draft-ietf-ospf-te-metric-extensions-04.txt   draft-ietf-ospf-te-metric-extensions-05.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: December 2013 D. Ward Expires: June 2014 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
June 3, 2013 December 5, 2013
OSPF Traffic Engineering (TE) Metric Extensions OSPF Traffic Engineering (TE) Metric Extensions
draft-ietf-ospf-te-metric-extensions-04.txt draft-ietf-ospf-te-metric-extensions-05.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
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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 December 3, 2013. This Internet-Draft will expire on May 5, 2014.
Copyright Notice Copyright Notice
Copyright (c) 2013 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
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1. Introduction...................................................4 1. Introduction...................................................4
2. Conventions used in this document..............................5 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................................................7 4. Sub TLV Details................................................7
4.1. Unidirectional Link Delay Sub-TLV.........................7 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..........................................8
4.2. Min/Max Unidirectional Link Delay Sub-TLV.................8 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. A bit................................................8 4.2.3. A bit................................................8
4.2.4. Reserved.............................................8 4.2.4. Reserved.............................................9
4.2.5. Low Delay............................................9 4.2.5. Low Delay............................................9
4.2.6. High Delay...........................................9 4.2.6. High Delay...........................................9
4.2.7. Reserved.............................................9 4.2.7. Reserved.............................................9
4.3. Unidirectional Delay Variation Sub-TLV....................9 4.3. Unidirectional Delay Variation Sub-TLV...................10
4.3.1. Type................................................10 4.3.1. Type................................................10
4.3.2. Length..............................................10 4.3.2. Length..............................................10
4.3.3. Reserved............................................10 4.3.3. Reserved............................................10
4.3.4. Delay Variation.....................................10 4.3.4. Delay Variation.....................................10
4.4. Unidirectional Link Loss Sub-TLV.........................10 4.4. Unidirectional Link Loss Sub-TLV.........................10
4.4.1. Type................................................11 4.4.1. Type................................................11
4.4.2. Length..............................................11 4.4.2. Length..............................................11
4.4.3. A bit...............................................11 4.4.3. A bit...............................................11
4.4.4. Reserved............................................11 4.4.4. Reserved............................................11
4.4.5. Link Loss...........................................11 4.4.5. Link Loss...........................................11
4.5. Unidirectional Residual Bandwidth Sub-TLV................11 4.5. Unidirectional Residual Bandwidth Sub-TLV................12
4.5.1. Type................................................12 4.5.1. Type................................................12
4.5.2. Length..............................................12 4.5.2. Length..............................................12
4.5.3. Residual Bandwidth..................................12 4.5.3. Residual Bandwidth..................................12
4.5. Unidirectional Available Bandwidth Sub-TLV...............13 4.6. Unidirectional Available Bandwidth Sub-TLV...............13
4.5.4. Type................................................13 4.6.1. Type................................................13
4.5.5. Length..............................................13 4.6.2. Length..............................................13
4.5.6. Available Bandwidth.................................13 4.6.3. Available Bandwidth.................................13
5. Announcement Thresholds and Filters...........................13 4.7. Unidirectional Utilized Bandwidth Sub-TLV................13
6. Announcement Suppression......................................14 4.7.1. Type................................................14
7. Network Stability and Announcement Periodicity................15 4.7.2. Length..............................................14
8. Enabling and Disabling Sub-TLVs...............................15 4.7.3. Utilized Bandwidth..................................14
9. Static Metric Override........................................15 5. Announcement Thresholds and Filters...........................14
10. Compatibility................................................16 6. Announcement Suppression......................................15
11. Security Considerations......................................16 7. Network Stability and Announcement Periodicity................16
12. IANA Considerations..........................................16 8. Enabling and Disabling Sub-TLVs...............................16
13. References...................................................16 9. Static Metric Override........................................16
13.1. Normative References....................................16 10. Compatibility................................................17
13.2. Informative References..................................16 11. Security Considerations......................................17
14. Acknowledgments..............................................17 12. IANA Considerations..........................................17
15. Author's Addresses...........................................17 13. References...................................................17
13.1. Normative References....................................17
13.2. Informative References..................................17
14. Acknowledgments..............................................18
15. Author's 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
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TE Metric Extensions"), that can be used to distribute network TE Metric Extensions"), that can be used to distribute network
performance information (such as link delay, delay variation, packet performance information (such as link delay, delay variation, packet
loss, residual bandwidth, and available bandwidth). loss, residual bandwidth, and available bandwidth).
The data distributed by OSPF TE Metric Extensions is meant to be used The data distributed by OSPF TE Metric Extensions is meant to be used
as part of the operation of the routing protocol (e.g. by replacing as part of the operation of the routing protocol (e.g. by replacing
cost with latency or considering bandwidth as well as cost), by cost with latency or considering bandwidth as well as cost), by
enhancing CSPF, or for other uses such as supplementing the data used enhancing CSPF, or for other uses such as supplementing the data used
by an Alto server [Alto]. With respect to CSPF, the data distributed by an Alto server [Alto]. With respect to CSPF, the data distributed
by OSPF TE Metric Extensions can be used to setup, fail over, and by OSPF TE Metric Extensions can be used to setup, fail over, and
fail back data paths using protocols such as RSVP-TE [RFC3209]. fail back data paths using protocols such as RSVP-TE [RFC3209].[
Draft-ietf-mpls-te-express-path] describes some methods for using
this information to compute Label Switched Paths (LSPs) at the LSP
ingress.
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 and/or loss SHOULD NOT offered traffic load. Thus, queuing delays and/or loss SHOULD NOT
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TBD2 8 Low/High Unidirectional Link Delay TBD2 8 Low/High Unidirectional Link Delay
TBD3 4 Unidirectional Delay Variation TBD3 4 Unidirectional Delay Variation
TBD4 4 Unidirectional Packet Loss TBD4 4 Unidirectional Packet Loss
TBD5 4 Unidirectional Residual Bandwidth TBD5 4 Unidirectional Residual Bandwidth
TBD6 4 Unidirectional Available Bandwidth TBD6 4 Unidirectional Available Bandwidth
TBD7 4 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.
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.
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value and may be larger. 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 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| TBD4 | 4 | | TBD4 | 4 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|A| RESERVED | Link Loss | |A| RESERVED | Link Loss |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
4.4.1. Type 4.4.1. Type
This sub-TLV has a type of TBD4 This sub-TLV has a type of TBD4
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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.
4.5. Unidirectional Residual Bandwidth Sub-TLV 4.5. Unidirectional Residual Bandwidth Sub-TLV
This TLV advertises the residual bandwidth (defined in section 4.5.3. This sub-TLV advertises the residual bandwidth between two directly
between two directly connected OSPF neighbors. The residual bandwidth connected OSPF neighbors. The residual bandwidth advertised by this
advertised by this sub-TLV MUST be the residual bandwidth from the sub-TLV MUST be the residual bandwidth from the system originating
system originating the LSA to its neighbor. 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| TBD5 | 4 | | TBD5 | 4 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Residual Bandwidth | | Residual Bandwidth |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
4.5.1. Type 4.5.1. Type
This sub-TLV has a type of TBD5. This sub-TLV has a type of TBD5.
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reservations from Maximum Bandwidth (i.e. the link capacity) reservations from Maximum Bandwidth (i.e. the link capacity)
[RFC3630] and provides an aggregated remainder across QoS classes. [RFC3630] and provides an aggregated remainder across QoS classes.
Unreserved Bandwidth [RFC3630], on the other hand, is subtracted from Unreserved Bandwidth [RFC3630], on the other hand, is subtracted from
the Maximum Reservable Bandwidth (the bandwidth that can the Maximum Reservable Bandwidth (the bandwidth that can
theoretically be reserved) [RFC3630] and provides per-QoS-class theoretically be reserved) [RFC3630] and provides per-QoS-class
remainders. Residual Bandwidth and Unreserved Bandwidth [RFC3630] can remainders. Residual Bandwidth and Unreserved Bandwidth [RFC3630] can
be used concurrently, and each has a separate use case (e.g. the be used concurrently, and each has a separate use case (e.g. the
former can be used for applications like Weighted ECMP while the former can be used for applications like Weighted ECMP while the
latter can be used for call admission control). latter can be used for call admission control).
4.5. Unidirectional Available Bandwidth Sub-TLV 4.6. Unidirectional Available Bandwidth Sub-TLV
This TLV advertises the available bandwidth (defined in section This TLV advertises the available bandwidth between two directly
4.5.6. ) between two directly connected OSPF neighbors. The available connected OSPF neighbors. The available bandwidth advertised by this
bandwidth advertised by this sub-TLV MUST be the available bandwidth sub-TLV MUST be the available bandwidth from the system originating
from the system originating the LSA to its neighbor. The format of the LSA to its neighbor. The format of this sub-TLV is shown in the
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| TBD6 | 4 | | TBD6 | 4 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Available Bandwidth | | Available Bandwidth |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
4.5.4. Type 4.6.1. Type
This sub-TLV has a type of TBD6. This sub-TLV has a type of TBD6.
4.5.5. Length 4.6.2. Length
The length is 4. The length is 4.
4.5.6. Available Bandwidth 4.6.3. 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 4.5. ) 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.
4.7. Unidirectional Utilized Bandwidth Sub-TLV
This Sub-TLV advertises the bandwidth utilization between two
directly connected OSPF neighbors. The bandwidth utilization
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
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| TBD7 | 4 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Utilized Bandwidth |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
4.7.1. Type
This sub-TLV has a type of TBD7.
4.7.2. Length
The length is 4.
4.7.3. Utilized Bandwidth
This field carries the bandwidth utilization on a link, forwarding
adjacency, or bundled link in IEEE floating point format with units
of bytes per second. For a link or forwarding adjacency, bandwidth
utilization represents the actual utilization of the link (i.e. as
measured in the router). For a bundled link, bandwidth utilization is
defined to be the sum of the component link bandwidth utilizations.
5. Announcement Thresholds and Filters 5. Announcement Thresholds and Filters
The values advertised in all sub-TLVs (except min/max delay and The values advertised in all sub-TLVs (except 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 obtained by a filter that is reasonably representative of an
average. For example, a rolling average is one such filter. average. For example, a rolling average is one such filter.
Low or high delay MAY be the lowest and/or highest measured value Low or high delay MAY be the lowest and/or highest measured value
over a measurement interval or MAY make use of a filter, or other over a measurement interval or MAY make use of a filter, or other
technique to obtain a reasonable representation of a low and high technique to obtain a reasonable representation of a low and high
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[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"
[Draft-ietf-mpls-te-express-path] Atlas, A., Drake, J., Giacalone,
S., Ward, D., Previdi, S., and C. Filsfils, "Performance-
based Path Selection for Explicitly Routed LSPs using TE
Metric Extensions", Draft-ietf-mpls-te-express-path (work
in progress), October 2013
14. Acknowledgments 14. Acknowledgments
The authors would like to recognize Ayman Soliman, Nabil Bitar, David The authors would like to recognize Ayman Soliman, Nabil Bitar, David
McDysan, Edward Crabbe, and Don Fedyk for their contributions. McDysan, Edward Crabbe, and Don Fedyk for their contributions.
The authors also recognize Curtis Villamizar for significant comments The authors also recognize Curtis Villamizar for significant comments
and direct content collaboration. 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.
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