draft-ietf-bmwg-igp-dataplane-conv-term-04.txt   draft-ietf-bmwg-igp-dataplane-conv-term-05.txt 
Network Working Group Network Working Group
INTERNET-DRAFT INTERNET-DRAFT
Expires in: April 2005 Expires in: October 2005
Scott Poretsky Scott Poretsky
Quarry Technologies Quarry Technologies
Brent Imhoff Brent Imhoff
LightCore LightCore
October 2004 February 2005
Terminology for Benchmarking Terminology for Benchmarking
IGP Data Plane Route Convergence IGP Data Plane Route Convergence
<draft-ietf-bmwg-igp-dataplane-conv-term-04.txt> <draft-ietf-bmwg-igp-dataplane-conv-term-05.txt>
Intellectual Property Rights (IPR) statement: Intellectual Property Rights (IPR) statement:
By submitting this Internet-Draft, I certify that any applicable By submitting this Internet-Draft, I certify that any applicable
patent or other IPR claims of which I am aware have been disclosed, or patent or other IPR claims of which I am aware have been disclosed, or
will be disclosed, and any of which I become aware will be disclosed, will be disclosed, and any of which I become aware will be disclosed,
in accordance with RFC 3668. in accordance with RFC 3668.
Status of this Memo Status of this Memo
This document is an Internet-Draft and is in full conformance with This document is an Internet-Draft and is in full conformance with
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3.5 Convergence Packet Loss...................................5 3.5 Convergence Packet Loss...................................5
3.6 Convergence Event Instant.................................6 3.6 Convergence Event Instant.................................6
3.7 Convergence Recovery Instant..............................6 3.7 Convergence Recovery Instant..............................6
3.8 Rate-Derived Convergence Time.............................7 3.8 Rate-Derived Convergence Time.............................7
3.9 Convergence Event Transition..............................7 3.9 Convergence Event Transition..............................7
3.10 Convergence Recovery Transition..........................8 3.10 Convergence Recovery Transition..........................8
3.11 Loss-Derived Convergence Time............................8 3.11 Loss-Derived Convergence Time............................8
3.12 Sustained Forwarding Convergence Time....................9 3.12 Sustained Forwarding Convergence Time....................9
3.13 Restoration Convergence Time.............................9 3.13 Restoration Convergence Time.............................9
3.14 Packet Sampling Interval.................................10 3.14 Packet Sampling Interval.................................10
3.15 Local Interface..........................................10 3.15 Local Interface..........................................11
3.16 Neighbor Interface.......................................11 3.16 Neighbor Interface.......................................11
3.17 Remote Interface........................................11 3.17 Remote Interface.........................................11
3.18 Preferred Egress Interface...............................11 3.18 Preferred Egress Interface...............................12
3.19 Next-Best Egress Interface..............................12 3.19 Next-Best Egress Interface...............................12
3.20 Stale Forwarding.........................................12 3.20 Stale Forwarding.........................................13
3.21 Nested Convergence Events................................13
4. Security Considerations.......................................13 4. Security Considerations.......................................13
5. References....................................................13 5. Normative References..........................................14
6. Author's Address..............................................13 6. Author's Address..............................................14
1. Introduction 1. Introduction
This draft describes the terminology for benchmarking IGP Route This draft describes the terminology for benchmarking IGP Route
Convergence. The motivation and applicability for this Convergence. The motivation and applicability for this
benchmarking is provided in [1]. The methodology to be used for benchmarking is provided in [1]. The methodology to be used for
this benchmarking is described in [2]. The methodology and this benchmarking is described in [2]. The methodology and
terminology to be used for benchmarking Route Convergence can be terminology to be used for benchmarking Route Convergence can be
applied to any link-state IGP such as ISIS [3] and OSPF [4]. The applied to any link-state IGP such as ISIS [3] and OSPF [4]. The
data plane is measured to obtain black-box (externally observable) data plane is measured to obtain black-box (externally observable)
convergence benchmarking metrics. The purpose of this document is convergence benchmarking metrics. The purpose of this document is
to introduce new terms required to complete execution of the IGP to introduce new terms required to complete execution of the IGP
Route Convergence Methodology [2]. Route Convergence Methodology [2]. These terms apply to IPv4 and
IPv6 traffic as well as IPv4 and IPv6 IGPs.
An example of Route Convergence as observed and measured from the An example of Route Convergence as observed and measured from the
data plane is shown in Figure 1. The graph in Figure 1 shows data plane is shown in Figure 1. The graph in Figure 1 shows
Forwarding Rate versus Time. Time 0 on the X-axis is on the far Forwarding Rate versus Time. Time 0 on the X-axis is on the far
right of the graph. The components of the graph and metrics are right of the graph. The components of the graph and metrics are
defined in the Term Definitions section. defined in the Term Definitions section.
IGP Data Plane Route Convergence IGP Data Plane Route Convergence
Convergence Convergence Convergence Convergence
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\ Loss /<----Convergence \ Loss /<----Convergence
Convergence------->\ / Event Transition Convergence------->\ / Event Transition
Recovery Transition \ / Recovery Transition \ /
\_____/<------Packet Loss \_____/<------Packet Loss
X-axis = Time X-axis = Time
Y-axis = Forwarding Rate Y-axis = Forwarding Rate
Figure 1. Convergence Graph Figure 1. Convergence Graph
2. Existing definitions 2. Existing definitions
For the sake of clarity and continuity this RFC adopts the template
for definitions set out in Section 2 of RFC 1242. Definitions are
indexed and grouped together in sections for ease of reference.
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 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
this document are to be interpreted as described in RFC 2119. document are to be interpreted as described in BCP 14, RFC 2119
[Br97]. RFC 2119 defines the use of these key words to help make the
intent of standards track documents as clear as possible. While this
document uses these keywords, this document is not a standards track
document.
3. Term Definitions 3. Term Definitions
3.1 Convergence Event 3.1 Convergence Event
Definition: Definition:
The occurrence of a planned or unplanned action in the network The occurrence of a planned or unplanned action in the network
that results in a change in the egress interface of the DUT for that results in a change in the egress interface of the DUT for
routed packets. routed packets.
Discussion: Discussion:
Convergence Events include link loss, routing protocol session Convergence Events include link loss, routing protocol session
loss, router failure, configuration change, and better next-hop loss, router failure, configuration change, and better next-hop
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Route Convergence Route Convergence
Stale Forwarding Stale Forwarding
IGP Data Plane Route Convergence IGP Data Plane Route Convergence
3.4 Full Convergence 3.4 Full Convergence
Definition: Definition:
Route Convergence for an entire FIB. Route Convergence for an entire FIB.
Discussion: Discussion:
When benchmarking convergence it is useful to measure When benchmarking convergence it is useful to measure
the time to converge an entire route table. For example, the time to converge an entire FIB. For example,
a Convergence Event can be produced for an OSPF table of
a Convergence Event can be produced for an OSPF table of 5000 5000 routes so that the time to converge routes 1 through
routes so that the time to converge routes 1 through 5000 5000 is measured. Full Convergence is externally observable
is measured. from the data plane when the forwarding rate on the Next-Best
Egress Interface equals the offered load.
Measurement Units: Measurement Units:
N/A N/A
Issues: Issues:
None None
See Also: See Also:
Network Convergence Network Convergence
Route Convergence Route Convergence
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See Also: See Also:
Convergence Event Convergence Event
Convergence Packet Loss Convergence Packet Loss
Convergence Recovery Instant Convergence Recovery Instant
3.7 Convergence Recovery Instant 3.7 Convergence Recovery Instant
Definition: Definition:
The time instant that Full Convergence is measured The time instant that Full Convergence is measured
and maintained for at least an additional five seconds. and then maintained for an interval of duration equal to
the Sustained Forwarding Convergence Time
Discussion: Discussion:
Convergence Recovery Instant is measurable from the data Convergence Recovery Instant is measurable from the data
plane as the precise time that the device under test plane as the precise time that the device under test
achieves Full Convergence. Convergence Recovery Instant achieves Full Convergence.
is externally observable from the data plane when the
forwarding rate on the Next-Best Egress Interface equals
the offered rate.
Measurement Units: Measurement Units:
hh:mm:ss:uuu hh:mm:ss:uuu
Issues: Issues:
None None
See Also: See Also:
Sustained Forwarding Convergence Time
Convergence Packet Loss Convergence Packet Loss
Convergence Event Instant Convergence Event Instant
IGP Data Plane Route Convergence IGP Data Plane Route Convergence
3.8 Rate-Derived Convergence Time 3.8 Rate-Derived Convergence Time
Definition: Definition:
The amount of time for Convergence Packet Loss to The amount of time for Convergence Packet Loss to persist upon
persist upon occurrence of a Convergence Event until occurrence of a Convergence Event until occurrence of Route
occurrence of Route Convergence. Convergence.
Discussion:
Rate-Derived Convergence Time can be measured as the time Rate-Derived Convergence Time can be measured as the time
difference from the Convergence Event Instant to the difference from the Convergence Event Instant to the
Convergence Recovery Instant, as shown with Equation 1. Convergence Recovery Instant, as shown with Equation 1.
(eq 1) Rate-Derived Convergence Time = (eq 1) Rate-Derived Convergence Time =
Convergence Recovery Instant - Convergence Event Instant. Convergence Recovery Instant - Convergence Event Instant.
Discussion:
Rate-Derived Convergence Time should be measured at the maximum Rate-Derived Convergence Time should be measured at the maximum
forwarding rate. Failure to achieve Full Convergence results in forwarding rate. Failure to achieve Full Convergence results in
a Rate-Derived Convergence Time benchmark of infinity. a Rate-Derived Convergence Time benchmark of infinity.
Measurement Units: Measurement Units:
seconds/milliseconds seconds/milliseconds
Issues: Issues:
None None
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Full Convergence Full Convergence
Rate-Derived Convergence Time Rate-Derived Convergence Time
Convergence Packet Loss Convergence Packet Loss
Convergence Event Transition Convergence Event Transition
3.11 Loss-Derived Convergence Time 3.11 Loss-Derived Convergence Time
Definition: Definition:
The amount of time it takes for Route Convergence to The amount of time it takes for Route Convergence to
to be achieved as calculated from the Convergence Packet to be achieved as calculated from the Convergence Packet
Loss. Loss. Loss-Derived Convergence Time can be calculated
from Convergence Packet Loss that occurs due to a
Discussion: Convergence Event and Route Convergence.as shown with
Loss-Derived Convergence Time can be calculated from Equation 2.
Convergence Packet Loss that occurs due to a Convergence Event
and Route Convergence, as shown with Equation 2.
(eq 2) Loss-Derived Convergence Time = (eq 2) Loss-Derived Convergence Time =
Convergence Packets Loss / Forwarding Rate Convergence Packets Loss / Offered Load
NOTE: Units for this measurement are NOTE: Units for this measurement are
packets / packets/second = seconds packets / packets/second = seconds
Measurement Units: Discussion:
seconds/milliseconds
Issues:
Loss-Derived Convergence Time gives a better than Loss-Derived Convergence Time gives a better than
actual result when converging many routes simultaneously. actual result when converging many routes simultaneously.
Rate-Derived Convergence Time takes the Convergence Recovery Rate-Derived Convergence Time takes the Convergence Recovery
Transition into account, but Loss-Derived Convergence Time Transition into account, but Loss-Derived Convergence Time
ignores the Route Convergence Recovery Transition because ignores the Route Convergence Recovery Transition because
it is obtained from the measured Convergence Packet Loss. it is obtained from the measured Convergence Packet Loss.
Ideally, the Convergence Event Transition and Convergence Ideally, the Convergence Event Transition and Convergence
IGP Data Plane Route Convergence
Recovery Transition are instantaneous so that the Recovery Transition are instantaneous so that the
Rate-Derived Convergence Time = Loss-Derived Convergence Time. Rate-Derived Convergence Time = Loss-Derived Convergence Time.
However, router implementations are less than ideal. However, router implementations are less than ideal.
For these reasons the preferred reporting benchmark for IGP For these reasons the preferred reporting benchmark for IGP
Route Convergence is the Rate-Derived Convergence Time. Route Convergence is the Rate-Derived Convergence Time.
IGP Data Plane Route Convergence
Guidelines for reporting Loss-Derived Convergence Time are Guidelines for reporting Loss-Derived Convergence Time are
provided in [2]. provided in [2].
Measurement Units:
seconds/milliseconds
Issues:
None
See Also: See Also:
Route Convergence Route Convergence
Convergence Packet Loss Convergence Packet Loss
Rate-Derived Convergence Time Rate-Derived Convergence Time
Convergence Event Transition Convergence Event Transition
Convergence Recovery Transition Convergence Recovery Transition
3.12 Sustained Forwarding Convergence Time 3.12 Sustained Forwarding Convergence Time
Definition: Definition:
The amount of time for Route Convergence to be achieved for The amount of time for which Full Convergence is maintained without
cases in which there is no packet loss. additional packet loss.
Discussion: Discussion:
Sustained Forwarding Convergence Time is the IGP Route Convergence The purpose of the Sustained Forwarding Convergence Time is to produce
benchmark to be used for Convergence Events that produce Convergence Time benchmarks protected against fluctuation in Forwarding
a change in next-hop without packet loss. Rate after Full Convergence is observed. The Sustained Forwarding
Convergence Time to be used is calculated as shown in Equation 3.
(eq 3)
Sustained Forwarding Convergence Time =
5 x (# routes in FIB) / (Offered Load)
for which at least one packet per destination MUST be received at
the DUT.
Measurement Units: Measurement Units:
seconds/milliseconds seconds or milliseconds
Issues: Issues: None
None
See Also: See Also:
Route Convergence Full Convergence
Rate-Derived Convergence Time Convergence Recovery Instant
Loss-Derived Convergence Time
3.13 Restoration Convergence Time 3.13 Restoration Convergence Time
Definition: Definition:
The amount of time for the router under test to restore The amount of time for the router under test to restore
traffic to the original outbound port after recovery from traffic to the original outbound port after recovery from
a Convergence Event. a Convergence Event.
IGP Data Plane Route Convergence
Discussion: Discussion:
Restoration Convergence Time is the amount of time to Restoration Convergence Time is the amount of time to
Converge back to the original outbound port. This is achieved Converge back to the original outbound port. This is achieved
by recovering from the Convergence Event, such as restoring by recovering from the Convergence Event, such as restoring
the failed link. Restoration Convergence Time is measured the failed link. Restoration Convergence Time is measured
using the Rate-Derived Convergence Time calculation technique, using the Rate-Derived Convergence Time calculation technique,
as provided in Equation 1. It is possible, but not desired as provided in Equation 1. It is possible, but not desired
IGP Data Plane Route Convergence
to have the Restoration Convergence Time differ from the to have the Restoration Convergence Time differ from the
Rate-Derived Convergence Time. Rate-Derived Convergence Time.
Measurement Units: Measurement Units:
seconds or milliseconds seconds or milliseconds
Issues: Issues:
None None
See Also: See Also:
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Transition and Convergence Recovery Transition can become Transition and Convergence Recovery Transition can become
exaggerated when the Packet Sampling Interval is too long. exaggerated when the Packet Sampling Interval is too long.
This will produce a larger than actual Rate-Derived This will produce a larger than actual Rate-Derived
Convergence Time. The recommended value for configuration Convergence Time. The recommended value for configuration
of the Packet Sampling Interval is provided in [2]. of the Packet Sampling Interval is provided in [2].
See Also: See Also:
Convergence Packet Loss Convergence Packet Loss
Convergence Event Transition Convergence Event Transition
Convergence Recovery Transition Convergence Recovery Transition
IGP Data Plane Route Convergence
3.15 Local Interface 3.15 Local Interface
Definition: Definition:
An interface on the DUT. An interface on the DUT.
Discussion: Discussion:
None None
Measurement Units: Measurement Units:
N/A N/A
IGP Data Plane Route Convergence
Issues: Issues:
None None
See Also: See Also:
Neighbor Interface Neighbor Interface
Remote Interface Remote Interface
3.16 Neighbor Interface 3.16 Neighbor Interface
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connected to any interface on the DUT. connected to any interface on the DUT.
Discussion: Discussion:
None None
Measurement Units: Measurement Units:
N/A N/A
Issues: Issues:
None None
IGP Data Plane Route Convergence
See Also: See Also:
Local Interface Local Interface
Neighbor Interface Neighbor Interface
3.18 Preferred Egress Interface 3.18 Preferred Egress Interface
Definition: Definition:
The outbound interface from the DUT for traffic routed to the The outbound interface from the DUT for traffic routed to the
preferred next-hop. preferred next-hop.
IGP Data Plane Route Convergence
Discussion: Discussion:
Preferred Egress Interface is the egress interface prior to Preferred Egress Interface is the egress interface prior to
a Convergence Event a Convergence Event
Measurement Units: Measurement Units:
N/A N/A
Issues: Issues:
None None
See Also: See Also:
Next-Best Egress Interface Next-Best Egress Interface
3.19 Next-Best Egress Interface 3.19 Next-Best Egress Interface
Definition: Definition:
The outbound interface from the DUT for traffic routed to the The outbound interface from the DUT for traffic routed to the
second-best next-hop. second-best next-hop. It is the same media type and link speed
as the Preferred Egress Interface
Discussion: Discussion:
Next-Best Egress Interface is the egress interface after Next-Best Egress Interface is the egress interface after
a Convergence Event. a Convergence Event.
Measurement Units: Measurement Units:
N/A N/A
Issues: Issues:
None None
See Also: See Also:
Preferred Egress Interface Preferred Egress Interface
IGP Data Plane Route Convergence
3.20 Stale Forwarding 3.20 Stale Forwarding
Definition: Definition:
Forwarding of traffic to route entries that no longer exist Forwarding of traffic to route entries that no longer exist
or to route entries with next-hops that are no longer preferred. or to route entries with next-hops that are no longer preferred.
Discussion: Discussion:
Stale Forwarding can be caused by a Convergence Event and is Stale Forwarding can be caused by a Convergence Event and is
also known as a "black-hole" since it may produce packet loss. also known as a "black-hole" since it may produce packet loss.
Stale Forwarding exists until Network Convergence is achieved. Stale Forwarding exists until Network Convergence is achieved.
Measurement Units: Measurement Units:
N/A N/A
Issues: Issues:
None None
See Also: See Also:
Network Convergence Network Convergence
IGP Data Plane Route Convergence
3.21 Nested Convergence Events
Definition:
The occurence of Convergence Event while the route table
is converging from a prior Convergence Event.
Discussion:
The Convergence Events for a Nested Convergence Events
MUST occur with different neighbors. A common
observation from a Nested Convergence Event will be
the withdrawal of routes from one neighbor while the
routes of another neighbor are being installed.
Measurement Units:
N/A
Issues:
None
See Also:
Convergence Event
4. Security Considerations 4. Security Considerations
Documents of this type do not directly affect the security of Documents of this type do not directly affect the security of
Internet or corporate networks as long as benchmarking Internet or corporate networks as long as benchmarking
is not performed on devices or systems connected to operating is not performed on devices or systems connected to operating
networks. networks.
5. References IGP Data Plane Route Convergence
5. Normative References
[1] Poretsky, S., "Benchmarking Applicability for IGP Data Plane [1] Poretsky, S., "Benchmarking Applicability for IGP Data Plane
Route Convergence", draft-ietf-bmwg-igp-dataplane-conv-app-04, Route Convergence", draft-ietf-bmwg-igp-dataplane-conv-app-05,
work in progress, October 2004. work in progress, February 2005.
[2] Poretsky, S., "Benchmarking Methodology for IGP Data Plane [2] Poretsky, S., "Benchmarking Methodology for IGP Data Plane
Route Convergence", draft-ietf-bmwg-igp-dataplane-conv-meth-04, Route Convergence", draft-ietf-bmwg-igp-dataplane-conv-meth-05,
work in progress, October 2004. work in progress, February 2005.
[3] Callon, R., "Use of OSI IS-IS for Routing in TCP/IP and Dual [3] Callon, R., "Use of OSI IS-IS for Routing in TCP/IP and Dual
Environments", RFC 1195, December 1990. Environments", RFC 1195, December 1990.
[4] Moy, J., "OSPF Version 2", RFC 2328, IETF, April 1998. [4] Moy, J., "OSPF Version 2", RFC 2328, IETF, April 1998.
[5] S. Casner, C. Alaettinoglu, and C. Kuan, "A Fine-Grained View [5] S. Casner, C. Alaettinoglu, and C. Kuan, "A Fine-Grained View
of High Performance Networking", NANOG 22, May 2001. of High Performance Networking", NANOG 22, May 2001.
[6] L. Ciavattone, A. Morton, and G. Ramachandran, "Standardized [6] L. Ciavattone, A. Morton, and G. Ramachandran, "Standardized
skipping to change at page 14, line 4 skipping to change at page 14, line 42
Quarry Technologies Quarry Technologies
8 New England Executive Park 8 New England Executive Park
Burlington, MA 01803 Burlington, MA 01803
USA USA
Phone: + 1 781 395 5090 Phone: + 1 781 395 5090
EMail: sporetsky@quarrytech.com EMail: sporetsky@quarrytech.com
Brent Imhoff Brent Imhoff
USA USA
EMail: bimhoff@planetspork.com EMail: bimhoff@planetspork.com
IGP Data Plane Route Convergence
Intellectual Property Statement Intellectual Property Statement
The IETF takes no position regarding the validity or scope of any Intel- The IETF takes no position regarding the validity or scope of any Intel-
lectual Property Rights or other rights that might be claimed to pertain lectual Property Rights or other rights that might be claimed to pertain
to the implementation or use of the technology described in this docu- to the implementation or use of the technology described in this docu-
ment or the extent to which any license under such rights might or might ment or the extent to which any license under such rights might or might
not be available; nor does it represent that it has made any independent not be available; nor does it represent that it has made any independent
effort to identify any such rights. Information on the procedures with effort to identify any such rights. Information on the procedures with
respect to rights in RFC documents can be found in BCP 78 and BCP 79. respect to rights in RFC documents can be found in BCP 78 and BCP 79.
IGP Data Plane Route Convergence
Copies of IPR disclosures made to the IETF Secretariat and any Copies of IPR disclosures made to the IETF Secretariat and any
assurances of licenses to be made available, or the result of an attempt assurances of licenses to be made available, or the result of an attempt
made to obtain a general license or permission for the use of such made to obtain a general license or permission for the use of such
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obtained from the IETF on-line IPR repository at obtained from the IETF on-line IPR repository at
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The IETF invites any interested party to bring to its attention any The IETF invites any interested party to bring to its attention any
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that may cover technology that may be required to implement this stan- that may cover technology that may be required to implement this stan-
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This document and the information contained herein are provided on an This document and the information contained herein are provided on an
"AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS OR "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS OR
IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY AND THE INTERNET IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY AND THE INTERNET
ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED, ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED,
INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMA- INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMA-
TION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF TION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF
MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
Copyright Statement Copyright Statement
Copyright (C) The Internet Society (2004). This document is subject to Copyright (C) The Internet Society (2005). This document is subject to
the rights, licenses and restrictions contained in BCP 78, and except as the rights, licenses and restrictions contained in BCP 78, and except as
set forth therein, the authors retain all their rights. set forth therein, the authors retain all their rights.
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