draft-ietf-lsr-isis-rfc7810bis-05.txt   rfc8570.txt 
Link State Routing L. Ginsberg, Ed. Internet Engineering Task Force (IETF) L. Ginsberg, Ed.
Internet-Draft Cisco Systems, Inc. Request for Comments: 8570 Cisco Systems, Inc.
Obsoletes: 7810 (if approved) S. Previdi, Ed. Obsoletes: 7810 S. Previdi, Ed.
Intended status: Standards Track Huawei Category: Standards Track Huawei
Expires: June 23, 2019 S. Giacolone ISSN: 2070-1721 S. Giacalone
Microsoft Microsoft
D. Ward D. Ward
Cisco Systems, Inc. Cisco Systems, Inc.
J. Drake J. Drake
Juniper Networks Juniper Networks
Q. Wu Q. Wu
Huawei Huawei
December 20, 2018 March 2019
IS-IS Traffic Engineering (TE) Metric Extensions IS-IS Traffic Engineering (TE) Metric Extensions
draft-ietf-lsr-isis-rfc7810bis-05
Abstract Abstract
In certain networks, such as, but not limited to, financial In certain networks, such as, but not limited to, financial
information networks (e.g., stock market data providers), network- information networks (e.g., stock market data providers), network-
performance criteria (e.g., latency) are becoming as critical to performance criteria (e.g., latency) are becoming as critical to
data-path selection as other metrics. data-path selection as other metrics.
This document describes extensions to IS-IS Traffic Engineering This document describes extensions to IS-IS Traffic Engineering
Extensions (RFC 5305) such that network-performance information can Extensions (RFC 5305). These extensions provide a way to distribute
be distributed and collected in a scalable fashion. The information and collect network-performance information in a scalable fashion.
distributed using IS-IS TE Metric Extensions can then be used to make The information distributed using IS-IS TE Metric Extensions can then
path-selection decisions based on network performance. be used to make path-selection decisions based on network
performance.
Note that this document only covers the mechanisms with which Note that this document only covers the mechanisms with which
network-performance information is distributed. The mechanisms for network-performance information is distributed. The mechanisms for
measuring network performance or acting on that information, once measuring network performance or acting on that information, once
distributed, are outside the scope of this document. distributed, are outside the scope of this document.
This document obsoletes RFC 7810. This document obsoletes RFC 7810.
Requirements Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in BCP
14 [RFC2119] [RFC8174] when, and only when, they appear in all
capitals, as shown here.
Status of This Memo 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 https://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 June 23, 2019. 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/rfc8570.
Copyright Notice Copyright Notice
Copyright (c) 2018 IETF Trust and the persons identified as the Copyright (c) 2019 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
Provisions Relating to IETF Documents Provisions Relating to IETF Documents
(https://trustee.ietf.org/license-info) in effect on the date of (https://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with respect carefully, as they describe your rights and restrictions with respect
to this document. Code Components extracted from this document must to this document. Code Components extracted from this document must
include Simplified BSD License text as described in Section 4.e of include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License. described in the Simplified BSD License.
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 1. Introduction ....................................................3
2. TE Metric Extensions to IS-IS . . . . . . . . . . . . . . . . 4 1.1. Requirements Language ......................................4
3. Interface and Neighbor Addresses . . . . . . . . . . . . . . 5 2. TE Metric Extensions to IS-IS ...................................5
4. Sub-TLV Details . . . . . . . . . . . . . . . . . . . . . . . 6 3. Interface and Neighbor Addresses ................................6
4.1. Unidirectional Link Delay Sub-TLV . . . . . . . . . . . . 6 4. Sub-TLV Details .................................................7
4.2. Min/Max Unidirectional Link Delay Sub-TLV . . . . . . . . 6 4.1. Unidirectional Link Delay Sub-TLV ..........................7
4.3. Unidirectional Delay Variation Sub-TLV . . . . . . . . . 8 4.2. Min/Max Unidirectional Link Delay Sub-TLV ..................8
4.4. Unidirectional Link Loss Sub-TLV . . . . . . . . . . . . 8 4.3. Unidirectional Delay Variation Sub-TLV .....................9
4.5. Unidirectional Residual Bandwidth Sub-TLV . . . . . . . . 9 4.4. Unidirectional Link Loss Sub-TLV ..........................10
4.6. Unidirectional Available Bandwidth Sub-TLV . . . . . . . 10 4.5. Unidirectional Residual Bandwidth Sub-TLV .................11
4.7. Unidirectional Utilized Bandwidth Sub-TLV . . . . . . . . 11 4.6. Unidirectional Available Bandwidth Sub-TLV ................12
5. Announcement Thresholds and Filters . . . . . . . . . . . . . 12 4.7. Unidirectional Utilized Bandwidth Sub-TLV .................13
6. Announcement Suppression . . . . . . . . . . . . . . . . . . 13 5. Announcement Thresholds and Filters ............................13
7. Network Stability and Announcement Periodicity . . . . . . . 13 6. Announcement Suppression .......................................14
8. Enabling and Disabling Sub-TLVs . . . . . . . . . . . . . . . 13 7. Network Stability and Announcement Periodicity .................15
9. Static Metric Override . . . . . . . . . . . . . . . . . . . 14 8. Enabling and Disabling Sub-TLVs ................................15
10. Compatibility . . . . . . . . . . . . . . . . . . . . . . . . 14 9. Static Metric Override .........................................15
11. Security Considerations . . . . . . . . . . . . . . . . . . . 14 10. Compatibility .................................................15
12. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 14 11. Security Considerations .......................................15
13. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 15 12. IANA Considerations ...........................................16
14. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 15 13. References ....................................................17
15. References . . . . . . . . . . . . . . . . . . . . . . . . . 16 13.1. Normative References .....................................17
15.1. Normative References . . . . . . . . . . . . . . . . . . 16 13.2. Informative References ...................................18
15.2. Informative References . . . . . . . . . . . . . . . . . 17 Appendix A. Changes from RFC 7810 .................................19
Appendix A. Changes from RFC 7810 . . . . . . . . . . . . . . . 17 Acknowledgements ..................................................20
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 18 Contributors ......................................................20
Authors' Addresses ................................................21
1. Introduction 1. Introduction
In certain networks, such as, but not limited to, financial In certain networks, such as, but not limited to, financial
information networks (e.g., stock market data providers), network- information networks (e.g., stock market data providers), network-
performance information (e.g., latency) is becoming as critical to performance information (e.g., latency) is becoming as critical to
data-path selection as other metrics. data-path selection as other metrics.
In these networks, extremely large amounts of money rest on the In these networks, extremely large amounts of money rest on the
ability to access market data in "real time" and to predictably make ability to access market data in "real time" and to predictably make
trades faster than the competition. Because of this, using metrics trades faster than the competition. Because of this, using metrics
such as hop count or cost as routing metrics is becoming only such as hop count or cost as routing metrics is becoming only
tangentially important. Rather, it would be beneficial to be able to tangentially important. Rather, it would be beneficial to be able to
make path-selection decisions based on performance data (such as make path-selection decisions based on performance data (such as
latency) in a cost-effective and scalable way. latency) in a cost-effective and scalable way.
This document describes extensions (hereafter called "IS-IS TE Metric This document describes extensions (hereafter called "IS-IS TE Metric
Extensions") to the IS-IS Extended Reachability TLV defined in Extensions") to the Extended IS Reachability TLV defined in
[RFC5305], that can be used to distribute network-performance [RFC5305]; these extensions can be used to distribute network-
information (such as link delay, delay variation, packet loss, performance information (such as link delay, delay variation, packet
residual bandwidth, and available bandwidth). loss, residual bandwidth, and available bandwidth).
The data distributed by the IS-IS TE Metric Extensions proposed in The data distributed by the IS-IS TE Metric Extensions described in
this document is meant to be used as part of the operation of the this document is meant to be used as part of the operation of the
routing protocol (e.g., by replacing cost with latency or considering routing protocol (e.g., by replacing cost with latency or considering
bandwidth as well as cost), to enhance Constrained-SPF (CSPF), or for bandwidth as well as cost), to enhance Constrained Shortest Path
other uses such as supplementing the data used by an ALTO server First (CSPF), or for other uses such as supplementing the data used
[RFC7285]. With respect to CSPF, the data distributed by IS-IS TE by an Application-Layer Traffic Optimization (ALTO) server [RFC7285].
Metric Extensions can be used to set up, fail over, and fail back With respect to CSPF, the data distributed by IS-IS TE Metric
data paths using protocols such as RSVP-TE [RFC3209]. Extensions can be used to set up, fail over, and fail back data paths
using protocols such as RSVP-TE [RFC3209].
Note that the mechanisms described in this document only disseminate Note that the mechanisms described in this document only disseminate
performance information. The methods for initially gathering that performance information. The methods for initially gathering that
performance information, such as described in [RFC6375], or acting on performance information (such as the methods described in [RFC6375])
it once it is distributed are outside the scope of this document. or how to act on the information once it is distributed are outside
Example mechanisms to measure latency, delay variation, and loss in the scope of this document. Example mechanisms to measure latency,
an MPLS network are given in [RFC6374]. While this document does not delay variation, and loss in an MPLS network are given in [RFC6374].
specify how the performance information should be obtained, the While this document does not specify how the performance information
measurement of delay SHOULD NOT vary significantly based upon the should be obtained, the measurement of delay SHOULD NOT vary
offered traffic load. Thus, queuing delays SHOULD NOT be included in significantly based upon the offered traffic load. Thus, queuing
the delay measurement. For links such as Forwarding Adjacencies, delays SHOULD NOT be included in the delay measurement. For links
care must be taken that measurement of the associated delay avoids such as forwarding adjacencies [RFC4206], care must be taken that
significant queuing delay; that could be accomplished in a variety of measurement of the associated delay avoids significant queuing
ways, including either by measuring with a traffic class that delays; that could be accomplished in a variety of ways, including
experiences minimal queuing or by summing the measured link delays of either (1) measuring with a traffic class that experiences minimal
the components of the link's path. queuing or (2) summing the measured link delays of the components of
the link's path.
This document obsoletes [RFC7810].
1.1. Requirements Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in
BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all
capitals, as shown here.
2. TE Metric Extensions to IS-IS 2. TE Metric Extensions to IS-IS
This document registers new IS-IS TE sub-TLVs that can be announced This document registers new IS-IS TE sub-TLVs in the "Sub-TLVs for
in the "Sub-TLVs for TLVs 22, 23, 141, 222, and 223" registry in TLVs 22, 23, 141, 222, and 223" registry. These new sub-TLVs provide
order to distribute network-performance information. The extensions ways to distribute network-performance information. The extensions
in this document build on the ones provided in IS-IS TE [RFC5305] and in this document build on the extensions provided in IS-IS TE
GMPLS [RFC4203]. [RFC5305] and GMPLS [RFC4203].
IS-IS Extended Reachability TLV 22 (defined in [RFC5305]), Inter-AS The Extended IS Reachability TLV (type 22) (defined in [RFC5305]),
Reachability Information TLV 141 (defined in [RFC5316]), and MT-ISIS Inter-AS Reachability TLV (also called "inter-AS reachability
TLV 222 (defined in [RFC5120]) have nested sub-TLVs that permit the information TLV") (type 141) (defined in [RFC5316]), and MT-ISN TLV
TLVs to be readily extended. This document registers several sub- (type 222) (defined in [RFC5120]) have nested sub-TLVs that permit
TLVs: the TLVs to be readily extended. This document registers several
sub-TLVs:
Type Description Type Description
---------------------------------------------------- ----------------------------------------------------
33 Unidirectional Link Delay 33 Unidirectional Link Delay
34 Min/Max Unidirectional Link Delay 34 Min/Max Unidirectional Link Delay
35 Unidirectional Delay Variation 35 Unidirectional Delay Variation
36 Unidirectional Link Loss 36 Unidirectional Link Loss
37 Unidirectional Residual Bandwidth 37 Unidirectional Residual Bandwidth
38 Unidirectional Available Bandwidth 38 Unidirectional Available Bandwidth
39 Unidirectional Utilized Bandwidth 39 Unidirectional Utilized Bandwidth
As can be seen in the list above, the sub-TLVs described in this As can be seen in the list above, the sub-TLVs described in this
document carry different types of network-performance information. document carry different types of network-performance information.
The new sub-TLVs include a bit called the Anomalous (or "A") bit. The new sub-TLVs include a bit called the Anomalous (or "A") bit.
When the A bit is clear (or when the sub-TLV does not include an A When the A bit is clear (or when the sub-TLV does not include an
bit), the sub-TLV describes steady-state link performance. This A bit), the sub-TLV describes steady-state link performance. This
information could conceivably be used to construct a steady-state information could conceivably be used to construct a steady-state
performance topology for initial tunnel-path computation, or to performance topology for initial tunnel-path computation or to verify
verify alternative failover paths. alternative failover paths.
When network performance violates configurable link-local thresholds, When network performance violates configurable link-local thresholds,
a sub-TLV with the A bit set is advertised. These sub-TLVs could be a sub-TLV with the A bit set is advertised. That sub-TLV could be
used by the receiving node to determine whether to fail traffic to a used by the receiving node to determine whether to (1) fail traffic
backup path or whether to calculate an entirely new path. From an to a backup path or (2) calculate an entirely new path. From an MPLS
MPLS perspective, the intent of the A bit is to permit label switched perspective, the intent of the A bit is to permit label switched path
path ingress nodes to determine whether the link referenced in the ingress nodes to determine whether the link referenced in the sub-TLV
sub-TLV affects any of the label switched paths for which it is affects any of the label switched paths for which it is ingress. If
ingress. If they are affected, then they can determine whether those they are affected, then they can determine whether those label
label switched paths still meet end-to-end performance objectives. switched paths still meet end-to-end performance objectives. If not,
If not, then the node could conceivably move affected traffic to a then the node could conceivably move affected traffic to a
pre-established protection label switched path or establish a new pre-established protection label switched path or establish a new
label switched path and place the traffic in it. label switched path and place the traffic in it.
If link performance then improves beyond a configurable minimum value If link performance then improves beyond a configurable minimum value
(reuse threshold), that sub-TLV can be re-advertised with the A bit (reuse threshold), that sub-TLV can be re-advertised with the A bit
cleared. In this case, a receiving node can conceivably do whatever cleared. In this case, a receiving node can conceivably do whatever
re-optimization (or failback) it wishes to do (including nothing). re-optimization (or failback) it wishes to do (including nothing).
Note that when a sub-TLV does not include the A bit, that sub-TLV Note that when a sub-TLV does not include the A bit, that sub-TLV
cannot be used for failover purposes. The A bit was intentionally cannot be used for failover purposes. The A bit was intentionally
omitted from some sub-TLVs to help mitigate oscillations. See omitted from some sub-TLVs to help mitigate oscillations. See
Section 5 for more information. Section 5 for more information.
Consistent with existing IS-IS TE specification [RFC5305], the Consistent with the existing IS-IS TE specification [RFC5305], the
bandwidth advertisements defined in this document MUST be encoded as bandwidth advertisements defined in this document MUST be encoded as
IEEE floating-point values [IEEE754]. The delay and delay-variation IEEE floating-point values [IEEE754]. The delay and delay-variation
advertisements defined in this document MUST be encoded as integer advertisements defined in this document MUST be encoded as integer
values. Delay values MUST be quantified in units of microseconds, values. Delay values MUST be quantified in units of microseconds,
packet loss MUST be quantified as a percentage of packets sent, and packet loss MUST be quantified as a percentage of packets sent, and
bandwidth MUST be sent as bytes per second. All values (except bandwidth MUST be sent as bytes per second. All values (except
residual bandwidth) MUST be calculated as rolling averages where the residual bandwidth) MUST be calculated as rolling averages, where the
averaging period MUST be a configurable period of time. See averaging period MUST be a configurable period of time. See
Section 5 for more information. Section 5 for more information.
3. Interface and Neighbor Addresses 3. Interface and Neighbor Addresses
The use of IS-IS TE Metric Extensions sub-TLVs is not confined to the The use of IS-IS TE Metric Extensions sub-TLVs is not confined to the
TE context. In other words, IS-IS TE Metric Extensions sub-TLVs TE context. In other words, IS-IS TE Metric Extensions sub-TLVs
defined in this document can also be used for computing paths in the defined in this document can also be used for computing paths in the
absence of a TE subsystem. absence of a TE subsystem.
However, as for the TE case, Interface Address and Neighbor Address However, as for the TE case, Interface Address and Neighbor Address
sub-TLVs (IPv4 or IPv6) MUST be present. The encoding is defined in sub-TLVs (IPv4 or IPv6) MUST be present. The encoding is defined in
[RFC5305] for IPv4 and in [RFC6119] for IPv6. [RFC5305] for IPv4 and in [RFC6119] for IPv6.
4. Sub-TLV Details 4. Sub-TLV Details
4.1. Unidirectional Link Delay Sub-TLV 4.1. Unidirectional Link Delay Sub-TLV
This sub-TLV advertises the average link delay between two directly This sub-TLV advertises the average link delay between two directly
connected IS-IS neighbors. The delay advertised by this sub-TLV MUST connected IS-IS neighbors. The delay advertised by this sub-TLV MUST
be the delay from the local neighbor to the remote one (i.e., the be the delay from the local neighbor to the remote neighbor (i.e.,
forward-path latency). The format of this sub-TLV is shown in the the forward-path latency). The format of this sub-TLV is shown in
following diagram: the following diagram:
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | | Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|A| RESERVED | Delay | |A| RESERVED | Delay |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 1 Figure 1
where: where:
Type: 33 Type: 33
Length: 4 Length: 4
A bit: The A bit represents the Anomalous (A) bit. The A bit is set A bit: This field represents the Anomalous (A) bit. The A bit is
when the measured value of this parameter exceeds its configured set when the measured value of this parameter exceeds its
maximum threshold. The A bit is cleared when the measured value configured maximum threshold. The A bit is cleared when the
falls below its configured reuse threshold. If the A bit is clear, measured value falls below its configured reuse threshold. If the
the sub-TLV represents steady-state link performance. A bit is cleared, the sub-TLV represents steady-state link
performance.
RESERVED: This field is reserved for future use. It MUST be set to 0 RESERVED: This field is reserved for future use. It MUST be set
when sent and MUST be ignored when received. to 0 when sent and MUST be ignored when received.
Delay: This 24-bit field carries the average link delay over a Delay: This 24-bit field carries the average link delay over a
configurable interval in microseconds, encoded as an integer value. configurable interval in microseconds, encoded as an integer
When set to the maximum value 16,777,215 (16.777215 sec), then the value. When set to the maximum value 16,777,215
delay is at least that value and may be larger. (16.777215 seconds), then the delay is at least that value and may
be larger.
4.2. Min/Max Unidirectional Link Delay Sub-TLV 4.2. Min/Max Unidirectional Link Delay Sub-TLV
This sub-TLV advertises the minimum and maximum delay values between This sub-TLV advertises the minimum and maximum delay values between
two directly connected IS-IS neighbors. The delay advertised by this two directly connected IS-IS neighbors. The delay advertised by this
sub-TLV MUST be the delay from the local neighbor to the remote one sub-TLV MUST be the delay from the local neighbor to the remote
(i.e., the forward-path latency). The format of this sub-TLV is neighbor (i.e., the forward-path latency). The format of this
shown in the following diagram: sub-TLV is shown in the following diagram:
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | | Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|A| RESERVED | Min Delay | |A| RESERVED | Min Delay |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| RESERVED | Max Delay | | RESERVED | Max Delay |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 2 Figure 2
where: where:
Type: 34 Type: 34
Length: 8 Length: 8
A bit: This field represents the Anomalous (A) bit. The A bit is set A bit: This field represents the Anomalous (A) bit. The A bit is
when one or more measured values exceed a configured maximum set when one or more measured values exceed a configured maximum
threshold. The A bit is cleared when the measured value falls below threshold. The A bit is cleared when the measured value falls
its configured reuse threshold. If the A bit is clear, the sub-TLV below its configured reuse threshold. If the A bit is cleared,
represents steady-state link performance. the sub-TLV represents steady-state link performance.
RESERVED: This field is reserved for future use. It MUST be set to 0 RESERVED: This field is reserved for future use. It MUST be set
when sent and MUST be ignored when received. to 0 when sent and MUST be ignored when received.
Min Delay: This 24-bit field carries the minimum measured link delay Min Delay: This 24-bit field carries the minimum measured link delay
value (in microseconds) over a configurable interval, encoded as an value (in microseconds) over a configurable interval, encoded as
integer value. an integer value.
Max Delay: This 24-bit field carries the maximum measured link delay Max Delay: This 24-bit field carries the maximum measured link delay
value (in microseconds) over a configurable interval, encoded as an value (in microseconds) over a configurable interval, encoded as
integer value. an integer value.
Implementations MAY also permit the configuration of an offset value Implementations MAY also permit the configuration of an offset value
(in microseconds) to be added to the measured delay value, to (in microseconds) to be added to the measured delay value, to
facilitate the communication of operator-specific delay constraints. facilitate the communication of operator-specific delay constraints.
It is possible for the Min and Max delay to be the same value. It is possible for Min Delay and Max Delay to be the same value.
When the delay value (Min or Max) is set to the maximum value When the delay value (Min Delay or Max Delay) is set to the maximum
16,777,215 (16.777215 sec), then the delay is at least that value and value 16,777,215 (16.777215 seconds), then the delay is at least that
may be larger. value and may be larger.
4.3. Unidirectional Delay Variation Sub-TLV 4.3. Unidirectional Delay Variation Sub-TLV
This sub-TLV advertises the average link delay variation between two This sub-TLV advertises the average link delay variation between two
directly connected IS-IS neighbors. The delay variation advertised directly connected IS-IS neighbors. The delay variation advertised
by this sub-TLV MUST be the delay from the local neighbor to the by this sub-TLV MUST be the delay from the local neighbor to the
remote one (i.e., the forward-path latency). The format of this sub- remote neighbor (i.e., the forward-path latency). The format of this
TLV is shown in the following diagram: sub-TLV is shown in the following diagram:
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | | Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| RESERVED | Delay Variation | | RESERVED | Delay Variation |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 3 Figure 3
where where:
Type: 35 Type: 35
Length: 4 Length: 4
RESERVED: This field is reserved for future use. It MUST be set to 0 RESERVED: This field is reserved for future use. It MUST be set
when sent and MUST be ignored when received. to 0 when sent and MUST be ignored when received.
Delay Variation: This 24-bit field carries the average link delay Delay Variation: This 24-bit field carries the average link delay
variation over a configurable interval in microseconds, encoded as an variation over a configurable interval in microseconds, encoded as
integer value. When set to 0, it has not been measured. When set to an integer value. When set to 0, it has not been measured. When
the maximum value 16,777,215 (16.777215 sec), then the delay is at set to the maximum value 16,777,215 (16.777215 seconds), then the
least that value and may be larger. delay is at least that value and may be larger.
4.4. Unidirectional Link Loss Sub-TLV 4.4. Unidirectional Link Loss Sub-TLV
This sub-TLV advertises the loss (as a packet percentage) between two This sub-TLV advertises the loss (as a packet percentage) between two
directly connected IS-IS neighbors. The link loss advertised by this directly connected IS-IS neighbors. The link loss advertised by this
sub-TLV MUST be the packet loss from the local neighbor to the remote sub-TLV MUST be the packet loss from the local neighbor to the remote
one (i.e., the forward-path loss). The format of this sub-TLV is neighbor (i.e., the forward-path loss). The format of this sub-TLV
shown in the following diagram: is shown in the following diagram:
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | | Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|A| RESERVED | Link Loss | |A| RESERVED | Link Loss |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 4 Figure 4
where: where:
Type: 36 Type: 36
Length: 4 Length: 4
A bit: The A bit represents the Anomalous (A) bit. The A bit is set A bit: This field represents the Anomalous (A) bit. The A bit is
when the measured value of this parameter exceeds its configured set when the measured value of this parameter exceeds its
maximum threshold. The A bit is cleared when the measured value configured maximum threshold. The A bit is cleared when the
falls below its configured reuse threshold. If the A bit is clear, measured value falls below its configured reuse threshold. If the
the sub-TLV represents steady-state link performance. A bit is cleared, the sub-TLV represents steady-state link
performance.
RESERVED: This field is reserved for future use. It MUST be set to 0 RESERVED: This field is reserved for future use. It MUST be set
when sent and MUST be ignored when received. to 0 when sent and MUST be ignored when received.
Link Loss: This 24-bit field carries link packet loss as a percentage Link Loss: This 24-bit field carries link packet loss as a
of the total traffic sent over a configurable interval. The basic percentage of the total traffic sent over a configurable interval.
unit is 0.000003%, where (2^24 - 2) is 50.331642%. This value is the The basic unit is 0.000003%, where (2^24 - 2) is 50.331642%. This
highest packet-loss percentage that can be expressed (the assumption value is the highest packet-loss percentage that can be expressed
being that precision is more important on high-speed links than the (the assumptions being that (1) precision is more important on
ability to advertise loss rates greater than this, and that high- high-speed links than the ability to advertise loss rates greater
speed links with over 50% loss are unusable). Therefore, measured than this and (2) high-speed links with over 50% loss are
values that are larger than the field maximum SHOULD be encoded as unusable). Therefore, measured values that are larger than the
the maximum value. field maximum SHOULD be encoded as the maximum value.
4.5. Unidirectional Residual Bandwidth Sub-TLV 4.5. Unidirectional Residual Bandwidth Sub-TLV
This sub-TLV advertises the residual bandwidth between two directly This sub-TLV advertises the residual bandwidth between two directly
connected IS-IS neighbors. The residual bandwidth advertised by this connected IS-IS neighbors. The residual bandwidth advertised by this
sub-TLV MUST be the residual bandwidth from the system originating sub-TLV MUST be the residual bandwidth from the system originating
the Link State Advertisement (LSA) to its neighbor. the Link State Advertisement (LSA) to its neighbor.
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | | Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Residual Bandwidth | | Residual Bandwidth |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 5 Figure 5
where: where:
Type: 37 Type: 37
Length: 4 Length: 4
Residual Bandwidth: This field carries the residual bandwidth on a Residual Bandwidth: This field carries the residual bandwidth on a
link, forwarding adjacency [RFC4206], or bundled link in IEEE link, forwarding adjacency [RFC4206], or bundled link in IEEE
floating-point format with units of bytes per second. For a link or floating-point format with units of bytes per second. For a link
forwarding adjacency, residual bandwidth is defined to be the Maximum or forwarding adjacency, residual bandwidth is defined to be the
Bandwidth [RFC5305] minus the bandwidth currently allocated to RSVP- maximum bandwidth [RFC5305] minus the bandwidth currently
TE label switched paths. For a bundled link, residual bandwidth is allocated to RSVP-TE label switched paths. For a bundled link,
defined to be the sum of the component link residual bandwidths. residual bandwidth is defined to be the sum of the component link
residual bandwidths.
The calculation of residual bandwidth is different than that of The calculation of residual bandwidth is different than that of
unreserved bandwidth [RFC5305]. Residual bandwidth subtracts tunnel unreserved bandwidth [RFC5305]. This calculation subtracts tunnel
reservations from maximum bandwidth (i.e., the link capacity) reservations from maximum bandwidth (i.e., the link capacity)
[RFC5305] and provides an aggregated remainder across priorities. [RFC5305] and provides an aggregated remainder across priorities.
Unreserved bandwidth, on the other hand, is subtracted from the Unreserved bandwidth, on the other hand, is subtracted from the
maximum reservable bandwidth (the bandwidth that can theoretically be maximum reservable bandwidth (the bandwidth that can theoretically
reserved) and provides per-priority remainders. Residual bandwidth be reserved) and provides per-priority remainders. Residual
and unreserved bandwidth [RFC5305] can be used concurrently and each bandwidth and unreserved bandwidth [RFC5305] can be used
has a separate use case (e.g., the former can be used for concurrently, and each has a separate use case (e.g., the former
applications like Weighted ECMP while the latter can be used for call can be used for applications like Weighted ECMP, while the latter
admission control). can be used for call admission control).
4.6. Unidirectional Available Bandwidth Sub-TLV 4.6. Unidirectional Available Bandwidth Sub-TLV
This sub-TLV advertises the available bandwidth between two directly This sub-TLV advertises the available bandwidth between two directly
connected IS-IS neighbors. The available bandwidth advertised by connected IS-IS neighbors. The available bandwidth advertised by
this sub-TLV MUST be the available bandwidth from the system this sub-TLV MUST be the available bandwidth from the system
originating this sub-TLV. The format of this sub-TLV is shown in the originating this sub-TLV. The format of this sub-TLV is shown in the
following diagram: following diagram:
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | | Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Available Bandwidth | | Available Bandwidth |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 6 Figure 6
where: where:
Type: 38 Type: 38
Length: 4 Length: 4
Available Bandwidth: This field carries the available bandwidth on a Available Bandwidth: This field carries the available bandwidth on a
link, forwarding adjacency, or bundled link in IEEE floating-point link, forwarding adjacency, or bundled link in IEEE floating-point
format with units of bytes per second. For a link or forwarding format with units of bytes per second. For a link or forwarding
adjacency, available bandwidth is defined to be residual bandwidth adjacency, available bandwidth is defined to be residual bandwidth
(see Section 4.5) minus the measured bandwidth used for the actual (see Section 4.5) minus the measured bandwidth used for the actual
forwarding of non-RSVP-TE label switched path packets. For a bundled forwarding of non-RSVP-TE label switched path packets. For a
link, available bandwidth is defined to be the sum of the component bundled link, available bandwidth is defined to be the sum of the
link available bandwidths. component link available bandwidths.
4.7. Unidirectional Utilized Bandwidth Sub-TLV 4.7. Unidirectional Utilized Bandwidth Sub-TLV
This sub-TLV advertises the bandwidth utilization between two This sub-TLV advertises the bandwidth utilization between two
directly connected IS-IS neighbors. The bandwidth utilization directly connected IS-IS neighbors. The bandwidth utilization
advertised by this sub-TLV MUST be the bandwidth from the system advertised by this sub-TLV MUST be the bandwidth from the system
originating this sub-TLV. The format of this sub-TLV is shown in the originating this sub-TLV. The format of this sub-TLV is shown in the
following diagram: following diagram:
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | | Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Utilized Bandwidth | | Utilized Bandwidth |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 7 Figure 7
where: where:
Type: 39 Type: 39
Length: 4 Length: 4
Utilized Bandwidth: This field carries the bandwidth utilization on a
link, forwarding adjacency, or bundled link in IEEE floating-point Utilized Bandwidth: This field carries the bandwidth utilization on
format with units of bytes per second. For a link or forwarding a link, forwarding adjacency, or bundled link in IEEE
adjacency, bandwidth utilization represents the actual utilization of floating-point format with units of bytes per second. For a link
the link (i.e., as measured by the advertising node). For a bundled or forwarding adjacency, bandwidth utilization represents the
link, bandwidth utilization is defined to be the sum of the component actual utilization of the link (i.e., as measured by the
link bandwidth utilizations. advertising node). For a bundled link, bandwidth utilization is
defined to be the sum of the component link bandwidth
utilizations.
5. Announcement Thresholds and Filters 5. Announcement Thresholds and Filters
The values advertised in all sub-TLVs (except min/max delay and The values advertised in all sub-TLVs (except minimum/maximum delay
residual bandwidth) MUST represent an average over a period or be and residual bandwidth) MUST represent an average over a period of
obtained by a filter that is reasonably representative of an average. time or be obtained by a filter that is reasonably representative of
For example, a rolling average is one such filter. an average. For example, a rolling average is one such filter.
Min and max delay MUST each be derived in one of the following ways: Minimum and maximum delay MUST each be derived in one of the
by taking the lowest and/or highest measured value over a measurement following ways: by taking the lowest and/or highest measured value
interval or by making use of a filter or other technique to obtain a over a measurement interval or by making use of a filter or other
reasonable representation of a min and max value representative of technique to obtain a reasonable representation of a minimum value
the interval, with compensation for outliers. and a maximum value representative of the interval, with compensation
for outliers.
The measurement interval, any filter coefficients, and any The measurement interval, any filter coefficients, and any
advertisement intervals MUST be configurable per sub-TLV. advertisement intervals MUST be configurable per sub-TLV.
In addition to the measurement intervals governing re-advertisement, In addition to the measurement intervals governing re-advertisement,
implementations SHOULD provide configurable accelerated advertisement implementations SHOULD provide configurable accelerated advertisement
thresholds per sub-TLV, such that: thresholds per sub-TLV, such that:
1. If the measured parameter falls outside a configured upper bound 1. If the measured parameter falls outside a configured upper bound
for all but the minimum delay metric (or lower bound for minimum for all but the minimum delay metric (or lower bound for the
delay metric only) and the advertised sub-TLV is not already minimum delay metric only) and the advertised sub-TLV is not
outside that bound or, already outside that bound, or
2. If the difference between the last advertised value and current 2. If the difference between the last advertised value and current
measured value exceeds a configured threshold then, measured value exceeds a configured threshold, then
3. The advertisement is made immediately. 3. The advertisement is made immediately.
4. For sub-TLVs that include an A bit, an additional threshold 4. For sub-TLVs that include an A bit, an additional threshold
SHOULD be included corresponding to the threshold for which the SHOULD be included corresponding to the threshold for which the
performance is considered anomalous (and sub-TLVs with the A bit performance is considered anomalous (and sub-TLVs with the A bit
are sent). The A bit is cleared when the sub-TLV's performance are sent). The A bit is cleared when the sub-TLV's performance
has been below (or re-crosses) this threshold for an has been below (or re-crosses) this threshold for one or more
advertisement interval(s) to permit fail back. advertisement intervals to permit failback.
To prevent oscillations, only the high threshold or the low threshold To prevent oscillations, only the high threshold or the low threshold
(but not both) may be used to trigger any given sub-TLV that supports (but not both) may be used to trigger any given sub-TLV that
both. supports both.
Additionally, once outside the bounds of the threshold, any re- Additionally, once outside the bounds of the threshold, any
advertisement of a measurement within the bounds would remain re-advertisement of a measurement within the bounds would remain
governed solely by the measurement interval for that sub-TLV. governed solely by the measurement interval for that sub-TLV.
6. Announcement Suppression 6. Announcement Suppression
When link-performance values change by small amounts that fall under When link-performance values change by small amounts that fall under
thresholds that would cause the announcement of a sub-TLV, thresholds that would cause the announcement of a sub-TLV,
implementations SHOULD suppress sub-TLV re-advertisement and/or implementations SHOULD suppress sub-TLV re-advertisement and/or
lengthen the period within which they are refreshed. lengthen the period within which the sub-TLVs are refreshed.
Only the accelerated advertisement threshold mechanism described in Only the accelerated advertisement threshold mechanism described in
Section 5 may shorten the re-advertisement interval. All suppression Section 5 may shorten the re-advertisement interval. All suppression
and re-advertisement interval backoff timer features SHOULD be and re-advertisement interval backoff timer features SHOULD be
configurable. configurable.
7. Network Stability and Announcement Periodicity 7. Network Stability and Announcement Periodicity
Sections 5 and 6 provide configurable mechanisms to bound the number Sections 5 and 6 provide configurable mechanisms to bound the number
of re-advertisements. Instability might occur in very large networks of re-advertisements. Instability might occur in very large networks
if measurement intervals are set low enough to overwhelm the if measurement intervals are set low enough to overwhelm the
processing of flooded information at some of the routers in the processing of flooded information at some of the routers in the
topology. Therefore, care should be taken in setting these values. topology. Therefore, care should be taken in setting these values.
Additionally, the default measurement interval for all sub-TLVs Additionally, the default measurement interval for all sub-TLVs
SHOULD be 30 seconds. SHOULD be 30 seconds.
Announcements MUST also be able to be throttled using configurable Announcements MUST also be able to be throttled using configurable
inter-update throttle timers. The minimum announcement periodicity inter-update throttle timers. The minimum announcement periodicity
is 1 announcement per second. The default value SHOULD be set to 120 is one announcement per second. The default value SHOULD be set to
seconds. 120 seconds.
Implementations SHOULD NOT permit the inter-update timer to be lower Implementations SHOULD NOT permit the inter-update timer to be lower
than the measurement interval. than the measurement interval.
Furthermore, it is RECOMMENDED that any underlying performance- Furthermore, it is RECOMMENDED that any underlying performance-
measurement mechanisms not include any significant buffer delay, any measurement mechanisms not include any significant buffer delay, any
significant buffer-induced delay variation, or any significant loss significant buffer-induced delay variation, or any significant loss
due to buffer overflow or due to active queue management. due to buffer overflow or due to active queue management.
8. Enabling and Disabling Sub-TLVs 8. Enabling and Disabling Sub-TLVs
skipping to change at page 14, line 23 skipping to change at page 15, line 52
As per [RFC5305], unrecognized sub-TLVs should be silently ignored. As per [RFC5305], unrecognized sub-TLVs should be silently ignored.
11. Security Considerations 11. Security Considerations
The sub-TLVs introduced in this document allow an operator to The sub-TLVs introduced in this document allow an operator to
advertise state information of links (bandwidth, delay) that could be advertise state information of links (bandwidth, delay) that could be
sensitive and that an operator may not want to disclose. sensitive and that an operator may not want to disclose.
Section 7 describes a mechanism to ensure network stability when the Section 7 describes a mechanism to ensure network stability when the
new sub-TLVs defined in this document are advertised. Implementation new sub-TLVs defined in this document are advertised.
SHOULD follow the described guidelines to mitigate the instability
risk. Implementations SHOULD follow the described guidelines to mitigate
the risk of instability.
[RFC5304] describes an authentication method for IS-IS Link State [RFC5304] describes an authentication method for IS-IS Link State
PDUs that allows cryptographic authentication of IS-IS Link State PDUs that allows cryptographic authentication of IS-IS Link State
PDUs. PDUs.
It is anticipated that in most deployments, the IS-IS protocol is It is anticipated that in most deployments, the IS-IS protocol is
used within an infrastructure entirely under control of the same used within an infrastructure entirely under the control of the same
operator. However, it is worth considering that the effect of operator. However, it is worth considering that the effect of
sending IS-IS Traffic Engineering sub-TLVs over insecure links could sending IS-IS Traffic Engineering sub-TLVs over insecure links could
result in a man-in-the-middle attacker delaying real-time data to a include a man-in-the-middle attacker delaying real-time data to a
given site or destination, which could negatively affect the value of given site or destination; this could negatively affect the value of
the data for that site or destination. The use of Link State PDU the data for that site or destination. The use of Link State PDU
cryptographic authentication allows mitigation the risk of man-in- cryptographic authentication allows mitigation of the risk of
the-middle attack. man-in-the-middle attacks.
12. IANA Considerations 12. IANA Considerations
IANA maintains the registry for the sub-TLVs. IANA has registered IANA maintains the registry for the sub-TLVs. IANA has registered
the following sub-TLVs in the "Sub-TLVs for TLVs 22, 23, 141, 222, the following sub-TLVs in the "Sub-TLVs for TLVs 22, 23, 141, 222,
and 223" registry: and 223" registry:
Type Description Type Description
---------------------------------------------------- ----------------------------------------------------
33 Unidirectional Link Delay 33 Unidirectional Link Delay
34 Min/Max Unidirectional Link Delay
35 Unidirectional Delay Variation
36 Unidirectional Link Loss
37 Unidirectional Residual Bandwidth
38 Unidirectional Available Bandwidth
39 Unidirectional Utilized Bandwidth
13. Acknowledgements
In [RFC7810] the authors recognized Ayman Soliman, Nabil Bitar, David
McDysan, Edward Crabbe, Don Fedyk, Hannes Gredler, Uma Chunduri,
Alvaro Retana, Brian Weis, and Barry Leiba for their contribution and
review of this document.
The authors also recognized Curtis Villamizar for significant
comments and direct content collaboration.
For this document the authors thank Jeff Haas for identifying and
reporting the incorrect encoding of the bandwidth related sub-TLVs.
14. Contributors 34 Min/Max Unidirectional Link Delay
The following people contributed substantially to the content of this 35 Unidirectional Delay Variation
document and should be considered co-authors:
Alia Atlas 36 Unidirectional Link Loss
Juniper Networks
United States
Email: akatlas@juniper.net 37 Unidirectional Residual Bandwidth
Clarence Filsfils 38 Unidirectional Available Bandwidth
Cisco Systems Inc.
Belgium
Email: cfilsfil@cisco.com 39 Unidirectional Utilized Bandwidth
15. References 13. References
15.1. Normative References 13.1. Normative References
[IEEE754] Institute of Electrical and Electronics Engineers Computer [IEEE754] Institute of Electrical and Electronics Engineers, "IEEE
Society, "IEEE Standard for Floating-Point Arithmetic. Standard for Floating-Point Arithmetic", IEEE
IEEE Std 754-2008", IEEESTD 2008.4610935, Aug 2008. Std 754-2008.
[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,
<https://www.rfc-editor.org/info/rfc2119>. <https://www.rfc-editor.org/info/rfc2119>.
[RFC4206] Kompella, K. and Y. Rekhter, "Label Switched Paths (LSP) [RFC4206] Kompella, K. and Y. Rekhter, "Label Switched Paths (LSP)
Hierarchy with Generalized Multi-Protocol Label Switching Hierarchy with Generalized Multi-Protocol Label Switching
(GMPLS) Traffic Engineering (TE)", RFC 4206, (GMPLS) Traffic Engineering (TE)", RFC 4206,
DOI 10.17487/RFC4206, October 2005, DOI 10.17487/RFC4206, October 2005,
<https://www.rfc-editor.org/info/rfc4206>. <https://www.rfc-editor.org/info/rfc4206>.
[RFC5120] Przygienda, T., Shen, N., and N. Sheth, "M-ISIS: Multi [RFC5120] Przygienda, T., Shen, N., and N. Sheth, "M-ISIS: Multi
Topology (MT) Routing in Intermediate System to Topology (MT) Routing in Intermediate System to
Intermediate Systems (IS-ISs)", RFC 5120, Intermediate Systems (IS-ISs)", RFC 5120,
DOI 10.17487/RFC5120, February 2008, DOI 10.17487/RFC5120, February 2008,
<https://www.rfc-editor.org/info/rfc5120>. <https://www.rfc-editor.org/info/rfc5120>.
[RFC5304] Li, T. and R. Atkinson, "IS-IS Cryptographic [RFC5304] Li, T. and R. Atkinson, "IS-IS Cryptographic
Authentication", RFC 5304, DOI 10.17487/RFC5304, October Authentication", RFC 5304, DOI 10.17487/RFC5304,
2008, <https://www.rfc-editor.org/info/rfc5304>. October 2008, <https://www.rfc-editor.org/info/rfc5304>.
[RFC5305] Li, T. and H. Smit, "IS-IS Extensions for Traffic [RFC5305] Li, T. and H. Smit, "IS-IS Extensions for Traffic
Engineering", RFC 5305, DOI 10.17487/RFC5305, October Engineering", RFC 5305, DOI 10.17487/RFC5305,
2008, <https://www.rfc-editor.org/info/rfc5305>. October 2008, <https://www.rfc-editor.org/info/rfc5305>.
[RFC5316] Chen, M., Zhang, R., and X. Duan, "ISIS Extensions in [RFC5316] Chen, M., Zhang, R., and X. Duan, "ISIS Extensions in
Support of Inter-Autonomous System (AS) MPLS and GMPLS Support of Inter-Autonomous System (AS) MPLS and GMPLS
Traffic Engineering", RFC 5316, DOI 10.17487/RFC5316, Traffic Engineering", RFC 5316, DOI 10.17487/RFC5316,
December 2008, <https://www.rfc-editor.org/info/rfc5316>. December 2008, <https://www.rfc-editor.org/info/rfc5316>.
[RFC6119] Harrison, J., Berger, J., and M. Bartlett, "IPv6 Traffic [RFC6119] Harrison, J., Berger, J., and M. Bartlett, "IPv6 Traffic
Engineering in IS-IS", RFC 6119, DOI 10.17487/RFC6119, Engineering in IS-IS", RFC 6119, DOI 10.17487/RFC6119,
February 2011, <https://www.rfc-editor.org/info/rfc6119>. February 2011, <https://www.rfc-editor.org/info/rfc6119>.
[RFC7471] Giacalone, S., Ward, D., Drake, J., Atlas, A., and S. [RFC7471] Giacalone, S., Ward, D., Drake, J., Atlas, A., and S.
Previdi, "OSPF Traffic Engineering (TE) Metric Previdi, "OSPF Traffic Engineering (TE) Metric
Extensions", RFC 7471, DOI 10.17487/RFC7471, March 2015, Extensions", RFC 7471, DOI 10.17487/RFC7471, March 2015,
<https://www.rfc-editor.org/info/rfc7471>. <https://www.rfc-editor.org/info/rfc7471>.
[RFC7810] Previdi, S., Ed., Giacalone, S., Ward, D., Drake, J., and [RFC7810] Previdi, S., Ed., Giacalone, S., Ward, D., Drake, J., and
Q. Wu, "IS-IS Traffic Engineering (TE) Metric Extensions", Q. Wu, "IS-IS Traffic Engineering (TE) Metric Extensions",
RFC 7810, DOI 10.17487/RFC7810, May 2016, RFC 7810, DOI 10.17487/RFC7810, May 2016,
<https://www.rfc-editor.org/info/rfc7810>. <https://www.rfc-editor.org/info/rfc7810>.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, RFC 2119 Key Words", BCP 14, RFC 8174,
May 2017, <https://www.rfc-editor.org/info/rfc8174>. DOI 10.17487/RFC8174, May 2017,
<https://www.rfc-editor.org/info/rfc8174>.
15.2. Informative References
[I-D.ietf-idr-te-pm-bgp] 13.2. Informative References
Ginsberg, L., Previdi, S., Wu, Q., Tantsura, J., and C.
Filsfils, "BGP-LS Advertisement of IGP Traffic Engineering
Performance Metric Extensions", draft-ietf-idr-te-pm-
bgp-17 (work in progress), December 2018.
[RFC3209] Awduche, D., Berger, L., Gan, D., Li, T., Srinivasan, V., [RFC3209] Awduche, D., Berger, L., Gan, D., Li, T., Srinivasan, V.,
and G. Swallow, "RSVP-TE: Extensions to RSVP for LSP and G. Swallow, "RSVP-TE: Extensions to RSVP for LSP
Tunnels", RFC 3209, DOI 10.17487/RFC3209, December 2001, Tunnels", RFC 3209, DOI 10.17487/RFC3209, December 2001,
<https://www.rfc-editor.org/info/rfc3209>. <https://www.rfc-editor.org/info/rfc3209>.
[RFC4203] Kompella, K., Ed. and Y. Rekhter, Ed., "OSPF Extensions in [RFC4203] Kompella, K., Ed. and Y. Rekhter, Ed., "OSPF Extensions in
Support of Generalized Multi-Protocol Label Switching Support of Generalized Multi-Protocol Label Switching
(GMPLS)", RFC 4203, DOI 10.17487/RFC4203, October 2005, (GMPLS)", RFC 4203, DOI 10.17487/RFC4203, October 2005,
<https://www.rfc-editor.org/info/rfc4203>. <https://www.rfc-editor.org/info/rfc4203>.
skipping to change at page 17, line 48 skipping to change at page 18, line 43
Delay Measurement Profile for MPLS-Based Transport Delay Measurement Profile for MPLS-Based Transport
Networks", RFC 6375, DOI 10.17487/RFC6375, September 2011, Networks", RFC 6375, DOI 10.17487/RFC6375, September 2011,
<https://www.rfc-editor.org/info/rfc6375>. <https://www.rfc-editor.org/info/rfc6375>.
[RFC7285] Alimi, R., Ed., Penno, R., Ed., Yang, Y., Ed., Kiesel, S., [RFC7285] Alimi, R., Ed., Penno, R., Ed., Yang, Y., Ed., Kiesel, S.,
Previdi, S., Roome, W., Shalunov, S., and R. Woundy, Previdi, S., Roome, W., Shalunov, S., and R. Woundy,
"Application-Layer Traffic Optimization (ALTO) Protocol", "Application-Layer Traffic Optimization (ALTO) Protocol",
RFC 7285, DOI 10.17487/RFC7285, September 2014, RFC 7285, DOI 10.17487/RFC7285, September 2014,
<https://www.rfc-editor.org/info/rfc7285>. <https://www.rfc-editor.org/info/rfc7285>.
[RFC8571] Ginsberg, L., Ed., Previdi, S., Wu, Q., Tantsura, J., and
C. Filsfils, "BGP - Link State (BGP-LS) Advertisement of
IGP Traffic Engineering Performance Metric Extensions",
RFC 8571, DOI 10.17487/RFC8571, March 2019,
<https://www.rfc-editor.org/info/rfc8571>.
Appendix A. Changes from RFC 7810 Appendix A. Changes from RFC 7810
Errata ID: 5293 (https://www.rfc-editor.org/ Errata ID 5293 (https://www.rfc-editor.org/errata/eid5293) correctly
errata_search.php?rfc=7810) correctly identified that in [RFC7810] identified that in [RFC7810] the length associated with the following
the length associated with the following sub-TLVs did not match the sub-TLVs did not match the figures associated with each:
figures associated with each:
37 Unidirectional Residual Bandwidth 37 Unidirectional Residual Bandwidth
38 Unidirectional Available Bandwidth 38 Unidirectional Available Bandwidth
39 Unidirectional Utilized Bandwidth 39 Unidirectional Utilized Bandwidth
The length specified was 4 which did not include the RESERVED field The length specified was 4, which did not include the RESERVED field
shown in the figures. Subsequent investigation revealed that some shown in the figures. Subsequent investigation revealed that some
implementations had used the specified length (4) and omitted the implementations had used the specified length (4) and omitted the
RESERVED field while other implementations included the specified RESERVED field while other implementations included the specified
RESERVED field and used a length of 5. RESERVED field and used a length of 5.
Because these different implementation choices are not interoperable, Because these different implementation choices are not interoperable,
it was decided that a bis version should be generated which resolved it was decided that a bis version should be generated to resolve this
the ambiguity. ambiguity.
The choice made here is to omit the unused RESERVED field from these The choice made here is to omit the unused RESERVED field from these
sub-TLVs and use the length of 4. This matches the corresponding sub-TLVs and use the length of 4. This matches the corresponding
advertisements specified in the equivalent OSPF specification advertisements specified in the equivalent OSPF TE specification
[RFC7471] and the corresponding BGP-LS specification [RFC7471] and the corresponding BGP - Link State (BGP-LS)
[I-D.ietf-idr-te-pm-bgp]. specification [RFC8571].
Some minor editorial corrections have also been made. Some minor editorial corrections have also been made.
Errata ID: 5486 (https://www.rfc-editor.org/errata/eid5486) Errata ID 5486 (https://www.rfc-editor.org/errata/eid5486) identified
identified that in [RFC7810] Section 4.6 the definition of available that in Section 4.6 of [RFC7810] the definition of available
bandwidth on bundled links used a circular definition i.e., it used bandwidth on bundled links used a circular definition, i.e., it used
"sum of the component link available bandwidths" when it should have "sum of the component link available bandwidths" when it should have
used "sum of the component link residual bandwidths". This has been used "sum of the component link residual bandwidths". This has been
corrected and clarified. corrected and clarified.
Acknowledgements
In [RFC7810], the authors recognized Ayman Soliman, Nabil Bitar,
David McDysan, Edward Crabbe, Don Fedyk, Hannes Gredler, Uma
Chunduri, Alvaro Retana, Brian Weis, and Barry Leiba for their
contributions and reviews of this document.
The authors also recognized Curtis Villamizar for significant
comments and direct content collaboration.
For this document, the authors thank Jeff Haas for identifying and
reporting the incorrect encoding of the bandwidth-related sub-TLVs.
Contributors
The following people contributed substantially to the content of this
document and should be considered coauthors:
Alia Atlas
Juniper Networks
United States of America
Email: akatlas@juniper.net
Clarence Filsfils
Cisco Systems, Inc.
Belgium
Email: cfilsfil@cisco.com
Authors' Addresses Authors' Addresses
Les Ginsberg (editor) Les Ginsberg (editor)
Cisco Systems, Inc. Cisco Systems, Inc.
Email: ginsberg@cisco.com Email: ginsberg@cisco.com
Stefano Previdi (editor) Stefano Previdi (editor)
Huawei Huawei
Email: stefano@previdi.net Email: stefano@previdi.net
Spencer Giacolone
Spencer Giacalone
Microsoft Microsoft
Email: spencer.giacalone@gmail.com Email: spencer.giacalone@gmail.com
Dave Ward Dave Ward
Cisco Systems, Inc. Cisco Systems, Inc.
Email: wardd@cisco.com Email: wardd@cisco.com
John Drake John Drake
Juniper Networks Juniper Networks
1194 N. Matilda Ace. 1194 N. Mathilda Ave.
Sunnyvale, C 94089 Sunnyvale, CA 94089
United States United States of America
Email: jdrake@juniper.net Email: jdrake@juniper.net
Qin Wu Qin Wu
Huawei Huawei
101 Software Avenue, Yuhua District 101 Software Avenue, Yuhua District
Nanjing, Jiangsu 210012 Nanjing, Jiangsu 210012
China China
Email: sunseawq@huawei.com Email: bill.wu@huawei.com
 End of changes. 108 change blocks. 
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