draft-ietf-ospf-te-metric-extensions-03.txt   draft-ietf-ospf-te-metric-extensions-04.txt 
Network Working Group S. Giacalone Network Working Group S. Giacalone
Internet Draft Thomson Reuters Internet Draft Thomson Reuters
Intended status: Proposed Standard Intended status: Proposed Standard
Expires: August 2013 D. Ward Expires: December 2013 D. Ward
Cisco Systems Cisco Systems
J. Drake J. Drake
Juniper Networks Juniper Networks
A. Atlas A. Atlas
Juniper Networks Juniper Networks
S. Previdi S. Previdi
Cisco Systems Cisco Systems
February 25, 2013 June 3, 2013
OSPF Traffic Engineering (TE) Metric Extensions OSPF Traffic Engineering (TE) Metric Extensions
draft-ietf-ospf-te-metric-extensions-03.txt draft-ietf-ospf-te-metric-extensions-04.txt
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 data
path selection as other metrics. path selection as other metrics.
This document describes extensions to OSPF TE [RFC3630] such that This document describes extensions to OSPF TE [RFC3630] such that
network performance information can be distributed and collected in a network performance information can be distributed and collected in a
skipping to change at page 2, line 21 skipping to change at page 2, line 21
and may be updated, replaced, or obsoleted by other documents at any and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress." material or to cite them other than as "work in progress."
The list of current Internet-Drafts can be accessed at The list of current Internet-Drafts can be accessed at
http://www.ietf.org/ietf/1id-abstracts.txt http://www.ietf.org/ietf/1id-abstracts.txt
The list of Internet-Draft Shadow Directories can be accessed at The list of Internet-Draft Shadow Directories can be accessed at
http://www.ietf.org/shadow.html http://www.ietf.org/shadow.html
This Internet-Draft will expire on August 25, 2013. This Internet-Draft will expire on December 3, 2013.
Copyright Notice Copyright Notice
Copyright (c) 2012 IETF Trust and the persons identified as the Copyright (c) 2013 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
(http://trustee.ietf.org/license-info) in effect on the date of (http://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...................................................4
2. Conventions used in this document..............................4 2. Conventions used in this document..............................5
3. TE Metric Extensions to OSPF TE................................5 3. TE Metric Extensions to OSPF TE................................5
4. Sub TLV Details................................................6 4. Sub TLV Details................................................7
4.1. Unidirectional Link Delay Sub-TLV.........................6 4.1. Unidirectional Link Delay Sub-TLV.........................7
4.1.1. Type.................................................7 4.1.1. Type.................................................7
4.1.2. Length...............................................7 4.1.2. Length...............................................7
4.1.3. A bit................................................7 4.1.3. A bit................................................7
4.1.4. Reserved.............................................7 4.1.4. Reserved.............................................7
4.1.5. Delay Value..........................................7 4.1.5. Delay Value..........................................7
4.2. Unidirectional Delay Variation Sub-TLV....................7 4.2. Min/Max Unidirectional Link Delay Sub-TLV.................8
4.2.1. Type.................................................8 4.2.1. Type.................................................8
4.2.2. Length...............................................8 4.2.2. Length...............................................8
4.2.3. Reserved.............................................8 4.2.3. A bit................................................8
4.2.4. Delay Variation......................................8 4.2.4. Reserved.............................................8
4.3. Unidirectional Link Loss Sub-TLV..........................8 4.2.5. Low Delay............................................9
4.3.1. Type.................................................8 4.2.6. High Delay...........................................9
4.3.2. Length...............................................9 4.2.7. Reserved.............................................9
4.3.3. A bit................................................9 4.3. Unidirectional Delay Variation Sub-TLV....................9
4.3.4. Reserved.............................................9 4.3.1. Type................................................10
4.3.5. Link Loss............................................9 4.3.2. Length..............................................10
4.4. Unidirectional Residual Bandwidth Sub-TLV.................9 4.3.3. Reserved............................................10
4.4.1. Type................................................10 4.3.4. Delay Variation.....................................10
4.4.2. Length..............................................10 4.4. Unidirectional Link Loss Sub-TLV.........................10
4.4.3. Residual Bandwidth..................................10 4.4.1. Type................................................11
4.5. Unidirectional Available Bandwidth Sub-TLV...............10 4.4.2. Length..............................................11
4.4.4. Type................................................11 4.4.3. A bit...............................................11
4.4.5. Length..............................................11 4.4.4. Reserved............................................11
4.4.6. Available Bandwidth.................................11 4.4.5. Link Loss...........................................11
5. Announcement Thresholds and Filters...........................11 4.5. Unidirectional Residual Bandwidth Sub-TLV................11
6. Announcement Suppression......................................12 4.5.1. Type................................................12
7. Network Stability and Announcement Periodicity................12 4.5.2. Length..............................................12
8. Compatibility.................................................12 4.5.3. Residual Bandwidth..................................12
9. Security Considerations.......................................12 4.5. Unidirectional Available Bandwidth Sub-TLV...............13
10. IANA Considerations..........................................12 4.5.4. Type................................................13
11. References...................................................13 4.5.5. Length..............................................13
11.1. Normative References....................................13 4.5.6. Available Bandwidth.................................13
11.2. Informative References..................................13 5. Announcement Thresholds and Filters...........................13
12. Acknowledgments..............................................13 6. Announcement Suppression......................................14
13. Author's Addresses...........................................14 7. Network Stability and Announcement Periodicity................15
8. Enabling and Disabling Sub-TLVs...............................15
9. Static Metric Override........................................15
10. Compatibility................................................16
11. Security Considerations......................................16
12. IANA Considerations..........................................16
13. References...................................................16
13.1. Normative References....................................16
13.2. Informative References..................................16
14. Acknowledgments..............................................17
15. Author's Addresses...........................................17
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
skipping to change at page 4, line 29 skipping to change at page 4, line 41
fail back data paths using protocols such as RSVP-TE [RFC3209]. 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 [RFC6375], or acting on it once it performance information, such as [RFC6375], or acting on it once it
is distributed are outside the scope of this document. Example is distributed are outside the scope of this document. Example
mechanisms to measure latency, delay variation, and loss in an MPLS mechanisms to measure latency, delay variation, and loss in an MPLS
network are given in [RFC6374]. While this document does not network are given in [RFC6374]. While this document does not
specify how the performance information should be obtained, the specify how the performance information should be obtained, the
measurement of delay SHOULD NOT vary significantly based upon the measurement of delay SHOULD NOT vary significantly based upon the
offered traffic load. Thus, queuing delays SHOULD NOT be included offered traffic load. Thus, queuing delays and/or loss SHOULD NOT
in the delay measurement. For links, such as Forwarding be included in any dynamic delay measurement. For links, such as
Adjacencies, care must be taken that measurement of the associated Forwarding Adjacencies, care must be taken that measurement of the
delay avoids significant queuing delay; that could be accomplished associated delay avoids significant queuing delay; that could be
in a variety of ways, including either by measuring with a traffic accomplished in a variety of ways, including either by measuring
class that experiences minimal queuing or by summing the measured with a traffic class that experiences minimal queuing or by summing
link delays of the components of the link's path. the measured link delays of the components of the link's path.
2. Conventions used in this document 2. Conventions used in this document
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC-2119 [RFC2119]. document are to be interpreted as described in RFC-2119 [RFC2119].
In this document, these words will appear with that interpretation In this document, these words will appear with that interpretation
only when in ALL CAPS. Lower case uses of these words are not to be only when in ALL CAPS. Lower case uses of these words are not to be
interpreted as carrying RFC-2119 significance. interpreted as carrying RFC-2119 significance.
skipping to change at page 5, line 23 skipping to change at page 5, line 33
scope. Each TLV has one or more nested sub-TLVs which permit the TE scope. Each TLV has one or more nested sub-TLVs which permit the TE
LSA to be readily extended. There are two main types of OSPF TE LSA; LSA to be readily extended. There are two main types of OSPF TE LSA;
the Router Address or Link TE LSA. Like the extensions in GMPLS the Router Address or Link TE LSA. Like the extensions in GMPLS
(RFC4203), this document proposes several additional sub-TLVs for (RFC4203), this document proposes several additional sub-TLVs for
the Link TE LSA: the Link TE LSA:
Type Length Value Type Length Value
TBD1 4 Unidirectional Link Delay TBD1 4 Unidirectional Link Delay
TBD2 4 Unidirectional Delay Variation TBD2 8 Low/High Unidirectional Link Delay
TBD3 4 Unidirectional Packet Loss TBD3 4 Unidirectional Delay Variation
TBD4 4 Unidirectional Residual Bandwidth TBD4 4 Unidirectional Packet Loss
TBD5 4 Unidirectional Available Bandwidth TBD5 4 Unidirectional Residual Bandwidth
TBD6 4 Unidirectional Available 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.
Many (but not all) of the sub-TLVs include a bit called the Anomalous Many (but not all) of the sub-TLVs include a bit called the Anomalous
(or "A") bit. When the A bit is clear (or when the sub-TLV does not (or "A") bit. When the A bit is clear (or when the sub-TLV does not
include an A bit), the sub-TLV describes steady state link include an A bit), the sub-TLV describes steady state link
performance. This information could conceivably be used to construct performance. This information could conceivably be used to construct
a steady state performance topology for initial tunnel path a steady state performance topology for initial tunnel path
computation, or to verify alternative failover paths. computation, or to verify alternative failover paths.
skipping to change at page 7, line 30 skipping to change at page 7, line 48
4.1.4. Reserved 4.1.4. Reserved
This field is reserved for future use. It MUST be set to 0 when sent This field is reserved for future use. It MUST be set to 0 when sent
and MUST be ignored when received. and MUST be ignored when received.
4.1.5. Delay Value 4.1.5. Delay Value
This 24-bit field carries the average link delay over a configurable This 24-bit field carries the average link delay over a configurable
interval in micro-seconds, encoded as an integer value. When set to interval in micro-seconds, encoded as an integer value. When set to
0, it has not been measured. When set to the maximum value 16,777,215 the maximum value 16,777,215 (16.777215 sec), then the delay is at
(16.777215 sec), then the delay is at least that value and may be least that value and may be larger. If there is no value to send
larger. (unmeasured and not statically specified), then the sub-TLV should
not be sent or be withdrawn.
4.2. Unidirectional Delay Variation Sub-TLV 4.2. Min/Max Unidirectional Link Delay Sub-TLV
This sub-TLV advertises the minimum and maximum delay values between
two directly connected OSPF neighbors. The delay advertised 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-TLV is shown
in the following diagram:
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| TBD2 | 8 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|A| RESERVED | Min Delay |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| RESERVED | Max Delay |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
4.2.1. Type
This sub-TLV has a type of TBD2.
4.2.2. Length
The length is 8.
4.2.3. A bit
This field represents the Anomalous (A) bit. The A bit is set 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.
4.2.4. Reserved
This field is reserved for future use. It MUST be set to 0 when sent
and MUST be ignored when received.
4.2.5. Low Delay
This 24-bit field carries minimum measured link delay value (in
microseconds) over a configurable interval, encoded as an integer
value.
Implementations MAY also permit the configuration of a static (non
dynamic) offset value (in microseconds) to be added to the measured
delay value, to facilitate the communication of operator specific
delay constraints.
When set to the maximum value 16,777,215 (16.777215 sec), then the
delay is at least that value and may be larger.
4.2.6. High Delay
This 24-bit field carries the maximum measured link delay value (in
microseconds) over a configurable interval, encoded as an integer
value.
Implementations MAY also permit the configuration of a static (non
dynamic) offset value (in microseconds) to be added to the measured
delay value, to facilitate the communication of operator specific
delay constraints.
It is possible for the high delay and low delay to be the same value.
When the delay value is set to maximum value 16,777,215 (16.777215
sec), then the delay is at least that value and may be larger.
4.2.7. Reserved
This field is reserved for future use. It MUST be set to 0 when sent
and MUST be ignored when received.
When only an average delay value is sent, this field is not present
in the 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 OSPF neighbors. The delay variation advertised by directly connected OSPF neighbors. The delay variation advertised by
this sub-TLV MUST be the delay from the local neighbor to the remote 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-TLV is one (i.e. the forward path latency). 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| TBD2 | 4 | | TBD3 | 4 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| RESERVED | Delay Variation | | RESERVED | Delay Variation |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
4.2.1. Type 4.3.1. Type
This sub-TLV has a type of TBD2. This sub-TLV has a type of TBD3.
4.2.2. Length 4.3.2. Length
The length is 4. The length is 4.
4.2.3. Reserved 4.3.3. Reserved
This field is reserved for future use. It MUST be set to 0 when sent This field is reserved for future use. It MUST be set to 0 when sent
and MUST be ignored when received. and MUST be ignored when received.
4.2.4. Delay Variation 4.3.4. Delay Variation
This 24-bit field carries the average link delay variation over a This 24-bit field carries the average link delay variation over a
configurable interval in micro-seconds, encoded as an integer value. configurable interval in micro-seconds, encoded as an integer value.
When set to 0, it has not been measured. When set to the maximum 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 least that value 16,777,215 (16.777215 sec), then the delay is at least that
value and may be larger. value and may be larger.
4.3. 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 OSPF neighbors. The link loss advertised by this directly connected OSPF 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 shown one (i.e. the forward path loss). The format of this sub-TLV is shown
in the following diagram: 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| TBD3 | 4 | | TBD4 | 4 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|A| RESERVED | Link Loss | |A| RESERVED | Link Loss |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
4.3.1. Type 4.4.1. Type
This sub-TLV has a type of TBD3 This sub-TLV has a type of TBD4
4.3.2. Length 4.4.2. Length
The length is 4 The length is 4.
4.3.3. A bit 4.4.3. A bit
This field represents the Anomalous (A) bit. The A bit is set when This field represents the Anomalous (A) bit. The A bit is set when
the measured value of this parameter exceeds its configured maximum the measured value of this parameter exceeds its 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 below
its configured reuse threshold. If the A bit is clear, the sub-TLV its configured reuse threshold. If the A bit is clear, the sub-TLV
represents steady state link performance. represents steady state link performance.
4.3.4. Reserved 4.4.4. Reserved
This field is reserved for future use. It MUST be set to 0 when sent This field is reserved for future use. It MUST be set to 0 when sent
and MUST be ignored when received. and MUST be ignored when received.
4.3.5. Link Loss 4.4.5. Link Loss
This 24-bit field carries link packet loss as a percentage of the This 24-bit field carries link packet loss as a percentage of the
total traffic sent over a configurable interval. The basic unit is total traffic sent over a configurable interval. The basic unit is
0.000003%, where (2^24 - 2) is 50.331642%. This value is the highest 0.000003%, where (2^24 - 2) is 50.331642%. This value is the highest
packet loss percentage that can be expressed (the assumption being packet loss percentage that can be expressed (the assumption being
that precision is more important on high speed links than the ability that precision is more important on high speed links than the ability
to advertise loss rates greater than this, and that high speed links to advertise loss rates greater than this, and that high speed links
with over 50% loss are unusable). Therefore, measured values that are with over 50% loss are unusable). Therefore, measured values that are
larger than the field maximum SHOULD be encoded as the maximum value. larger than the field maximum SHOULD be encoded as the maximum value.
When set to a value of all 1s (2^24 - 1), the link packet loss has When set to a value of all 1s (2^24 - 1), the link packet loss has
not been measured. not been measured.
4.4. Unidirectional Residual Bandwidth Sub-TLV 4.5. Unidirectional Residual Bandwidth Sub-TLV
This TLV advertises the residual bandwidth (defined in section 4.4.3. This TLV advertises the residual bandwidth (defined in section 4.5.3.
between two directly connected OSPF neighbors. The residual bandwidth between two directly connected OSPF neighbors. The residual bandwidth
advertised by this sub-TLV MUST be the residual bandwidth from the advertised by this sub-TLV MUST be the residual bandwidth from the
system originating the LSA to its neighbor. system originating the LSA to its neighbor.
The format of this sub-TLV is shown in the following diagram: The format of this 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| TBD4 | 4 | | TBD5 | 4 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Residual Bandwidth | | Residual Bandwidth |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
4.4.1. Type 4.5.1. Type
This sub-TLV has a type of TBD4. This sub-TLV has a type of TBD5.
4.4.2. Length 4.5.2. Length
The length is 4. The length is 4.
4.4.3. Residual Bandwidth 4.5.3. Residual Bandwidth
This field carries the residual bandwidth on a link, forwarding This field carries the residual bandwidth on a link, forwarding
adjacency [RFC4206], or bundled link in IEEE floating point format adjacency [RFC4206], or bundled link in IEEE floating point format
with units of bytes per second. For a link or forwarding adjacency, with units of bytes per second. For a link or forwarding adjacency,
residual bandwidth is defined to be Maximum Bandwidth [RFC3630] minus residual bandwidth is defined to be Maximum Bandwidth [RFC3630] minus
the bandwidth currently allocated to RSVP-TE LSPs. For a bundled the bandwidth currently allocated to RSVP-TE LSPs. For a bundled
link, residual bandwidth is defined to be the sum of the component link, residual bandwidth is defined to be the sum of the component
link residual bandwidths. link residual bandwidths.
Note that although it may seem possible to calculate Residual The calculation of Residual Bandwidth is different than that of
Bandwidth using the existing sub-TLVs in RFC 3630, this is not a Unreserved Bandwidth [RFC3630]. Residual Bandwidth subtracts tunnel
consistently reliable approach and hence the Residual Bandwidth sub- reservations from Maximum Bandwidth (i.e. the link capacity)
TLV has been added here. For example, because the Maximum Reservable [RFC3630] and provides an aggregated remainder across QoS classes.
Bandwidth [RFC3630] can be larger than the capacity of the link, Unreserved Bandwidth [RFC3630], on the other hand, is subtracted from
using it as part of an algorithm to determine the value of the the Maximum Reservable Bandwidth (the bandwidth that can
Maximum Bandwidth [RFC3630] minus the bandwidth currently allocated theoretically be reserved) [RFC3630] and provides per-QoS-class
to RSVP-TE LSPs cannot be considered reliably accurate. remainders. Residual Bandwidth and Unreserved Bandwidth [RFC3630] can
be used concurrently, and each has a separate use case (e.g. the
former can be used for applications like Weighted ECMP while the
latter can be used for call admission control).
4.5. Unidirectional Available Bandwidth Sub-TLV 4.5. Unidirectional Available Bandwidth Sub-TLV
This TLV advertises the available bandwidth (defined in section This TLV advertises the available bandwidth (defined in section
4.4.6. ) between two directly connected OSPF neighbors. The available 4.5.6. ) between two directly connected OSPF neighbors. The available
bandwidth advertised by this sub-TLV MUST be the available bandwidth bandwidth advertised by this sub-TLV MUST be the available bandwidth
from the system originating the LSA to its neighbor. The format of from the system originating the LSA to its neighbor. The format of
this sub-TLV is shown in the following diagram: this 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| TBD5 | 4 | | TBD6 | 4 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Available Bandwidth | | Available Bandwidth |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
4.4.4. Type 4.5.4. Type
This sub-TLV has a type of TBD5. This sub-TLV has a type of TBD6.
4.4.5. Length 4.5.5. Length
The length is 4. The length is 4.
4.4.6. Available Bandwidth 4.5.6. Available Bandwidth
This field carries the available bandwidth on a link, forwarding This field carries the available bandwidth on a link, forwarding
adjacency, or bundled link in IEEE floating point format with units adjacency, or bundled link in IEEE floating point format with units
of bytes per second. For a link or forwarding adjacency, available of bytes per second. For a link or forwarding adjacency, available
bandwidth is defined to be residual bandwidth (see section 4.4. ) bandwidth is defined to be residual bandwidth (see section 4.5. )
minus the measured bandwidth used for the actual forwarding of non- minus the measured bandwidth used for the actual forwarding of non-
RSVP-TE LSP packets. For a bundled link, available bandwidth is RSVP-TE LSP packets. For a bundled link, available bandwidth is
defined to be the sum of the component link available bandwidths. defined to be the sum of the component link available bandwidths.
5. Announcement Thresholds and Filters 5. Announcement Thresholds and Filters
The values advertised in all sub-TLVs MUST be controlled using an The values advertised in all sub-TLVs (except min/max delay and
exponential filter (i.e. a rolling average) with a configurable residual bandwidth) MUST represent an average over a period or be
measurement interval and filter coefficient. obtained by a filter that is reasonably representative of an
average. For example, a rolling average is one such filter.
Implementations are expected to provide separately configurable Low or high delay MAY be the lowest and/or highest measured value
advertisement thresholds. All thresholds MUST be configurable on a over a measurement interval or MAY make use of a filter, or other
per sub-TLV basis. technique to obtain a reasonable representation of a low and high
value representative of the interval with compensation for outliers.
The announcement of all sub-TLVs that do not include the A bit SHOULD The measurement interval, any filter coefficients, and any
be controlled by variation thresholds that govern when they are sent. advertisement intervals MUST be configurable per sub-TLV.
Sub-TLV that include the A bit are governed by several thresholds. In addition to the measurement intervals governing re-advertisement,
Firstly, a threshold SHOULD be implemented to govern the announcement implementations SHOULD provide per sub-TLV configurable accelerated
of sub-TLVs that advertise a change in performance, but not an SLA advertisement thresholds, such that:
violation (i.e. when the A bit is not set). Secondly, implementations
MUST provide configurable thresholds that govern the announcement of 1. If the measured parameter falls outside a configured upper bound
sub-TLVs with the A bit set (for the indication of a performance for all but the min delay metric (or lower bound for min-delay
violation). Thirdly, implementations SHOULD provide reuse metric only) and the advertised sub-TLV is not already outside
thresholds. This threshold governs sub-TLV re-announcement with the A that bound or,
bit cleared to permit fail back.
2. If the difference between the last advertised value and current
measured value exceed a configured threshold then,
3. The advertisement is made immediately.
4. For sub-TLVs which include an A-bit (except low/high delay), an
additional threshold SHOULD be included corresponding to the
threshold for which the performance is considered anomalous (and
sub-TLVs with the A bit are sent). The A-bit is cleared when the
sub-TLV's performance has been below (or re-crosses) this
threshold for an advertisement interval(s) to permit fail back.
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
both.
Additionally, once outside of the bounds of the threshold, any
readvertisement of a measurement within the bounds would remain
governed solely by the measurement interval for that sub-TLV.
6. Announcement Suppression 6. Announcement Suppression
When link performance average values change, but fall under the When link performance values change by small amounts that fall under
threshold that would cause the announcement of a sub-TLV with the A thresholds that would cause the announcement of a sub-TLV,
bit set, implementations MAY suppress or throttle sub-TLV implementations SHOULD suppress sub-TLV readvertisement and/or
announcements. All suppression features and thresholds SHOULD be lengthen the period within which they are refreshed.
configurable.
Only the accelerated advertisement threshold mechanism described in
section 6 may shorten the re-advertisement interval.
All suppression and re-advertisement interval backoff timer features
SHOULD be configurable.
7. Network Stability and Announcement Periodicity 7. Network Stability and Announcement Periodicity
To mitigate concerns about stability, all values (except residual Sections 6 and 7 provide configurable mechanisms to bound the number
bandwidth) MUST be calculated as rolling averages where the averaging of re-advertisements. Instability might occur in very large networks
period MUST be a configurable period of time, rather than if measurement intervals are set low enough to overwhelm the
instantaneous measurements. processing of flooded information at some of the routers in the
topology. Therefore care SHOULD be taken in setting these values.
Additionally, the default measurement interval for all sub-TLVs
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 is inter-update throttle timers. The minimum announcement periodicity is
1 announcement per second. 1 announcement per second. The default value SHOULD be set to 120
seconds.
8. Compatibility Implementations SHOULD NOT permit the inter-update timer to be lower
than the measurement interval.
Furthermore, it is RECOMMENDED that any underlying performance
measurement mechanisms not include any significant buffer delay, any
significant buffer induced delay variation, or any significant
loss due to buffer overflow or due to active queue management.
8. Enabling and Disabling Sub-TLVs
Implementations MUST make it possible to individually enable or
disable each sub-TLV based on configuration.
9. Static Metric Override
Implementations SHOULD permit the static configuration and/or manual
override of dynamic measurements data on a per sub-TLV, per metric
basis in order to simplify migrations and to mitigate scenarios where
measurements are not possible across an entire network.
10. Compatibility
As per (RFC3630), unrecognized TLVs should be silently ignored As per (RFC3630), unrecognized TLVs should be silently ignored
9. Security Considerations 11. Security Considerations
This document does not introduce security issues beyond those This document does not introduce security issues beyond those
discussed in [RFC3630] and [RFC5329]. discussed in [RFC3630] and [RFC5329].
10. IANA Considerations 12. IANA Considerations
IANA maintains the registry for the sub-TLVs. OSPF TE Metric IANA maintains the registry for the sub-TLVs. OSPF TE Metric
Extensions will require one new type code per sub-TLV defined in this Extensions will require one new type code per sub-TLV defined in this
document. document.
11. References 13. References
11.1. 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, March 1997. Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC3630] Katz, D., Kompella, K., Yeung, D., "Traffic [RFC3630] Katz, D., Kompella, K., Yeung, D., "Traffic
Engineering (TE) Extensions to OSPF Version 2", RFC 3630, Engineering (TE) Extensions to OSPF Version 2", RFC 3630,
September 2003. September 2003.
[RFC6374] Frost, D. and S. Bryant, "Packet Loss and Delay [RFC6374] Frost, D. and S. Bryant, "Packet Loss and Delay
Measurement for MPLS Networks", RFC 6374, September 2011. Measurement for MPLS Networks", RFC 6374, September 2011.
11.2. Informative References 13.2. Informative References
[RFC2328] Moy, J, "OSPF Version 2", RFC 2328, April 1998 [RFC2328] Moy, J, "OSPF Version 2", RFC 2328, April 1998
[RFC3031] Rosen, E., Viswanathan, A., Callon, R., "Multiprotocol [RFC3031] Rosen, E., Viswanathan, A., Callon, R., "Multiprotocol
Label Switching Architecture", January 2001 Label Switching Architecture", January 2001
[RFC3209] Awduche, D., Berger, L., Gan, D., Li, T., Srinivasan, [RFC3209] Awduche, D., Berger, L., Gan, D., Li, T., Srinivasan,
V., and G. Swallow, "RSVP-TE: Extensions to RSVP for LSP V., and G. Swallow, "RSVP-TE: Extensions to RSVP for LSP
Tunnels", RFC 3209, December 2001. Tunnels", RFC 3209, December 2001.
[RFC5250] Berger, L., Bryskin I., Zinin, A., Coltun, R., "The OSPF [RFC5250] Berger, L., Bryskin I., Zinin, A., Coltun, R., "The OSPF
Opaque LSA Option", RFC 5250, July 2008. Opaque LSA Option", RFC 5250, July 2008.
[RFC6375] Frost, D. and S. Bryant, "A Packet Loss and Delay [RFC6375] Frost, D. and S. Bryant, "A Packet Loss and Delay
Measurement Profile for MPLS-Based Transport Networks", Measurement Profile for MPLS-Based Transport Networks",
RFC 6375, September 2011. RFC 6375, September 2011.
[Alto] R. Alimi R. Penno Y. Yang, "ALTO Protocol" [Alto] R. Alimi R. Penno Y. Yang, "ALTO Protocol"
12. Acknowledgments 14. Acknowledgments
The authors would like to recognize Ayman Soliman for his The authors would like to recognize Ayman Soliman, Nabil Bitar, David
contributions. McDysan, Edward Crabbe, and Don Fedyk for their contributions.
The authors also recognize Curtis Villamizar for significant comments
and direct content collaboration.
This document was prepared using 2-Word-v2.0.template.dot. This document was prepared using 2-Word-v2.0.template.dot.
13. Author's Addresses 15. Author's Addresses
Spencer Giacalone Spencer Giacalone
Thomson Reuters Thomson Reuters
195 Broadway 195 Broadway
New York, NY 10007, USA New York, NY 10007, USA
Email: Spencer.giacalone@thomsonreuters.com Email: Spencer.giacalone@thomsonreuters.com
Dave Ward Dave Ward
Cisco Systems Cisco Systems
 End of changes. 62 change blocks. 
126 lines changed or deleted 273 lines changed or added

This html diff was produced by rfcdiff 1.41. The latest version is available from http://tools.ietf.org/tools/rfcdiff/