Network Working Group Y. Lee
Internet Draft Huawei
Intended status: Standard Track
Expires: January 2012 G. Bernstein
Grotto Networking
Jonas Martensson
Acreo
T. Takeda
NTT
T. Tsuritani
KDDI
July 7, 2011
PCEP Extensions for WSON Impairments
draft-lee-pce-wson-impairments-02.txt
Status of this Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF), its areas, and its working groups. Note that
other groups may also distribute working documents as Internet-
Drafts.
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
The list of current Internet-Drafts can be accessed at
http://www.ietf.org/ietf/1id-abstracts.txt
The list of Internet-Draft Shadow Directories can be accessed at
http://www.ietf.org/shadow.html
This Internet-Draft will expire on January 7, 2009.
Lee & Bernstein Expires January 7, 2012 [Page 1]
Internet-Draft PCEP Extension for WSON Impairments July 2011
Copyright Notice
Copyright (c) 2011 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with respect
to this document. Code Components extracted from this document must
include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
Abstract
As an optical signal progresses along its path it may be altered by
the various physical processes in the optical fibers and devices it
encounters. When such alterations result in signal degradation, these
processes are usually referred to as "impairments". These physical
characteristics may be important constraints to consider in path
computation process in wavelength switched optical networks.
This document provides PCEP extensions to support Impairment Aware
Routing and Wavelength Assignment (IA-RWA) in wavelength switched
optical networks.
Conventions used in this document
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC-2119 0.
Table of Contents
1. Introduction...................................................3
1.1. WSON RWA Processes (no impairments).......................5
1.2. WSON IA-RWA Processes.....................................6
2. WSON PCE Architectures and Requirements........................7
Lee & Bernstein Expires January 7, 2012 [Page 2]
Internet-Draft PCEP Extension for WSON Impairments July 2011
2.1. RWA PCC to PCE Interface..................................8
2.1.1. A new RWA path request...............................8
2.1.1.1. Signal Quality Measure TLV......................9
2.1.2. A new RWA path reply................................10
2.1.2.1. Signal Quality Measure TLV.....................10
2.2. RWA-PCE to IV-PCE Interface..............................12
2.2.1. A new impairment-validated (IV) path request........13
2.2.2. A new impairment-validated (IV) path reply..........13
3. Manageability Considerations..................................13
3.1. Control of Function and Policy...........................13
3.2. Information and Data Models, e.g. MIB module.............14
3.3. Liveness Detection and Monitoring........................14
3.4. Verifying Correct Operation..............................14
3.5. Requirements on Other Protocols and Functional Components14
3.6. Impact on Network Operation..............................15
4. Security Considerations.......................................15
5. IANA Considerations...........................................15
6. References....................................................15
6.1. Normative References.....................................15
6.2. Informative References...................................16
Authors' Addresses...............................................16
7. Acknowledgments...............................................17
1. Introduction
[RFC4655] defines the PCE based Architecture and explains how a Path
Computation Element (PCE) may compute Label Switched Paths (LSP) in
Multiprotocol Label Switching Traffic Engineering (MPLS-TE) and
Generalized MPLS (GMPLS) networks at the request of Path Computation
Clients (PCCs). A PCC is shown to be any network component that
makes such a request and may be for instance an Optical Switching
Element within a Wavelength Division Multiplexing (WDM) network. The
PCE, itself, can be located anywhere within the network, and may be
within an optical switching element, a Network Management System
(NMS) or Operational Support System (OSS), or may be an independent
network server.
The PCE communication Protocol (PCEP) is the communication protocol
used between PCC and PCE, and may also be used between cooperating
PCEs. [RFC4657] sets out the common protocol requirements for PCEP.
Additional application-specific requirements for PCEP are deferred to
separate documents.
This document provides a set of application-specific PCEP
requirements for support of path computation in Wavelength Switched
Lee & Bernstein Expires January 7, 2012 [Page 3]
Internet-Draft PCEP Extension for WSON Impairments July 2011
Optical Networks (WSON) with impairments. WSON refers to WDM based
optical networks in which switching is performed selectively based on
the wavelength of an optical signal.
The path in WSON is referred to as a lightpath. A lightpath may span
multiple fiber links and the path should be assigned a wavelength for
each link. A transparent optical network is made up of optical
devices that can switch but not convert from one wavelength to
another. In a transparent optical network, a lightpath operates on
the same wavelength across all fiber links that it traverses. In such
case, the lightpath is said to satisfy the wavelength-continuity
constraint. Two lightpaths that share a common fiber link can not be
assigned the same wavelength. To do otherwise would result in both
signals interfering with each other. Note that advanced additional
multiplexing techniques such as polarization based multiplexing are
not addressed in this document since the physical layer aspects are
not currently standardized. Therefore, assigning the proper
wavelength on a lightpath is an essential requirement in the optical
path computation process.
When a switching node has the ability to perform wavelength
conversion the wavelength-continuity constraint can be relaxed, and a
lightpath may use different wavelengths on different links along its
route from origin to destination. It is, however, to be noted that
wavelength converters may be limited due to their relatively high
cost, while the number of WDM channels that can be supported in a
fiber is also limited. As a WSON can be composed of network nodes
that cannot perform wavelength conversion, nodes with limited
wavelength conversion, and nodes with full wavelength conversion
abilities, wavelength assignment is an additional routing constraint
to be considered in all lightpath computation.
One of the most basic questions in communications is whether one can
successfully transmit information from a transmitter to a receiver
within a prescribed error tolerance, usually specified as a maximum
permissible bit error ratio (BER). This generally depends on the
nature of the signal transmitted between the sender and receiver and
the nature of the communications channel between the sender and
receiver. The optical path utilized (along with the wavelength)
determines the communications channel.
The optical impairments incurred by the signal along the fiber and at
each optical network element along the path determine whether the BER
performance or any other measure of signal quality can be met for
this particular signal on this particular path. Given the existing
standards covering optical characteristics (impairments) and the
knowledge of how the impact of impairments may be estimated along a
Lee & Bernstein Expires January 7, 2012 [Page 4]
Internet-Draft PCEP Extension for WSON Impairments July 2011
path, [WSON-IMP] provides a framework for impairment aware path
computation and establishment utilizing GMPLS protocols and the PCE
architecture.
Some transparent optical subnetworks are designed such that over any
path the degradation to an optical signal due to impairments never
exceeds prescribed bounds. This may be due to the limited geographic
extent of the network, the network topology, and/or the quality of
the fiber and devices employed. In such networks the path selection
problem reduces to determining a continuous wavelength from source
to destination (the Routing and Wavelength Assignment problem).
These networks are discussed in [RFC6163]. In other optical
networks, impairments are important and the path selection process
must be impairment-aware.
In this document we first review the processes for routing and
wavelength assignment (RWA) used when wavelength continuity
constraints are present. We then review the processes for optical
impairment aware RWA (IA-RWA). Based on selected process models we
then specify requirements for PCEP to support IA-RWA. Note that
requirements for PCEP to support RWA are specified in a separate
document [PCEP-RWA].
The remainder of this document uses terminology from [RFC4655].
1.1. WSON RWA Processes (no impairments)
In [RFC6163] three alternative process architectures were given for
performing routing and wavelength assignment. These are shown
schematically in Figure 1.
+-------------------+
| +-------+ +--+ | +-------+ +--+ +-------+ +---+
| |Routing| |WA| | |Routing|--->|WA| |Routing|--->|DWA|
| +-------+ +--+ | +-------+ +--+ +-------+ +---+
| Combined | Separate Processes Separate Processes
| Processes | WA performed in a
+-------------------+ Distributed manner
(a) (b) (c)
Figure 1 RWA process alternatives.
Detail description of each alternative can be found in [RFC6163].
Lee & Bernstein Expires January 7, 2012 [Page 5]
Internet-Draft PCEP Extension for WSON Impairments July 2011
1.2. WSON IA-RWA Processes
In [WSON-IMP] impairments were addressed by adding an "impairment
validation" (IV) process. For approximate impairment validation three
process alternatives were given in [WSON-IMP] and are shown in Figure
2. Since there are many possible alternative combinations, these are
just three examples. Please note that the requirements for all
possible architectures can be reduced to the cases in Figure 3 in
section 2.
+-----------------------------------+
| +--+ +-------+ +--+ |
| |IV| |Routing| |WA| |
| +--+ +-------+ +--+ |
| |
| Combined Processes |
+-----------------------------------+
(a)
+--------------+ +----------------------+
| +----------+ | | +-------+ +--+ |
| | IV | | | |Routing| |WA| |
| |candidates| |----->| +-------+ +--+ |
| +----------+ | | Combined Processes |
+--------------+ +----------------------+
(b)
+-----------+ +----------------------+
| +-------+ | | +--+ +--+ |
| |Routing| |------->| |WA| |IV| |
| +-------+ | | +--+ +--+ |
+-----------+ | Distributed Processes|
+----------------------+
(c)
Figure 2 Process flows for the three main approximate impairment
architectural alternatives.
These alternatives have the following properties and impact on PCEP
requirements in this document.
1. Combined IV and RWA Process - Here the processes of impairment
validation, routing and wavelength assignment are aggregated into
a single PCE. The requirements for PCC-PCE interaction with such a
combined IV-RWA process PCE is addressed in this document.
Lee & Bernstein Expires January 7, 2012 [Page 6]
Internet-Draft PCEP Extension for WSON Impairments July 2011
2. IV-Candidates + RWA Process - As explained in [WSON-IMP]
separating the impairment validation process from the RWA process
maybe necessary to deal with impairment sharing constraints. In
this architecture one PCE computes impairment candidates and
another PCE uses this information while performing RWA. The
requirements for PCE-to-PCE interaction of this architecture will
be addressed in this document.
3. Routing + Distributed WA and IV - Here a standard path computation
(unaware of detailed wavelength availability or optical
impairments) takes place, then wavelength assignment and
impairment validation is performed along this path in a
distributed manner via signaling (RSVP-TE). This alternative
should be covered by existing or emerging GMPLS PCEP extensions
and does not present new WSON specific requirements.
2. WSON PCE Architectures and Requirements
In the previous section we reviewed various process architectures for
implementing RWA with and without regard for optical impairment. In
Figure 3 we reduce these alternatives to two PCE based
implementations. In Figure 3(a) we show the three processes of
routing, wavelength assignment and impairment validation accessed via
a single PCE. The implementation details of the interactions of the
processes are not subject to standardization in this case only the
PCC to PCE communications.
In Figure 3(b) the impairment validation process is implemented in a
separate PCE. Here the RWA-PCE acts as a coordinator and the PCC to
RWA-PCE interface will be the same as in Figure 3(a), however in this
case we have additional requirements for the RWA-PCE to IV-PCE
interface.
Lee & Bernstein Expires January 7, 2012 [Page 7]
Internet-Draft PCEP Extension for WSON Impairments July 2011
+-----------------------------------+
+-----+ | +--+ +-------+ +--+ |
| | | |IV| |Routing| |WA| |
| PCC |<----->| +--+ +-------+ +--+ |
| | | |
+-----+ | PCE |
+-----------------------------------+
(a)
+----------------------+ +--------------+
+-----+ | +-------+ +--+ | | |
| | | |Routing| |WA| | | IV |
| PCC |<----->| +-------+ +--+ |<--->| candidates |
| | | | | |
+-----+ | RWA-PCE (coordinator)| | IV-PCE |
+----------------------+ +--------------+
(b)
Figure 3 PCE architectures for RWA.
2.1. RWA PCC to PCE Interface
The PCC to PCE interface of Figure 3(a) and the PCC to RWA-PCE
(coordinator) interface of Figure 3(b) are the same and we will cover
both in this section. The following requirements for these interfaces
are arranged by use cases:
2.1.1. A new RWA path request
The PCReq Message SHOULD include some specific measure of optical
signal quality to which all feasible paths should conform:
o The BER limit
o OSNR + Margin
o PMD
o Q factor
If the PCReq Message does not include the BER limit and no default
BER limit is provisioned at the PCE then the PCE will return an error
specifying that a BER limit must be provided.
Lee & Bernstein Expires January 7, 2012 [Page 8]
Internet-Draft PCEP Extension for WSON Impairments July 2011
"Margin" means "insurance" (e.g. 3~6dB) for suppliers and operators
against unpredictable degradation and other degradation not included
in the provided estimates such as that due to fiber nonlinearity.
2.1.1.1. Signal Quality Measure TLV
This TLV represents all impairment constraints that need to be
considered by the PCE to calculate a path that passes the requested
measure of signal quality for a signal for a given source and
destination.
This TLV is repeated one after another until all signal quality types
are specified.
The TLV type is TBD.
The TLV data is defined as follow:
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|P| Signal Quality Type | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Threshold |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
The P bit (1 bit): Indicates if the associated impairment is a path
level or not.
The P bit is set to 1 indicates that the associated impairment is a
path level. This means that the impairment is associated with the
end-to-end path and the threshold must be satisfied on a path level.
The P bit is set to 0 indicates that the associated impairment is a
link level. This means the impairment is associated with the link and
the threshold must be satisfied on every link of the end-to-end path.
The Signal Quality Type (15 bits): indicates the kind of optical
signal quality of interest.
0: reserved
1: The BER limit
Lee & Bernstein Expires January 7, 2012 [Page 9]
Internet-Draft PCEP Extension for WSON Impairments July 2011
2: OSNR + Margin
3: PMD
4: Q factor
5-up: Reserved for future use
Threshold (32 bits) indicates the threshold (upper or lower) to which
the specified signal quality measure must satisfy for the path/link
(depending on the P bit).
The reserved bits MUST be set to 0 on transmit and MUST be ignored on
receive.
2.1.2. A new RWA path reply
The PCRep Message MUST include the route, wavelengths assigned to the
route, and an indicator that says if the path conforms to the
required quality or not. In the case where a valid path is not found,
the PCRep Message MUST include why the path is not found (e.g., no
route, wavelength not found, BER failure, etc.)
2.1.2.1. Signal Quality Measure TLV
This TLV represents the result of the requested measure of signal
quality for a signal for a given source and destination.
This TLV is repeated one after another until all signal quality types
are specified.
The TLV type is TBD.
The TLV data is defined as follow:
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|P| Signal Quality Type | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Signal Quality Value |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Lee & Bernstein Expires January 7, 2012 [Page 10]
Internet-Draft PCEP Extension for WSON Impairments July 2011
The P bit (1 bit): Indicates if the associated signal quality measure
has passed the threshold or not.
The P bit is set to 1 indicates that the associated signal quality
measure has passed the threshold.
The P bit is set to 0 indicates that the associated signal quality
measure has failed the threshold.
The Signal Quality Type (15 bits): indicates the kind of optical
signal quality of interest.
0: reserved
1: The BER limit
2: OSNR + Margin
3: PMD
4: Q factor
5-up: Reserved for future use
Signal Quality Value (32 bits) indicates the actual estimated value
of the specified signal quality measure for the end-to-end path.
The reserved bits MUST be set to 0 on transmit and MUST be ignored on
reception.
Lee & Bernstein Expires January 7, 2012 [Page 11]
Internet-Draft PCEP Extension for WSON Impairments July 2011
2.2. RWA-PCE to IV-PCE Interface
In [WSON-IMP] a sequence diagram for the interaction of the PCC, RWA-
PCE and IV-PCE of Figure 3(b) was given and is repeated here in
Figure 4. The interface between the PCC and the RWA-PCE (acting as
the coordinator) was covered in section 2.1.
+---+ +-------------+ +-----------------+
|PCC| |RWA-Coord-PCE| |IV-Candidates-PCE|
+-+-+ +------+------+ +---------+-------+
...___ (a) | |
| ````---...____ | |
| ```-->| |
| | |
| |--..___ (b) |
| | ```---...___ |
| | ```---->|
| | |
| | |
| | (c) ___...|
| | ___....---'''' |
| |<--'''' |
| | |
| | |
| (d) ___...| |
| ___....---''' | |
|<--''' | |
| | |
| | |
Figure 4 Sequence diagram for the interactions between PCC, RWA-
Coordinating-PCE and the IV-Candidates-PCE.
The interface between the RWA-Coord-PCE and the IV-Candidates-PCE is
specified by the following requirements:
1. The PCReq Message from the RWA-Coord-PCE to the IV-Candidate-PCE
MUST include an indicator that more than one (candidate) path
between source and destination is desired.
2. The PCReq message from the RWA-Coord-PCE to the IV-Candidates-PCE
MUST include a limit on the number of optical impairment qualified
paths to be returned by the IV-PCE.
Lee & Bernstein Expires January 7, 2012 [Page 12]
Internet-Draft PCEP Extension for WSON Impairments July 2011
3. The PCReq message from the RWA-Coord-PCE to the IV-Candidates-PCE
MAY include wavelength constraints. Note that optical impairments
are wavelength sensitive and hence specifying a wavelength
constraint may help limit the search for valid paths. This
requirement has been already covered in [PCEP-RWA] and is
presented here for an illustration purpose.
4. The PCRep Message from the IV-Candidates-PCE to RWA-Coord-PCE MUST
include a set of optical impairment qualified paths along with any
wavelength constraints on those paths.
5. The PCRep Message from the IV-Candidates-PCE to RWA-Coord-PCE MUST
indicate "no path found" in case where a valid path is not found.
6. The PCReq Message from the RWA-Coord-PCE to the IV-Candidate-PCE
MAY include one or more specified paths and wavelengths that is to
be verified by the IV-PCE. This requirement is necessary when the
IV-PCE is allowed to verify specific paths.
Note that once the Combined RWA Process PCE receives the resulting
paths from the IV Candidates PCE, then the Combined RWA PCE computes
RWA for the IV qualified candidate paths and sends the result back to
the PCC.
2.2.1. A new impairment-validated (IV) path request
Details on encoding are TBD.
2.2.2. A new impairment-validated (IV) path reply
Details on encoding are TBD.
3. Manageability Considerations
Manageability of WSON Routing and Wavelength Assignment (RWA) with
PCE must address the following considerations:
3.1. Control of Function and Policy
In addition to the parameters already listed in Section 8.1 of
[RFC5440], a PCEP implementation SHOULD allow configuring the
following PCEP session parameters on a PCC:
o The ability to send a WSON IA-RWA request.
Lee & Bernstein Expires January 7, 2012 [Page 13]
Internet-Draft PCEP Extension for WSON Impairments July 2011
In addition to the parameters already listed in Section 8.1 of
[RFC5440], a PCEP implementation SHOULD allow configuring the
following PCEP session parameters on a PCE:
o The support for WSON IA-RWA.
o The maximum number of synchronized path requests associated with
WSON IA-RWA per request message.
o A set of WSON IA-RWA specific policies (authorized sender, request
rate limiter, etc).
These parameters may be configured as default parameters for any PCEP
session the PCEP speaker participates in, or may apply to a specific
session with a given PCEP peer or a specific group of sessions with a
specific group of PCEP peers.
3.2. Information and Data Models, e.g. MIB module
Extensions to the PCEP MIB module defined in [PCEP-MIB] should be
defined, so as to cover the WSON IA-RWA information introduced in
this document. A future revision of this document will list the
information that should be added to the MIB module.
3.3. Liveness Detection and Monitoring
Mechanisms defined in this document do not imply any new liveness
detection and monitoring requirements in addition to those already
listed in section 8.3 of [RFC5440].
3.4. Verifying Correct Operation
Mechanisms defined in this document do not imply any new verification
requirements in addition to those already listed in section 8.4 of
[RFC5440]
3.5. Requirements on Other Protocols and Functional Components
The PCE Discovery mechanisms ([RFC5089] and [RFC5088]) may be used to
advertise WSON IA-RWA path computation capabilities to PCCs.
Lee & Bernstein Expires January 7, 2012 [Page 14]
Internet-Draft PCEP Extension for WSON Impairments July 2011
3.6. Impact on Network Operation
Mechanisms defined in this document do not imply any new network
operation requirements in addition to those already listed in section
8.6 of [RFC5440].
4. Security Considerations
This document has no requirement for a change to the security models
within PCEP [PCEP]. However the additional information distributed in
order to address the RWA problem represents a disclosure of network
capabilities that an operator may wish to keep private. Consideration
should be given to securing this information.
5. IANA Considerations
A future revision of this document will present requests to IANA for
codepoint allocation.
6. References
6.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC3471] Berger, L., "Generalized Multi-Protocol Label Switching
(GMPLS) Signaling Functional Description", RFC 3471,
January 2003.
[RFC3473] Berger, L., Ed., "Generalized Multi-Protocol Label
Switching (GMPLS) Signaling Resource ReserVation Protocol-
Traffic Engineering (RSVP-TE) Extensions", RFC 3473,
January 2003.
[RFC5440] Vasseur, JP., Ed. and JL. Le Roux, Ed., "Path Computation
Element (PCE) communication Protocol (PCEP)", RFC 5440,
March 2009.
Lee & Bernstein Expires January 7, 2012 [Page 15]
Internet-Draft PCEP Extension for WSON Impairments July 2011
6.2. Informative References
[RFC6163] Y. Lee, G. Bernstein, W. Imajuku, "Framework for GMPLS and
PCE Control of Wavelength Switched Optical Networks", RFC
6163, April 2011.
[WSON-IMP] Lee, Y. and Bernstein, G. (Editors), and D. Li, "Framework
for GMPLS and PCE Control of Wavelength Switched Optical
Networks", draft-bernstein-ccamp-wavelength-switched, work
in progress.
[PCEP-RWA] Y. Lee, G. Bernstein, J. Martensson, T. Takeda and T.
Otani, "PCEP Requirements for WSON Routing and Wavelength
Assignment", draft-lee-pce-wson-routing-wavelength, work in
progress.
[RFC5088] Le Roux, JL., Ed., Vasseur, JP., Ed., Ikejiri, Y., and R.
Zhang, "OSPF Protocol Extensions for Path Computation
Element (PCE) Discovery", RFC 5088, January 2008.
[RFC5089] Le Roux, JL., Ed., Vasseur, JP., Ed., Ikejiri, Y., and R.
Zhang, "IS-IS Protocol Extensions for Path Computation
Element (PCE) Discovery", RFC 5089, January 2008.
[RFC4655] Farrel, A., Vasseur, J., and J. Ash, "A Path Computation
Element (PCE)-Based Architecture", RFC 4655, August 2006.
[RFC4657] Ash, J. and J. Le Roux, "Path Computation Element (PCE)
Communication Protocol Generic Requirements", RFC 4657,
September 2006.
Authors' Addresses
Young Lee (Ed.)
Huawei Technologies
1700 Alma Drive, Suite 100
Plano, TX 75075, USA
Phone: (972) 509-5599 (x2240)
Email: ylee@huawei.com
Lee & Bernstein Expires January 7, 2012 [Page 16]
Internet-Draft PCEP Extension for WSON Impairments July 2011
Greg Bernstein (Ed.)
Grotto Networking
Fremont, CA, USA
Phone: (510) 573-2237
Email: gregb@grotto-networking.com
Jonas Martensson
Acreo
Email:Jonas.Martensson@acreo.se
Tomonori Takeda
NTT Corporation
3-9-11, Midori-Cho
Musashino-Shi, Tokyo 180-8585, Japan
Email: takeda.tomonori@lab.ntt.co.jp
Takehiro Tsuritani
2-1-15 Ohara, Fujimino, Saitama, 356-8502, JAPAN
KDDI R&D Laboratories Inc.
Phone: +81-49-278-7806
Email: tsuri@kddilabs.jp
7. Acknowledgments
This document was prepared using 2-Word-v2.0.template.dot.
Copyright (c) 2011 IETF Trust and the persons identified as authors
of the code. All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:
o Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
o Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in
the documentation and/or other materials provided with the
distribution.
o Neither the name of Internet Society, IETF or IETF Trust, nor the
names of specific contributors, may be used to endorse or promote
products derived from this software without specific prior written
permission.
Lee & Bernstein Expires January 7, 2012 [Page 17]
Internet-Draft PCEP Extension for WSON Impairments July 2011
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
Lee & Bernstein Expires January 7, 2012 [Page 18]
Internet-Draft PCEP Extension for WSON Impairments July 2011
Lee & Bernstein Expires January 7, 2012 [Page 19]