Internet Engineering Task Force (IETF) H. Song

Internet Engineering Task Force (IETF) H. Song
Request for Comments: 9326 Futurewei
Category: Standards Track B. Gafni
ISSN: 2070-1721 Nvidia
F. Brockners
Cisco
S. Bhandari
Thoughtspot
T. Mizrahi
Huawei
November 2022

In Situ Operations, Administration, and Maintenance (IOAM) Direct
Exporting

Abstract

In situ Operations, Administration, and Maintenance (IOAM) is used
for recording and collecting operational and telemetry information.
Specifically, IOAM allows telemetry data to be pushed into data
packets while they traverse the network. This document introduces a
new IOAM option type (denoted IOAM-Option-Type) called the "IOAM
Direct Export (DEX) Option-Type". This Option-Type is used as a
trigger for IOAM data to be directly exported or locally aggregated
without being pushed into in-flight data packets. The exporting
method and format are outside the scope of this document.

Status of This Memo

This is an Internet Standards Track document.

This document is a product of the Internet Engineering Task Force
(IETF). It represents the consensus of the IETF community. It has
received public review and has been approved for publication by the
Internet Engineering Steering Group (IESG). Further information on
Internet Standards is available in Section 2 of RFC 7841.

Information about the current status of this document, any errata,
and how to provide feedback on it may be obtained at
https://www.rfc-editor.org/info/rfc9326.

Copyright Notice

Copyright (c) 2022 IETF Trust and the persons identified as the
document authors. All rights reserved.

This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents
(https://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with respect
to this document. Code Components extracted from this document must
include Revised BSD License text as described in Section 4.e of the
Trust Legal Provisions and are provided without warranty as described
in the Revised BSD License.

Table of Contents

1. Introduction
2. Conventions
2.1. Requirements Language
2.2. Terminology
3. The Direct Exporting (DEX) IOAM-Option-Type
3.1. Overview
3.1.1. DEX Packet Selection
3.1.2. Responding to the DEX Trigger
3.2. The DEX Option-Type Format
4. IANA Considerations
4.1. IOAM Type
4.2. IOAM DEX Flags
4.3. IOAM DEX Extension-Flags
5. Performance Considerations
6. Security Considerations
7. References
7.1. Normative References
7.2. Informative References
Appendix A. Notes about the History of This Document
Acknowledgments
Contributors
Authors' Addresses

1. Introduction

IOAM [RFC9197] is used for monitoring traffic in the network and for
incorporating IOAM data fields (denoted IOAM-Data-Fields) into in-
flight data packets.

IOAM makes use of four possible IOAM-Option-Types, defined in
[RFC9197]: Pre-allocated Trace, Incremental Trace, Proof of Transit
(POT), and Edge-to-Edge.

This document defines a new IOAM-Option-Type called the "IOAM Direct
Export (DEX) Option-Type". This Option-Type is used as a trigger for
IOAM nodes to locally aggregate and process IOAM data and/or to
export it to a receiving entity (or entities). Throughout the
document, this functionality is referred to as "collection" and/or
"exporting". In this context, a "receiving entity" is an entity that
resides within the IOAM domain such as a collector, analyzer,
controller, decapsulating node, or software module in one of the IOAM
nodes.

Note that even though the IOAM-Option-Type is called "Direct Export",
it depends on the deployment whether the receipt of a packet with a
DEX Option-Type leads to the creation of another packet. Some
deployments might simply use the packet with the DEX Option-Type to
trigger local processing of Operations, Administration, and
Maintenance (OAM) data. The functionality of this local processing
is not within the scope of this document.

2. Conventions

2.1. Requirements Language

The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in
BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all
capitals, as shown here.

2.2. Terminology

Abbreviations used in this document:

IOAM: In situ Operations, Administration, and Maintenance

OAM: Operations, Administration, and Maintenance [RFC6291]

DEX: Direct Exporting

3. The Direct Exporting (DEX) IOAM-Option-Type

3.1. Overview

The DEX Option-Type is used as a trigger for collecting IOAM data
locally or exporting it to a receiving entity (or entities).
Specifically, the DEX Option-Type can be used as a trigger for
collecting IOAM data by an IOAM node and locally aggregating it;
thus, this aggregated data can be periodically pushed to a receiving
entity or pulled by a receiving entity on-demand.

This Option-Type is incorporated into data packets by an IOAM
encapsulating node and removed by an IOAM decapsulating node, as
illustrated in Figure 1. The Option-Type can be read, but not
modified, by transit nodes. Note that the terms "IOAM encapsulating
node", "IOAM decapsulating node", and "IOAM transit node" are as
defined in [RFC9197].

^
|Exported IOAM data
|
|
|
+--------------+------+-------+--------------+
| | | |
| | | |
User +---+----+ +---+----+ +---+----+ +---+----+
packets |Encapsu-| | Transit| | Transit| |Decapsu-|
--------->|lating |====>| Node |====>| Node |====>|lating |---->
|Node | | A | | B | |Node |
+--------+ +--------+ +--------+ +--------+
Insert DEX Export Export Remove DEX
option and IOAM data IOAM data option and
export data export data

Figure 1: DEX Architecture

The DEX Option-Type is used as a trigger to collect and/or export
IOAM data. The trigger applies to transit nodes, the decapsulating
node, and the encapsulating node:

* An IOAM encapsulating node configured to incorporate the DEX
Option-Type encapsulates the packets (or possibly a subset of the
packets) it forwards with the DEX Option-Type and MAY export and/
or collect the requested IOAM data immediately. Only IOAM
encapsulating nodes are allowed to add the DEX Option-Type to a
packet. An IOAM encapsulating node can generate probe packets
that incorporate the DEX Option-Type. These probe packets can be
generated periodically or on-demand (for example, triggered by the
management plane). The specification of such probe packets is
outside the scope of this document.

* A transit node that processes a packet with the DEX Option-Type
MAY export and/or collect the requested IOAM data.

* An IOAM decapsulating node that processes a packet with the DEX
Option-Type MAY export and/or collect the requested IOAM data and
MUST decapsulate the IOAM header.

As in [RFC9197], the DEX Option-Type can be incorporated into all or
a subset of the traffic that is forwarded by the encapsulating node,
as further discussed in Section 3.1.1. Moreover, IOAM nodes respond
to the DEX trigger by exporting and/or collecting IOAM data either
for all traversing packets that carry the DEX Option-Type or
selectively only for a subset of these packets, as further discussed
in Section 3.1.2.

3.1.1. DEX Packet Selection

If an IOAM encapsulating node incorporates the DEX Option-Type into
all the traffic it forwards, it may lead to an excessive amount of
exported data, which may overload the network and the receiving
entity. Therefore, an IOAM encapsulating node that supports the DEX
Option-Type MUST support the ability to incorporate the DEX Option-
Type selectively into a subset of the packets that are forwarded by
the IOAM encapsulating node.

Various methods of packet selection and sampling have been previously
defined, such as [RFC7014] and [RFC5475]. Similar techniques can be
applied by an IOAM encapsulating node to apply DEX to a subset of the
forwarded traffic.

The subset of traffic that is forwarded or transmitted with a DEX
Option-Type SHOULD NOT exceed 1/N of the interface capacity on any of
the IOAM encapsulating node's interfaces. It is noted that this
requirement applies to the total traffic that incorporates a DEX
Option-Type, including traffic that is forwarded by the IOAM
encapsulating node and probe packets that are generated by the IOAM
encapsulating node. In this context, N is a parameter that can be
configurable by network operators. If there is an upper bound, M, on
the number of IOAM transit nodes in any path in the network, then it
is RECOMMENDED to use an N such that N >> M (i.e., N is much greater
than M). The rationale is that a packet that includes a DEX Option-
Type may trigger an exported packet from each IOAM transit node along
the path for a total of M exported packets. Thus, if N >> M, then
the number of exported packets is significantly lower than the number
of data packets forwarded by the IOAM encapsulating node. If there
is no prior knowledge about the network topology or size, it is
RECOMMENDED to use N>100.

3.1.2. Responding to the DEX Trigger

The DEX Option-Type specifies which IOAM-Data-Fields should be
exported and/or collected, as specified in Section 3.2. As mentioned
above, the data can be locally collected, aggregated, and/or exported
to a receiving entity proactively or on-demand. If IOAM data is
exported, the format and encapsulation of the packet that contains
the exported data is not within the scope of the current document.
For example, the export format can be based on [IOAM-RAWEXPORT].

An IOAM node that performs DEX-triggered exporting MUST support the
ability to limit the rate of the exported packets. The rate of
exported packets SHOULD be limited so that the number of exported
packets is significantly lower than the number of packets that are
forwarded by the device. The exported data rate SHOULD NOT exceed 1/
N of the interface capacity on any of the IOAM node's interfaces. It
is RECOMMENDED to use N>100. Depending on the IOAM node's
architecture considerations, the export rate may be limited to a
lower number in order to avoid loading the IOAM node. An IOAM node
MAY maintain a counter or a set of counters that count the events in
which the IOAM node receives a packet with the DEX Option-Type and
does not collect and/or export data due to the rate limits.

IOAM nodes SHOULD NOT be configured to export packets over a path or
a tunnel that is subject to IOAM direct exporting. Furthermore, IOAM
encapsulating nodes that can identify a packet as an IOAM exported
packet MUST NOT push a DEX Option-Type into such a packet. This
requirement is intended to prevent nested exporting and/or exporting
loops.

A transit or decapsulating IOAM node that receives an unknown IOAM-
Option-Type ignores it (as defined in [RFC9197]); specifically, nodes
that do not support the DEX Option-Type ignore it. As per [RFC9197],
note that a decapsulating node removes the IOAM encapsulation and all
its IOAM-Option-Types. Specifically, this applies to the case where
one of these options is a (possibly unknown) DEX Option-Type. The
ability to skip over a (possibly unknown) DEX Option-Type in the
parsing or in the decapsulation procedure is dependent on the
specific encapsulation, which is outside the scope of this document.
For example, when IOAM is encapsulated in IPv6 [IOAM-IPV6-OPTIONS],
the DEX Option-Type is incorporated either in a Hop-by-Hop options
header or in a Destination options header; thus, it can be skipped
using the length field in the options header.

3.2. The DEX Option-Type Format

The format of the DEX Option-Type is depicted in Figure 2. The
length of the DEX Option-Type is at least 8 octets. The DEX Option-
Type MAY include one or more optional fields. The existence of the
optional fields is indicated by the corresponding flags in the
Extension-Flags field. Two optional fields are defined in this
document: the Flow ID and Sequence Number fields. Every optional
field MUST be exactly 4 octets long. Thus, the Extension-Flags field
explicitly indicates the length of the DEX Option-Type. Defining a
new optional field requires an allocation of a corresponding flag in
the Extension-Flags field, as specified in Section 4.2.

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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Namespace-ID | Flags |Extension-Flags|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IOAM-Trace-Type | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Flow ID (Optional) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sequence Number (Optional) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

Figure 2: DEX Option-Type Format

Namespace-ID:
A 16-bit identifier of the IOAM namespace, as defined in
[RFC9197].

Flags:
An 8-bit field, comprised of 8 1-bit subfields. Flags are
allocated by IANA, as defined in Section 4.2.

Extension-Flags:
An 8-bit field, comprised of 8 1-bit subfields. Extension-Flags
are allocated by IANA, as defined in Section 4.3. Every bit in
the Extension-Flag field that is set to 1 indicates the existence
of a corresponding optional 4-octet field. An IOAM node that
receives a DEX Option-Type with an unknown flag set to 1 MUST
ignore the corresponding optional field.

IOAM-Trace-Type:
A 24-bit identifier that specifies which IOAM-Data-Fields should
be exported. The format of this field is as defined in [RFC9197].
Specifically, the bit that corresponds to the Checksum Complement
IOAM-Data-Field SHOULD be assigned to be zero by the IOAM
encapsulating node and ignored by transit and decapsulating nodes.
The reason for this is that the Checksum Complement is intended
for in-flight packet modifications and is not relevant for direct
exporting.

Reserved:
This field MUST be ignored by the receiver.

Optional fields:
The optional fields, if present, reside after the Reserved field.
The order of the optional fields is according to the order of the
respective bits, starting from the most significant bit, that are
enabled in the Extension-Flags field. Each optional field is 4
octets long.

Flow ID:
An optional 32-bit field representing the flow identifier. If
the actual Flow ID is shorter than 32 bits, it is zero padded
in its most significant bits. The field is set at the
encapsulating node. The Flow ID can be used to correlate the
exported data of the same flow from multiple nodes and from
multiple packets. Flow ID values are expected to be allocated
in a way that avoids collisions. For example, random
assignment of Flow ID values can be subject to collisions,
while centralized allocation can avoid this problem. The
specification of the Flow ID allocation method is not within
the scope of this document.

Sequence Number:
An optional 32-bit sequence number starting from 0 and
incremented by 1 for each packet from the same flow at the
encapsulating node that includes the DEX option. The Sequence
Number, when combined with the Flow ID, provides a convenient
approach to correlate the exported data from the same user
packet.

4. IANA Considerations

4.1. IOAM Type

The "IOAM Option-Type" registry is defined in Section 7.1 of
[RFC9197]. IANA has allocated the following code point from the
"IOAM Option-Type" registry as follows:

Code Point: 4

Name IOAM Direct Export (DEX) Option-Type

Description: Direct exporting

Reference: This document

4.2. IOAM DEX Flags

IANA has created the "IOAM DEX Flags" registry. This registry
includes 8 flag bits. Allocation is based on the "IETF Review"
procedure defined in [RFC8126].

New registration requests MUST use the following template:

Bit: Desired bit to be allocated in the 8-bit Flags field of the DEX
Option-Type.

Description: Brief description of the newly registered bit.

Reference: Reference to the document that defines the new bit.

4.3. IOAM DEX Extension-Flags

IANA has created the "IOAM DEX Extension-Flags" registry. This
registry includes 8 flag bits. Bit 0 (the most significant bit) and
bit 1 in the registry are allocated by this document and described in
Section 3.2. Allocation of the other bits should be performed based
on the "IETF Review" procedure defined in [RFC8126].

Bit 0: "Flow ID [RFC9326]"

Bit 1: "Sequence Number [RFC9326]"

New registration requests MUST use the following template:

Bit: Desired bit to be allocated in the 8-bit Extension-Flags field
of the DEX Option-Type.

Description: Brief description of the newly registered bit.

Reference: Reference to the document that defines the new bit.

5. Performance Considerations

The DEX Option-Type triggers IOAM data to be collected and/or
exported packets to be exported to a receiving entity (or entities).
In some cases, this may impact the receiving entity's performance or
the performance along the paths leading to it.

Therefore, the performance impact of these exported packets is
limited by taking two measures: at the encapsulating nodes by
selective DEX encapsulation (Section 3.1.1) and at the transit nodes
by limiting exporting rate (Section 3.1.2). These two measures
ensure that direct exporting is used at a rate that does not
significantly affect the network bandwidth and does not overload the
receiving entity. Moreover, it is possible to load balance the
exported data among multiple receiving entities, although the
exporting method is not within the scope of this document.

It should be noted that, in some networks, DEX data may be exported
over an out-of-band network in which a large volume of exported
traffic does not compromise user traffic. In this case, an operator
may choose to disable the exporting rate limiting.

6. Security Considerations

The security considerations of IOAM in general are discussed in
[RFC9197]. Specifically, an attacker may try to use the
functionality that is defined in this document to attack the network.

An attacker may attempt to overload network devices by injecting
synthetic packets that include the DEX Option-Type. Similarly, an
on-path attacker may maliciously incorporate the DEX Option-Type into
transit packets or maliciously remove it from packets in which it is
incorporated.

Forcing DEX, either in synthetic packets or in transit packets, may
overload the IOAM nodes and/or the receiving entity (or entities).
Since this mechanism affects multiple devices along the network path,
it potentially amplifies the effect on the network bandwidth, the
storage of the devices that collect the data, and the receiving
entity's load.

The amplification effect of DEX may be worse in wide area networks in
which there are multiple IOAM-Domains. For example, if DEX is used
in IOAM-Domain 1 for exporting IOAM data to a receiving entity, then
the exported packets of IOAM-Domain 1 can be forwarded through IOAM-
Domain 2, in which they are subject to DEX. In turn, the exported
packets of IOAM-Domain 2 may be forwarded through another IOAM domain
(or through IOAM-Domain 1); theoretically, this recursive
amplification may continue infinitely.

In order to mitigate the attacks described above, the following
requirements (Section 3) have been defined:

* Selective DEX (Section 3.1.1) is applied by IOAM encapsulating
nodes in order to limit the potential impact of DEX attacks to a
small fraction of the traffic.

* Rate limiting of exported traffic (Section 3.1.2) is applied by
IOAM nodes in order to prevent overloading attacks and to
significantly limit the scale of amplification attacks.

* IOAM encapsulating nodes are required to avoid pushing the DEX
Option-Type into IOAM exported packets (Section 3.1.2), thus
preventing some of the amplification and export loop scenarios.

Although the exporting method is not within the scope of this
document, any exporting method MUST secure the exported data from the
IOAM node to the receiving entity in order to protect the
confidentiality and guarantee the integrity of the exported data.
Specifically, an IOAM node that performs DEX exporting MUST send the
exported data to a pre-configured trusted receiving entity that is in
the same IOAM-Domain as the exporting IOAM node. Furthermore, an
IOAM node MUST gain explicit consent to export data to a receiving
entity before starting to send exported data.

An attacker may keep track of the information sent in DEX headers as
a means of reconnaissance. This form of recon can be mitigated to
some extent by careful allocation of the Flow ID and Sequence Number
space in a way that does not compromise privacy aspects, such as
customer identities.

The integrity of the DEX Option-Type can be protected through a
mechanism of the encapsulating protocol. While [IOAM-DATA-INTEGRITY]
introduces an integrity protection mechanism that protects the
integrity of IOAM-Data-Fields, the DEX Option-Type does not include
IOAM-Data-Fields; therefore, these integrity protection mechanisms
are not applicable to the DEX Option-Type. As discussed in the
threat analysis of [IOAM-DATA-INTEGRITY], injection or modification
of IOAM-Option-Type headers are threats that are not addressed in
IOAM.

IOAM is assumed to be deployed in a restricted administrative domain,
thus limiting the scope of the threats above and their effect. This
is a fundamental assumption with respect to the security aspects of
IOAM, as further discussed in [RFC9197].

7. References

7.1. Normative References

[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/info/rfc2119>.

[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, <https://www.rfc-editor.org/info/rfc8174>.

[RFC9197] Brockners, F., Ed., Bhandari, S., Ed., and T. Mizrahi,
Ed., "Data Fields for In Situ Operations, Administration,
and Maintenance (IOAM)", RFC 9197, DOI 10.17487/RFC9197,
May 2022, <https://www.rfc-editor.org/info/rfc9197>.

7.2. Informative References

[IOAM-DATA-INTEGRITY]
Brockners, F., Bhandari, S., Mizrahi, T., and J. Iurman,
"Integrity of In-situ OAM Data Fields", Work in Progress,
Internet-Draft, draft-ietf-ippm-ioam-data-integrity-02, 5
July 2022, <https://datatracker.ietf.org/doc/html/draft-
ietf-ippm-ioam-data-integrity-02>.

[IOAM-IPV6-OPTIONS]
Bhandari, S. and F. Brockners, "In-situ OAM IPv6 Options",
Work in Progress, Internet-Draft, draft-ietf-ippm-ioam-
ipv6-options-09, 11 October 2022,
<https://datatracker.ietf.org/doc/html/draft-ietf-ippm-
ioam-ipv6-options-09>.

[IOAM-RAWEXPORT]
Spiegel, M., Brockners, F., Bhandari, S., and R.
Sivakolundu, "In-situ OAM raw data export with IPFIX",
Work in Progress, Internet-Draft, draft-spiegel-ippm-ioam-
rawexport-06, 21 February 2022,
<https://datatracker.ietf.org/doc/html/draft-spiegel-ippm-
ioam-rawexport-06>.

[POSTCARD-BASED-TELEMETRY]
Song, H., Mirsky, G., Filsfils, C., Abdelsalam, A., Zhou,
T., Li, Z., Graf, T., Mishra, G. S., Shin, J., and K. Lee,
"Marking-based Direct Export for On-path Telemetry", Work
in Progress, Internet-Draft, draft-song-ippm-postcard-
based-telemetry-14, 7 September 2022,
<https://datatracker.ietf.org/doc/html/draft-song-ippm-
postcard-based-telemetry-14>.

[RFC5475] Zseby, T., Molina, M., Duffield, N., Niccolini, S., and F.
Raspall, "Sampling and Filtering Techniques for IP Packet
Selection", RFC 5475, DOI 10.17487/RFC5475, March 2009,
<https://www.rfc-editor.org/info/rfc5475>.

[RFC6291] Andersson, L., van Helvoort, H., Bonica, R., Romascanu,
D., and S. Mansfield, "Guidelines for the Use of the "OAM"
Acronym in the IETF", BCP 161, RFC 6291,
DOI 10.17487/RFC6291, June 2011,
<https://www.rfc-editor.org/info/rfc6291>.

[RFC7014] D'Antonio, S., Zseby, T., Henke, C., and L. Peluso, "Flow
Selection Techniques", RFC 7014, DOI 10.17487/RFC7014,
September 2013, <https://www.rfc-editor.org/info/rfc7014>.

[RFC8126] Cotton, M., Leiba, B., and T. Narten, "Guidelines for
Writing an IANA Considerations Section in RFCs", BCP 26,
RFC 8126, DOI 10.17487/RFC8126, June 2017,
<https://www.rfc-editor.org/info/rfc8126>.

[RFC9322] Mizrahi, T., Brockners, F., Bhandari, S., Gafni, B., and
M. Spiegel, "In Situ Operations, Administration, and
Maintanence (IOAM) Loopback and Active Flags", RFC 9322,
DOI 10.17487/RFC9322, November 2022,
<https://www.rfc-editor.org/info/rfc9322>.

Appendix A. Notes about the History of This Document

This document evolved from combining some of the concepts of PBT-I
from [POSTCARD-BASED-TELEMETRY] with immediate exporting from early
versions of [RFC9322].

In order to help correlate and order the exported packets, it is
possible to include the Hop_Lim/Node_ID IOAM-Data-Field in exported
packets. If the IOAM-Trace-Type [RFC9197] has the Hop_Lim/Node_ID
bit set, then exported packets include the Hop_Lim/Node_ID IOAM-Data-
Field, which contains the TTL/Hop Limit value from a lower layer
protocol. An alternative approach was considered during the design
of this document, according to which a 1-octet Hop Count field would
be included in the DEX header (presumably by claiming some space from
the Flags field). The Hop Limit would start from 0 at the
encapsulating node and be incremented by each IOAM transit node that
supports the DEX Option-Type. In this approach, the Hop Count field
value would also be included in the exported packet.

Acknowledgments

The authors thank Martin Duke, Tommy Pauly, Meral Shirazipour, Colin
Perkins, Stephen Farrell, Linda Dunbar, Justin Iurman, Greg Mirsky,
and other members of the IPPM working group for many helpful
comments.

Contributors

The Editors would like to recognize the contributions of the
following individuals to this document.

Tianran Zhou
Huawei
156 Beiqing Rd.
Beijing
100095
China
Email: [email protected]

Zhenbin Li
Huawei
156 Beiqing Rd.
Beijing
100095
China
Email: [email protected]

Ramesh Sivakolundu
Cisco Systems, Inc.
170 West Tasman Dr.
San Jose, CA 95134
United States of America
Email: [email protected]

Authors' Addresses

Haoyu Song
Futurewei
2330 Central Expressway
Santa Clara, 95050
United States of America
Email: [email protected]

Barak Gafni
Nvidia
Suite 100
350 Oakmead Parkway
Sunnyvale, CA 94085
United States of America
Email: [email protected]

Frank Brockners
Cisco Systems, Inc.
Hansaallee 249
40549 Duesseldorf
Germany
Email: [email protected]

Shwetha Bhandari
Thoughtspot
3rd Floor, Indiqube Orion, Garden Layout, HSR Layout
24th Main Rd
Bangalore 560 102
Karnataka
India
Email: [email protected]

Tal Mizrahi
Huawei
8-2 Matam
Haifa 3190501
Israel
Email: [email protected]