draft-ietf-isis-te-metric-extensions-11.txt   rfc7810.txt 
Networking Working Group S. Previdi, Ed. Internet Engineering Task Force (IETF) S. Previdi, Ed.
Internet-Draft Cisco Systems, Inc. Request for Comments: 7810 Cisco Systems, Inc.
Intended status: Standards Track S. Giacalone Category: Standards Track S. Giacalone
Expires: August 15, 2016 Unaffiliated ISSN: 2070-1721 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
February 12, 2016 May 2016
IS-IS Traffic Engineering (TE) Metric Extensions IS-IS Traffic Engineering (TE) Metric Extensions
draft-ietf-isis-te-metric-extensions-11
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 data performance criteria (e.g., latency) are becoming as critical to
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 (RFC5305) such that network performance information can be Extensions (RFC 5305) such that network-performance information can
distributed and collected in a scalable fashion. The information be distributed and collected in a scalable fashion. The information
distributed using IS-IS TE Metric Extensions can then be used to make distributed using IS-IS TE Metric Extensions can then be used to make
path selection decisions based on network performance. path-selection decisions based on network performance.
Note that this document only covers the mechanisms with which network
performance information is distributed. The mechanisms for measuring
network performance or acting on that information, once distributed,
are outside the scope of this document.
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].
In this document, these words will appear with that interpretation Note that this document only covers the mechanisms with which
only when in ALL CAPS. Lower case uses of these words are not to be network-performance information is distributed. The mechanisms for
interpreted as carrying RFC-2119 significance. measuring network performance or acting on that information, once
distributed, are outside the scope of this document.
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 5741.
This Internet-Draft will expire on August 15, 2016. 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/rfc7810.
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
Provisions Relating to IETF Documents Provisions Relating to IETF Documents
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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
1.1. Conventions Used in This Document . . . . . . . . . . . . 4
2. TE Metric Extensions to IS-IS . . . . . . . . . . . . . . . . 4 2. TE Metric Extensions to IS-IS . . . . . . . . . . . . . . . . 4
3. Interface and Neighbor Addresses . . . . . . . . . . . . . . 5 3. Interface and Neighbor Addresses . . . . . . . . . . . . . . 5
4. Sub TLV Details . . . . . . . . . . . . . . . . . . . . . . . 6 4. Sub-TLV Details . . . . . . . . . . . . . . . . . . . . . . . 6
4.1. Unidirectional Link Delay Sub-TLV . . . . . . . . . . . . 6 4.1. Unidirectional Link Delay Sub-TLV . . . . . . . . . . . . 6
4.2. Min/Max Unidirectional Link Delay Sub-TLV . . . . . . . . 7 4.2. Min/Max Unidirectional Link Delay Sub-TLV . . . . . . . . 7
4.3. Unidirectional Delay Variation Sub-TLV . . . . . . . . . 8 4.3. Unidirectional Delay Variation Sub-TLV . . . . . . . . . 8
4.4. Unidirectional Link Loss Sub-TLV . . . . . . . . . . . . 8 4.4. Unidirectional Link Loss Sub-TLV . . . . . . . . . . . . 9
4.5. Unidirectional Residual Bandwidth Sub-TLV . . . . . . . . 9 4.5. Unidirectional Residual Bandwidth Sub-TLV . . . . . . . . 10
4.6. Unidirectional Available Bandwidth Sub-TLV . . . . . . . 10 4.6. Unidirectional Available Bandwidth Sub-TLV . . . . . . . 11
4.7. Unidirectional Utilized Bandwidth Sub-TLV . . . . . . . . 11 4.7. Unidirectional Utilized Bandwidth Sub-TLV . . . . . . . . 12
5. Announcement Thresholds and Filters . . . . . . . . . . . . . 12 5. Announcement Thresholds and Filters . . . . . . . . . . . . . 12
6. Announcement Suppression . . . . . . . . . . . . . . . . . . 13 6. Announcement Suppression . . . . . . . . . . . . . . . . . . 13
7. Network Stability and Announcement Periodicity . . . . . . . 13 7. Network Stability and Announcement Periodicity . . . . . . . 14
8. Enabling and Disabling Sub-TLVs . . . . . . . . . . . . . . . 14 8. Enabling and Disabling Sub-TLVs . . . . . . . . . . . . . . . 14
9. Static Metric Override . . . . . . . . . . . . . . . . . . . 14 9. Static Metric Override . . . . . . . . . . . . . . . . . . . 14
10. Compatibility . . . . . . . . . . . . . . . . . . . . . . . . 14 10. Compatibility . . . . . . . . . . . . . . . . . . . . . . . . 14
11. Security Considerations . . . . . . . . . . . . . . . . . . . 14 11. Security Considerations . . . . . . . . . . . . . . . . . . . 15
12. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 15 12. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 15
13. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 15 13. References . . . . . . . . . . . . . . . . . . . . . . . . . 16
14. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 16 13.1. Normative References . . . . . . . . . . . . . . . . . . 16
15. References . . . . . . . . . . . . . . . . . . . . . . . . . 16 13.2. Informative References . . . . . . . . . . . . . . . . . 16
15.1. Normative References . . . . . . . . . . . . . . . . . . 16 Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . 17
15.2. Informative References . . . . . . . . . . . . . . . . . 17 Contributors . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 17 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 18
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 IS-IS Extended Reachability TLV defined in [RFC5305], Extensions") to the IS-IS Extended Reachability TLV defined in
that can be used to distribute network performance information (such [RFC5305], that can be used to distribute network-performance
as link delay, delay variation, packet loss, residual bandwidth, and information (such as link delay, delay variation, packet loss,
available bandwidth). 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 proposed 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), by enhancing Constrained-SPF (CSPF), or bandwidth as well as cost), to enhance Constrained-SPF (CSPF), or for
for other uses such as supplementing the data used by an ALTO server other uses such as supplementing the data used by an ALTO server
[RFC7285]. With respect to CSPF, the data distributed by IS-IS TE [RFC7285]. With respect to CSPF, the data distributed by IS-IS TE
Metric Extensions can be used to setup, fail over, and fail back data Metric Extensions can be used to set up, fail over, and fail back
paths using protocols such as RSVP-TE [RFC3209]. 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 [RFC6375], or acting on it once it performance information, such as described in [RFC6375], or acting on
is distributed are outside the scope of this document. Example it once it is distributed are outside the scope of this document.
mechanisms to measure latency, delay variation, and loss in an MPLS Example mechanisms to measure latency, delay variation, and loss in
network are given in [RFC6374]. While this document does not specify an MPLS network are given in [RFC6374]. While this document does not
how the performance information should be obtained, the measurement specify how the performance information should be obtained, the
of delay SHOULD NOT vary significantly based upon the offered traffic measurement of delay SHOULD NOT vary significantly based upon the
load. Thus, queuing delays SHOULD NOT be included in the delay offered traffic load. Thus, queuing delays SHOULD NOT be included in
measurement. For links such as Forwarding Adjacencies, care must be the delay measurement. For links such as Forwarding Adjacencies,
taken that measurement of the associated delay avoids significant care must be taken that measurement of the associated delay avoids
queuing delay; that could be accomplished in a variety of ways, significant queuing delay; that could be accomplished in a variety of
including either by measuring with a traffic class that experiences ways, including either by measuring with a traffic class that
minimal queuing or by summing the measured link delays of the experiences minimal queuing or by summing the measured link delays of
components of the link's path. the components of the link's path.
1.1. Conventions Used in This Document
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].
In this document, these words will appear with that interpretation
only when in ALL CAPS. Lowercase uses of these words are not to be
interpreted as carrying the significance described in RFC 2119.
2. TE Metric Extensions to IS-IS 2. TE Metric Extensions to IS-IS
This document proposes new IS-IS TE sub-TLVs that can be announced in This document registers new IS-IS TE sub-TLVs that can be announced
TLVs 22, 141, 222, and 223 in order to distribute network performance in the "Sub-TLVs for TLVs 22, 23, 141, 222, and 223" registry in
information. The extensions in this document build on the ones order to distribute network-performance information. The extensions
provided in IS-IS TE [RFC5305] and GMPLS [RFC4203]. in this document build on the ones provided in IS-IS TE [RFC5305] and
GMPLS [RFC4203].
IS-IS Extended Reachability TLV 22 (defined in [RFC5305]), Inter-AS IS-IS Extended Reachability TLV 22 (defined in [RFC5305]), Inter-AS
reachability information TLV 141 (defined in [RFC5316]) and MT-ISIS Reachability Information TLV 141 (defined in [RFC5316]), and MT-ISIS
TLV 222 (defined in [RFC5120]) have nested sub-TLVs which permit the TLV 222 (defined in [RFC5120]) have nested sub-TLVs that permit the
TLVs to be readily extended. This document proposes several TLVs to be readily extended. This document registers several sub-
additional sub-TLVs: TLVs:
Type Value Type Description
---------------------------------------------------- ----------------------------------------------------
33 (Suggested) Unidirectional Link Delay 33 Unidirectional Link Delay
34 (Suggested) Min/Max Unidirectional Link Delay 34 Min/Max Unidirectional Link Delay
35 (Suggested) Unidirectional Delay Variation 35 Unidirectional Delay Variation
36 (Suggested) Unidirectional Packet Loss 36 Unidirectional Link Loss
37 (Suggested) Unidirectional Residual Bandwidth 37 Unidirectional Residual Bandwidth
38 (Suggested) Unidirectional Available Bandwidth 38 Unidirectional Available Bandwidth
39 (Suggested) Unidirectional Bandwidth Utilization 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 A
bit), the sub-TLV describes steady state link performance. This 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 alternative failover paths. verify 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. These sub-TLVs could be
used by the receiving node to determine whether to fail traffic to a used by the receiving node to determine whether to fail traffic to a
backup path, or whether to calculate an entirely new path. From an backup path or whether to calculate an entirely new path. From an
MPLS perspective, the intent of the A bit is to permit LSP ingress MPLS perspective, the intent of the A bit is to permit label switched
nodes to: path ingress nodes to determine whether the link referenced in the
sub-TLV affects any of the label switched paths for which it is
A) Determine whether the link referenced in the sub-TLV affects any ingress. If they are affected, then they can determine whether those
of the LSPs for which it is ingress. If there are, then: label switched paths still meet end-to-end performance objectives.
If not, then the node could conceivably move affected traffic to a
B) Determine whether those LSPs still meet end-to-end performance pre-established protection label switched path or establish a new
objectives. If not, then: label switched path and place the traffic in it.
C) The node could then conceivably move affected traffic to a pre-
established protection LSP or establish a new LSP 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 (reuse threshold), that sub-TLV can be re-advertised with the A bit
Anomalous bit cleared. In this case, a receiving node can cleared. In this case, a receiving node can conceivably do whatever
conceivably do whatever re-optimization (or failback) it wishes to do re-optimization (or failback) it wishes to do (including nothing).
(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 existing IS-IS TE specification [RFC5305], the
bandwidth advertisements defined in this draft MUST be encoded as bandwidth advertisements defined in this document MUST be encoded as
IEEE floating point values. The delay and delay variation IEEE floating-point values. The delay and delay-variation
advertisements defined in this draft 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 one (i.e., the
forward path latency). The format of this sub-TLV is shown in the forward-path latency). 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 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|A| RESERVED | Delay | |A| RESERVED | Delay |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
where:
Figure 1 Figure 1
Type: TBA (suggested value: 33). where:
Length: 4. Type: 33
A-bit. The A-bit represents the Anomalous (A) bit. The A-bit is set Length: 4
A bit: The A bit represents the Anomalous (A) bit. The A bit is set
when the measured value of this parameter exceeds its configured when the measured value of this parameter exceeds its configured
maximum threshold. The A bit is cleared when the measured value maximum threshold. The A bit is cleared when the measured value
falls below its configured reuse threshold. If the A-bit is clear, falls below its configured reuse threshold. If the A bit is clear,
the sub-TLV 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 RESERVED: This field is reserved for future use. It MUST be set to 0
0 when sent and MUST be ignored when received. 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 micro-seconds, encoded as an integer value. configurable interval in microseconds, encoded as an integer value.
When set to the maximum value 16,777,215 (16.777215 sec), then the When set to the maximum value 16,777,215 (16.777215 sec), then the
delay is at least that value and may be larger. 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 one
(i.e. the forward path latency). The format of this sub-TLV is shown (i.e., the forward-path latency). The format of this sub-TLV is
in the following diagram: 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 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
where:
Figure 2 Figure 2
Type: TBA (suggested value: 34). where:
Length: 8. Type: 34
This field represents the Anomalous (A) bit. The A bit is set when Length: 8
one or more measured values exceed a configured maximum threshold.
The A bit is cleared when the measured value falls below its
configured reuse threshold. If the A bit is clear, the sub-TLV
represents steady state link performance.
RESERVED. This field is reserved for future use. It MUST be set to A bit: This field represents the Anomalous (A) bit. The A bit is set
0 when sent and MUST be ignored when received. when one or more measured values exceed a configured maximum
threshold. The A bit is cleared when the measured value falls below
its configured reuse threshold. If the A bit is clear, the sub-TLV
represents steady-state link performance.
Min Delay. This 24-bit field carries minimum measured link delay RESERVED: This field is reserved for future use. It MUST be set to 0
when sent and MUST be ignored when received.
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 an
integer value. 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 an
integer value. 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 the Min and Max delay to be the same value.
When the delay value (Min or Max) is set to maximum value 16,777,215 When the delay value (Min or Max) is set to the maximum value
(16.777215 sec), then the delay is at least that value and may be 16,777,215 (16.777215 sec), then the delay is at least that value and
larger. 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 one (i.e., the forward-path latency). The format of this sub-
TLV is shown in the following diagram: 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 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
where:
Figure 3 Figure 3
Type: TBA (suggested value: 35). where
Length: 4. Type: 35
RESERVED. This field is reserved for future use. It MUST be set to Length: 4
0 when sent and MUST be ignored when received.
Delay Variation. This 24-bit field carries the average link delay RESERVED: This field is reserved for future use. It MUST be set to 0
when sent and MUST be ignored when received.
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 an
integer value. When set to 0, it has not been measured. When set to integer value. When set to 0, it has not been measured. When set to
the maximum value 16,777,215 (16.777215 sec), then the delay is at the maximum value 16,777,215 (16.777215 sec), then the delay is at
least that value and may be larger. 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 one (i.e., the forward-path loss). The format of this sub-TLV is
shown in the following diagram: 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 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
This sub-TLV has a type of TBD3. Figure 4
The length is 4.
where: where:
Type: TBA (suggested value: 36). Type: 36
Length: 4. Length: 4
A-bit. The A-bit represents the Anomalous (A) bit. The A-bit is set A bit: The A bit represents the Anomalous (A) bit. The A bit is set
when the measured value of this parameter exceeds its configured when the measured value of this parameter exceeds its configured
maximum threshold. The A bit is cleared when the measured value maximum threshold. The A bit is cleared when the measured value
falls below its configured reuse threshold. If the A-bit is clear, falls below its configured reuse threshold. If the A bit is clear,
the sub-TLV 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 RESERVED: This field is reserved for future use. It MUST be set to 0
0 when sent and MUST be ignored when received. when sent and MUST be ignored when received.
Link Loss. This 24-bit field carries link packet loss as a Link Loss: This 24-bit field carries link packet loss as a percentage
percentage of the total traffic sent over a configurable interval. of the total traffic sent over a configurable interval. The basic
The basic unit is 0.000003%, where (2^24 - 2) is 50.331642%. This unit is 0.000003%, where (2^24 - 2) is 50.331642%. This value is the
value is the highest packet loss percentage that can be expressed highest packet-loss percentage that can be expressed (the assumption
(the assumption being that precision is more important on high speed being that precision is more important on high-speed links than the
links than the ability to advertise loss rates greater than this, and ability to advertise loss rates greater than this, and that high-
that high speed links with over 50% loss are unusable). Therefore, speed links with over 50% loss are unusable). Therefore, measured
measured values that are larger than the field maximum SHOULD be values that are larger than the field maximum SHOULD be encoded as
encoded as the maximum value. 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 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 | RESERVED | | Type | Length | RESERVED |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Residual Bandwidth | | Residual Bandwidth |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
where: where:
Type: TBA (suggested value: 37). Type: 37
Length: 4. Length: 4
RESERVED. This field is reserved for future use. It MUST be set to RESERVED: This field is reserved for future use. It MUST be set to 0
0 when sent and MUST be ignored when received. when sent and MUST be ignored when received.
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 or
forwarding adjacency, residual bandwidth is defined to be Maximum forwarding adjacency, residual bandwidth is defined to be the Maximum
Bandwidth [RFC5305] minus the bandwidth currently allocated to RSVP- Bandwidth [RFC5305] minus the bandwidth currently allocated to RSVP-
TE LSPs. For a bundled link, residual bandwidth is defined to be the TE label switched paths. For a bundled link, residual bandwidth is
sum of the component link residual bandwidths. 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]. Residual bandwidth 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 be
reserved) and provides per priority remainders. Residual Bandwidth reserved) and provides per-priority remainders. Residual bandwidth
and Unreserved Bandwidth [RFC5305] can be used concurrently, and each and unreserved bandwidth [RFC5305] can be used concurrently and each
has a separate use case (e.g. the former can be used for applications has a separate use case (e.g., the former can be used for
like Weighted ECMP while the latter can be used for call admission applications like Weighted ECMP while the latter can be used for call
control). 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 | RESERVED | | Type | Length | RESERVED |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Available Bandwidth | | Available Bandwidth |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
where: Figure 5
Figure 4 where:
Type: TBA (suggested value: 38). Type: 38
Length: 4. Length: 4
RESERVED. This field is reserved for future use. It MUST be set to RESERVED: This field is reserved for future use. It MUST be set to 0
0 when sent and MUST be ignored when received. when sent and MUST be ignored when received.
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 LSP packets. For a bundled link, available forwarding of non-RSVP-TE label switched path packets. For a bundled
bandwidth is defined to be the sum of the component link available link, available bandwidth is defined to be the sum of the component
bandwidths minus the measured bandwidth used for the actual link available bandwidths minus the measured bandwidth used for the
forwarding of non-RSVP-TE Label Switched Paths packets. For a actual forwarding of non-RSVP-TE label switched path packets. For a
bundled link, available bandwidth is defined to be the sum of the bundled link, available bandwidth is defined to be the sum of the
component 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 | RESERVED | | Type | Length | RESERVED |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Utilized Bandwidth | | Utilized Bandwidth |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
where: Figure 6
Figure 5 where:
Type: TBA (suggested value: 39). Type: 39
Length: 4. Length: 4
RESERVED. This field is reserved for future use. It MUST be set to RESERVED: This field is reserved for future use. It MUST be set to 0
0 when sent and MUST be ignored when received. when sent and MUST be ignored when received.
This field carries the bandwidth utilization on a link, forwarding Utilized Bandwidth: This field carries the bandwidth utilization on a
adjacency, or bundled link in IEEE floating-point format with units link, forwarding adjacency, or bundled link in IEEE floating-point
of bytes per second. For a link or forwarding adjacency, bandwidth format with units of bytes per second. For a link or forwarding
utilization represents the actual utilization of the link (i.e., as adjacency, bandwidth utilization represents the actual utilization of
measured by the advertising node). For a bundled link, bandwidth the link (i.e., as measured by the advertising node). For a bundled
utilization is defined to be the sum of the component link bandwidth link, bandwidth utilization is defined to be the sum of the component
utilizations. 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 min/max delay and
residual bandwidth) MUST represent an average over a period or be residual bandwidth) MUST represent an average over a period or be
obtained by a filter that is reasonably representative of an average. obtained by a filter that is reasonably representative of an average.
For example, a rolling average is one such filter. For example, a rolling average is one such filter.
Min and max delay MUST each be derived in one of the following ways: Min and max delay MUST each be derived in one of the following ways:
by taking the lowest and/or highest measured value over a measurement by taking the lowest and/or highest measured value over a measurement
interval, or by making use of a filter or other technique to obtain a interval or by making use of a filter or other technique to obtain a
reasonable representation of a min and max value representative of reasonable representation of a min and max value representative of
the interval, with compensation for outliers. 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 per sub-TLV configurable accelerated implementations SHOULD provide configurable accelerated advertisement
advertisement thresholds, such that: thresholds per sub-TLV, such that:
1. If the measured parameter falls outside a configured upper 1. If the measured parameter falls outside a configured upper bound
bound for all but the min delay metric (or lower bound for for all but the minimum delay metric (or lower bound for minimum
min delay metric only) and the advertised sub-TLV is not delay metric only) and the advertised sub-TLV is not already
already outside that bound or, outside that bound or,
2. If the difference between the last advertised value and 2. If the difference between the last advertised value and current
current measured value exceed 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 which include an A-bit, an additional 4. For sub-TLVs that include an A bit, an additional threshold
threshold SHOULD be included corresponding to the SHOULD be included corresponding to the threshold for which the
threshold for which the performance is considered performance is considered anomalous (and sub-TLVs with the A bit
anomalous (and sub-TLVs with the A-bit are sent). The are sent). The A bit is cleared when the sub-TLV's performance
A-bit is cleared when the sub-TLV's performance has has been below (or re-crosses) this threshold for an
been below (or re-crosses) this threshold for an advertisement interval(s) to permit fail back.
advertisement interval(s) to permit fail back.
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 supports
both. both.
Additionally, once outside of the bounds of the threshold, any Additionally, once outside the bounds of the threshold, any
readvertisement 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 readvertisement and/or implementations SHOULD suppress sub-TLV re-advertisement and/or
lengthen the period within which they are refreshed. lengthen the period within which they 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
Section 5 and Section 6 provide configurable mechanisms to bound the Sections 5 and 6 provide configurable mechanisms to bound the number
number of re-advertisements. Instability might occur in very large of re-advertisements. Instability might occur in very large networks
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 1 announcement per second. The default value SHOULD be set to 120
seconds. 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
Implementations MUST make it possible to individually enable or Implementations MUST make it possible to individually enable or
disable each sub-TLV based on configuration. disable each sub-TLV based on configuration.
9. Static Metric Override 9. Static Metric Override
Implementations SHOULD permit the static configuration and/or manual Implementations SHOULD permit static configuration and/or manual
override of dynamic measurements for each sub-TLV in order to override of dynamic measurements for each sub-TLV in order to
simplify migration and to mitigate scenarios where dynamic simplify migration and to mitigate scenarios where dynamic
measurements are not possible. measurements are not possible.
10. Compatibility 10. Compatibility
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 subTLVs 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 describe a mechanism in order to ensure network stability Section 7 describes a mechanism to ensure network stability when the
when the new sub-TLVs defined in this document are advertised. new sub-TLVs defined in this document are advertised. Implementation
Implementation SHOULD follow the described guidelines in order to SHOULD follow the described guidelines to mitigate the instability
mitigate the instability risk. risk.
[RFC5304] describes an authentication method for IS-IS LSP that [RFC5304] describes an authentication method for IS-IS Link State
allows cryptographic authentication of IS-IS LSPs. PDUs that allows cryptographic authentication of IS-IS Link State
PDUs.
It is anticipated that in most deployments, IS-IS protocol is used It is anticipated that in most deployments, the IS-IS protocol is
within an infrastructure entirely under control of the same operator. used within an infrastructure entirely under control of the same
However, it is worth to consider that the effect of sending IS-IS operator. However, it is worth considering that the effect of
Traffic Engineering sub-TLVs over insecure links could result in a sending IS-IS Traffic Engineering sub-TLVs over insecure links could
man-in-the-middle attacker delaying real time data to a given site result in a man-in-the-middle attacker delaying real-time data to a
(or destination), which could negatively affect the value of the data given site or destination, which could negatively affect the value of
for that site/destination. The use of LSP cryptographic the data for that site or destination. The use of Link State PDU
authentication allows to mitigate the risk of man-in-the-middle cryptographic authentication allows mitigation the risk of man-in-
attack. the-middle attack.
12. IANA Considerations 12. IANA Considerations
IANA maintains the registry for the sub-TLVs. IS-IS TE Metric IANA maintains the registry for the sub-TLVs. IANA has registered
Extensions will require one new type code per sub-TLV defined in this the following sub-TLVs in the "Sub-TLVs for TLVs 22, 23, 141, 222,
document in the following sub-TLV registry: TLVs 22, 23, 141, 222, and 223" registry:
and 223:
Type Value Type Description
---------------------------------------------------- ----------------------------------------------------
33 (Suggested) Unidirectional Link Delay 33 Unidirectional Link Delay
34 (Suggested) Min/Max Unidirectional Link Delay
35 (Suggested) Unidirectional Delay Variation
36 (Suggested) Unidirectional Packet Loss
37 (Suggested) Unidirectional Residual Bandwidth
38 (Suggested) Unidirectional Available Bandwidth
39 (Suggested) Unidirectional Bandwidth Utilization
13. Contributors
The following people gave a substantial contribution to the content
of this document and should be considered as co-authors:
Alia Atlas
Juniper Networks
US
akatlas@juniper.net 34 Min/Max Unidirectional Link Delay
Clarence Filsfils 35 Unidirectional Delay Variation
Cisco Systems Inc.
Belgium
Email: cfilsfil@cisco.com 36 Unidirectional Link Loss
14. Acknowledgements 37 Unidirectional Residual Bandwidth
The authors would like to recognize Ayman Soliman, Nabil Bitar, David 38 Unidirectional Available Bandwidth
McDysan, Les Ginsberg, 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 recognize Curtis Villamizar for significant comments 39 Unidirectional Utilized Bandwidth
and direct content collaboration.
15. References 13. References
15.1. Normative References 13.1. 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>.
[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,
skipping to change at page 17, line 5 skipping to change at page 16, line 43
[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, <http://www.rfc-editor.org/info/rfc5316>. December 2008, <http://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, <http://www.rfc-editor.org/info/rfc6119>. February 2011, <http://www.rfc-editor.org/info/rfc6119>.
15.2. Informative References 13.2. Informative References
[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,
<http://www.rfc-editor.org/info/rfc3209>. <http://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,
<http://www.rfc-editor.org/info/rfc4203>. <http://www.rfc-editor.org/info/rfc4203>.
skipping to change at page 17, line 33 skipping to change at page 17, line 26
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,
<http://www.rfc-editor.org/info/rfc6375>. <http://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,
<http://www.rfc-editor.org/info/rfc7285>. <http://www.rfc-editor.org/info/rfc7285>.
Acknowledgements
The authors would like to recognize Ayman Soliman, Nabil Bitar, David
McDysan, Les Ginsberg, 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 recognize Curtis Villamizar for significant comments
and direct content collaboration.
Contributors
The following people contributed substantially to the content of this
document and should be considered co-authors:
Alia Atlas
Juniper Networks
United States
Email: akatlas@juniper.net
Clarence Filsfils
Cisco Systems Inc.
Belgium
Email: cfilsfil@cisco.com
Authors' Addresses Authors' Addresses
Stefano Previdi (editor) Stefano Previdi (editor)
Cisco Systems, Inc. Cisco Systems, Inc.
Via Del Serafico 200 Via Del Serafico 200
Rome 00191 Rome 00191
IT Italy
Email: sprevidi@cisco.com Email: sprevidi@cisco.com
Spencer Giacalone Spencer Giacalone
Unaffiliated Microsoft
Email: spencer.giacalone@gmail.com Email: spencer.giacalone@gmail.com
Dave Ward Dave Ward
Cisco Systems, Inc. Cisco Systems, Inc.
3700 Cisco Way 3700 Cisco Way
SAN JOSE, CA 95134 San Jose, CA 95134
US United States
Email: wardd@cisco.com Email: wardd@cisco.com
John Drake John Drake
Juniper Networks Juniper Networks
1194 N. Mathilda Ave. 1194 N. Mathilda Ave.
Sunnyvale, CA 94089 Sunnyvale, CA 94089
USA United States
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: sunseawq@huawei.com
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