Therefore, it
is expected that most implementations will be of types "IP-based is expected that most implementations will be of types "IP-based
load balancer" or "Label-based load balancer". load balancer" or "Label-based load balancer".
o Section 2.4.5.1 of [RFC7325] recommends that searching for entropy o Section 2.4.5.1 of [RFC7325] recommends that searching for entropy
labels in the label stack should terminate upon finding the first labels in the label stack should terminate upon finding the first
entropy label. Therefore, it is expected that implementations entropy label. Therefore, it is expected that implementations
will only include the first (top-most) entropy label when there will only include the first (top-most) entropy label when there
are multiple entropy labels in the label stack. are multiple entropy labels in the label stack.
o It is expected that, in most cases, the number of labels in the o It is expected that, in most cases, the number of labels in the
label stack will not exceed the number of labels (N) which label stack will not exceed the number of labels (N) that
implementations can include for load balancing purposes. implementations can include for load-balancing purposes.
o It is expected that labels in the label stack, besides the flow o It is expected that labels in the label stack, besides the flow
label and entropy label, are constant for the lifetime of a single label and entropy label, are constant for the lifetime of a single
LSP multipath traceroute operation. Therefore, deviating load LSP multipath traceroute operation. Therefore, deviating load-
balancing implementations with respect to reserved labels should balancing implementations with respect to reserved labels should
not affect this tool. not affect this tool.
Thus [RFC4379], [RFC6424], and this document support cases (1) and Thus, [RFC4379], [RFC6424], and this document support cases (1) and
(2a1), where only the first (top-most) entropy label is included when (2a1), where only the first (top-most) entropy label is included when
there are multiple entropy labels in the label stack. there are multiple entropy labels in the label stack.
11. Security Considerations 10. Security Considerations
While [RFC4379] and [RFC6424] already allow for the discovery and While [RFC4379] and [RFC6424] already allow for the discovery and
exercise of ECMP paths, this document extends the LSP Ping and exercise of ECMP paths, this document extends the LSP ping and
Traceroute mechanisms to more precisely discover and exercise ECMP traceroute mechanisms to more precisely discover and exercise ECMP
paths when an LSP uses ELI/EL in the label stack. Sourcing or paths when an LSP uses ELI/EL in the label stack. Sourcing or
inspecting LSP Ping packets can be used for network reconnaissance. inspecting LSP ping packets can be used for network reconnaissance.
The extended capability defined in this document requires small The extended capability defined in this document requires minor
additional processing for the responder and initiator nodes. The additional processing for the responder and initiator nodes. The
responder node that pushes ELI/EL will need to compute and return responder node that pushes ELI/EL will need to compute and return
multipath data including associated EL. The initiator node will need multipath data including associated EL. The initiator node will need
to store and handle both IP Multipath and Label Multipath to store and handle both IP Multipath and Label Multipath
Information, and include destination IP addresses and/or ELs in MPLS Information, and include destination IP addresses and/or ELs in MPLS
echo request packets as well as in Multipath Information sent to echo request packets as well as in the Multipath Information sent to
downstream nodes. The security considerations of [RFC4379] already downstream nodes. The security considerations of [RFC4379] already
cover Denial-of-Service attacks by regulating LSP Ping traffic going cover Denial-of-Service attacks by regulating LSP ping traffic going
to the control plane. to the control plane.
Finally, the security measures described in [RFC4379], [RFC6424], and Finally, the security measures described in [RFC4379], [RFC6424], and
[RFC6790] are applicable. [RFC6424] provides guidelines if a network [RFC6790] are applicable. [RFC6424] provides guidelines if a network
operator wants to prevent tracing or does not want to expose details operator wants to prevent tracing or does not want to expose details
of the tunnel and [RFC6790] provides guidance on the use of the EL. of the tunnel and [RFC6790] provides guidance on the use of the EL.
12. IANA Considerations 11. IANA Considerations
12.1. Entropy Label FEC 11.1. Entropy Label FEC
The IANA is requested to assign a new sub-TLV from the "Sub-TLVs for IANA has assigned a new sub-TLV from the "Sub-TLVs for TLV Types 1,
TLV Types 1, 16, and 21" section from the "Multi-Protocol Label 16, and 21" section from the "Multi-Protocol Label Switching (MPLS)
Switching (MPLS) Label Switched Paths (LSPs) Ping Parameters - TLVs" Label Switched Paths (LSPs) Ping Parameters" registry under "TLVs"
registry ([IANA-MPLS-LSP-PING]). ([IANA-MPLS-LSP-PING]).
Sub-Type Sub-TLV Name Reference Sub-Type Sub-TLV Name Reference
-------- ------------ --------- -------- ------------ ---------
TBD1 Entropy label FEC this document 33 Entropy label FEC this document
12.2. DS Flags 11.2. DS Flags
The IANA is requested to assign new bit numbers from the "DS flags" IANA has assigned new bit numbers from the "DS Flags" subregistry
sub-registry from the "Multi-Protocol Label Switching (MPLS) Label from the "TLVs" section of the "Multi-Protocol Label Switching (MPLS)
Switched Paths (LSPs) Ping Parameters - TLVs" registry Label Switched Paths (LSPs) Ping Parameters" registry
([IANA-MPLS-LSP-PING]). ([IANA-MPLS-LSP-PING]).
Note: the "DS flags" sub-registry is created by [RFC7537]. Note: The "DS Flags" subregistry was created by [RFC7537].
Bit number Name Reference Bit number Name Reference
---------- ---------------------------------------- --------- ---------- ---------------------------------------- ---------
TBD2 E: ELI/EL push indicator this document 5 E: ELI/EL push indicator this document
TBD3 L: Label-based load balance indicator this document 4 L: Label-based load balance indicator this document
12.3. Multipath Type 11.3. Multipath Type
The IANA is requested to assign a new value from the "Multipath Type" IANA has assigned a new value from the "Multipath Type" subregistry
sub-registry from the "Multi-Protocol Label Switching (MPLS) Label from the "TLVs" section of the "Multi-Protocol Label Switching (MPLS)
Switched Paths (LSPs) Ping Parameters - TLVs" registry Label Switched Paths (LSPs) Ping Parameters" registry
([IANA-MPLS-LSP-PING]). ([IANA-MPLS-LSP-PING]).
Note: The "Multipath Type" sub-registry is created by [RFC7537]. Note: The "Multipath Type" subregistry was created by [RFC7537].
Value Meaning Reference Value Meaning Reference
---------- ---------------------------------------- --------- ---------- ---------------------------------------- ---------
TBD4 IP and label set this document 10 IP and label set this document
13. Acknowledgements
The authors would like to thank Loa Andersson, Curtis Villamizar,
Daniel King, Sriganesh Kini, Victor Ji, Acee Lindem, Deborah
Brungard, Shawn M Emery, Scott O. Bradner, and Peter Yee for
performing thorough reviews and providing most valuable comments.
Carlos Pignataro would like to acknowledge his lifetime friend Martin
Rigueiro, with deep gratutide and esteem, for sharing his contagious
passion for engineering and sciences, and for selflessly teaching so
many lessons.
14. Contributing Authors
Nagendra Kumar
Cisco Systems, Inc.
Email: naikumar@cisco.com
15. References 12. References
15.1. Normative References 12.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997, DOI 10.17487/RFC2119, March 1997,
<http://www.rfc-editor.org/info/rfc2119>. <http://www.rfc-editor.org/info/rfc2119>.
[RFC4379] Kompella, K. and G. Swallow, "Detecting Multi-Protocol [RFC4379] Kompella, K. and G. Swallow, "Detecting Multi-Protocol
Label Switched (MPLS) Data Plane Failures", RFC 4379, Label Switched (MPLS) Data Plane Failures", RFC 4379,
DOI 10.17487/RFC4379, February 2006, DOI 10.17487/RFC4379, February 2006,
<http://www.rfc-editor.org/info/rfc4379>. <http://www.rfc-editor.org/info/rfc4379>.
skipping to change at page 21, line 25 skipping to change at page 22, line 34
[RFC6790] Kompella, K., Drake, J., Amante, S., Henderickx, W., and [RFC6790] Kompella, K., Drake, J., Amante, S., Henderickx, W., and
L. Yong, "The Use of Entropy Labels in MPLS Forwarding", L. Yong, "The Use of Entropy Labels in MPLS Forwarding",
RFC 6790, DOI 10.17487/RFC6790, November 2012, RFC 6790, DOI 10.17487/RFC6790, November 2012,
<http://www.rfc-editor.org/info/rfc6790>. <http://www.rfc-editor.org/info/rfc6790>.
[RFC7537] Decraene, B., Akiya, N., Pignataro, C., Andersson, L., and [RFC7537] Decraene, B., Akiya, N., Pignataro, C., Andersson, L., and
S. Aldrin, "IANA Registries for LSP Ping Code Points", S. Aldrin, "IANA Registries for LSP Ping Code Points",
RFC 7537, DOI 10.17487/RFC7537, May 2015, RFC 7537, DOI 10.17487/RFC7537, May 2015,
<http://www.rfc-editor.org/info/rfc7537>. <http://www.rfc-editor.org/info/rfc7537>.
15.2. Informative References 12.2. Informative References
[IANA-MPLS-LSP-PING] [IANA-MPLS-LSP-PING]
IANA, "Multi-Protocol Label Switching (MPLS) Label IANA, "Multi-Protocol Label Switching (MPLS) Label
Switched Paths (LSPs) Ping Parameters", Switched Paths (LSPs) Ping Parameters",
<http://www.iana.org/assignments/mpls-lsp-ping-parameters/ <http://www.iana.org/assignments/mpls-lsp-ping-parameters>.
mpls-lsp-ping-parameters.xhtml>.
[RFC6391] Bryant, S., Ed., Filsfils, C., Drafz, U., Kompella, V., [RFC6391] Bryant, S., Ed., Filsfils, C., Drafz, U., Kompella, V.,
Regan, J., and S. Amante, "Flow-Aware Transport of Regan, J., and S. Amante, "Flow-Aware Transport of
Pseudowires over an MPLS Packet Switched Network", Pseudowires over an MPLS Packet Switched Network",
RFC 6391, DOI 10.17487/RFC6391, November 2011, RFC 6391, DOI 10.17487/RFC6391, November 2011,
<http://www.rfc-editor.org/info/rfc6391>. <http://www.rfc-editor.org/info/rfc6391>.
[RFC7325] Villamizar, C., Ed., Kompella, K., Amante, S., Malis, A., [RFC7325] Villamizar, C., Ed., Kompella, K., Amante, S., Malis, A.,
and C. Pignataro, "MPLS Forwarding Compliance and and C. Pignataro, "MPLS Forwarding Compliance and
Performance Requirements", RFC 7325, DOI 10.17487/RFC7325, Performance Requirements", RFC 7325, DOI 10.17487/RFC7325,
August 2014, <http://www.rfc-editor.org/info/rfc7325>. August 2014, <http://www.rfc-editor.org/info/rfc7325>.
Acknowledgements
The authors would like to thank Loa Andersson, Curtis Villamizar,
Daniel King, Sriganesh Kini, Victor Ji, Acee Lindem, Deborah
Brungard, Shawn M Emery, Scott O. Bradner, and Peter Yee for
performing thorough reviews and providing very valuable comments.
Carlos Pignataro would like to acknowledge his lifetime friend Martin
Rigueiro, with deep gratitude and esteem, for sharing his contagious
passion for engineering and sciences, and for selflessly teaching so
many lessons.
Contributors
Nagendra Kumar
Cisco Systems, Inc.
Email: naikumar@cisco.com
Authors' Addresses Authors' Addresses
Nobo Akiya Nobo Akiya
Big Switch Networks Big Switch Networks
Email: nobo.akiya.dev@gmail.com Email: nobo.akiya.dev@gmail.com
George Swallow George Swallow
Cisco Systems, Inc. Cisco Systems, Inc.
Email: swallow@cisco.com Email: swallow@cisco.com
Carlos Pignataro Carlos Pignataro
Cisco Systems, Inc. Cisco Systems, Inc.
Email: cpignata@cisco.com Email: cpignata@cisco.com
Andrew G. Malis Andrew G. Malis
Huawei Technologies Huawei Technologies
Email: agmalis@gmail.com Email: agmalis@gmail.com
Sam Aldrin Sam Aldrin
Google Google
Email: aldrin.ietf@gmail.com Email: aldrin.ietf@gmail.com
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